Search Article Keyword  
PubMed Submission Abstarct PDF Cited  Click Count: 2406 DownLoad Count: 1067 

ISSN 1007-9327 CN 14-1219/R  World J Gastroenterol  1998; 4(5):397-403

Basaloid squamous carcinoma of esophagus: a clinicopathological, immunohistochemical and electron microscopic study of sixteen cases

Xin-Hua
Zhang, Gui-Qin Sun, Xiao-Jun Zhou, Hui-Fang Guo, Tai-He Zhang


Xin-Hua Zhang, Gui-Qin Sun, Xiao-Jun Zhou, Hui-Fang Guo, Tai-He Zhang, Department of Pathology, Chinese PLA General Hospital of Nanjing Command Area, Nanjing 210002, China
Dr.
Xin-Hua Zhang, male, born on 1960-05-11 in Tiaotai County, Zhejiang Province, Han nationality, graduated from Shanghai Second Medical University as a postgraduate in 1988, vice chief doctor, majoring diagnostic pathology, having 15 papers published.
Correspondence to: Dr.
Xin-Hua Zhang, Department of Pathology, Chinese PLA General Hospital of Nanjing Command Area, 305 East Zhongshan Road, Nanjin 210002, China
Telephone: +86-25-3387871-58192, Fax.+86-25-4402352 E-mail address:zhouxj
public1.ptt.js.cn
Received: 1998-04-20

Subject headings: esophageal neoplasms/pathology; esophageal neoplasms/ultrastructure; carcinoma, squamous cell/pathology; carcinoma, squamous cell/ultrastructure

Zhang XH, Sun GQ, Zhou XJ, Guo HF, Zhang TH.Basaloid squamous carcinoma of esophagus: a clinicopathological, immunohistochemical and electron microscopic study of sixteen cases.World J Gastroenterol, 1998;4(5):397-403

Abstract
AIM: To further clarify the clinicopathological, immunohistochemical and electron microscopic features, and prognostic aspect of basaloid squamous carcinoma (BSC), a rare esophageal carcinoma.

METHODS: We reviewed 763 documented cases of esophageal malignancies from year (1977-1996) from our hospital, and discovered 16 (2.1%) cases of BSC. The clinicopathological features of these cases were evaluated. Immunohistochemistry (S-P method), histochemical stains, and electron microscopy were used to further characterize the neoplasm.

RESULTS: The tumors were classified into stages
(n=1), A (n=6), B (n=2), (n=5), and (n=2) according to the criteria of the UICC TNM classification system of malignant tumors (1987). Most neoplasms were located in the mid third of the esophagus. Grossly, they had a similar appearance of conventional esophageal carcinoma, but showed a typical cytoarchitectural pattern of BSC histologically. The most important histologic feature of this tumor is carcinoma with a basaloid pattern, intimately associated with squamous cell carcinoma, dysplasia, or focal squamous differentiation. The basaloid cells were round to oval in shape with scant cytoplasm, arranged mainly in the form of solid, smooth-contoured lobules with peripheral palisading. A panel of immunostains were used for the basaloid component of the tumor with the following results: CK(Pan) 14/16(+); EMA 16/16 (+); Vimentin 4/16 (+); S-100 protein 7/16 (+). CEA and smooth muscle actin were negative. Electron microscopy (EM) revealed that the basaloid cells were poorly differentiated, with a few desmosomes and fibrils, and numerous free and polyribosome. Of the 11 patients with adequate follow-up 8 died within 2 years, with an average survival time of 16.2 months. No stage , or cases survived beyond 5 years. The one-year survival rate was 60% and two-year 20%.

CONCLUSION: The BSC of esophagus is a distinct clinicopathological entity with poor prognosis. The cellular differentiation and biologic behavior of esophageal BSC were assumed to occupy a station intermediate between that of conventional squamous cell carcinoma and small undifferentiated cell carcinoma.

INTRODUCTION
The term basaloid squamous carcinoma (BSC) was first proposed by Wain et al in 1986 to describe a rare, aggressive neoplasm with a predilection occuring in the hypopharynx, base of tongue, larynx
1, and late in the esophagus2, nasal and oral cavity3,4, tonsil5, nasopharynx6, trachea, bronchus and lung7-9, and other sites including external ear10, anal canal, vulva and penile11-13. It is characterized by basaloid carcinoma intimately associated with squamous cell carcinoma, dysplasia, carcinoma in situ , or focal squamous differentiation. Approximatelly 400 cases of BSC have been reported in the world literature by the end of 1996, including 69 cases of BSC of esophagus. In a recent review of esophageal neoplasms at the Department of Pathology of our hospital, sixteen such tumors were identified. In this paper, we report about the clinicopathological and immunohistochemical features of these 16 cases of BSC of esophagus to further categorize this lesion. Electron microscopic features of seven cases, and their prognosis were also described.

MATERIAL AND METHODS
All resected esophageal tumor slices examined over the last 20 years (1977-1996) at the Department of Pathology of our hospital were reviewed. Of 763 cases of esophageal malignancies, 16 showed the histopathologic pattern of basaloid squamous carcinoma
1. Clinical data, including age and sex, location and size, and gross appearance were obtained from the medical records. Follow-up information was available in 11 cases. All surgical specimens were fixed in 10% formalin and processed in the usual way for paraffin embedding. In addition to routine hematoxylin and eosin -(H&E) staining, periodic acid-Schiff (PAS) with or without diastase, and Alcian blue (pH 2.5) staining was performed.
       Seven cases was also reviewed electron microscopically. Immunohistochemistry was performed on paraffin sections of representative portions of the tumors using the streptavidin peroxidase method (S-P method)
14. The S-P Kit was obtained from Zymed Laboratories Inc, USA. The prediluted antibodies against cytokeratin (Pan) (CK), carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), vimentin, smooth muscle specific actin (SMA), and S-100 protein were products of Maxim Biotech, Inc, USA. The results of immunohistochemical stains were recorded as negative (-) , weakly positive (less than 10% positive cells), positive (10%-15% positive cells) and strongly positive (more than 50% positive cells).

RESULTS
Demographic and clinical data
The clinicopathologic, TNM staging, therapeutic, and follow-up data are summariszed in Table 1. The patients ranged in age from 42 to 72, with a mean age of 58 years (median 57 years). There were 9 males and 7 females, all were Chinese. The patients presented with progressive dysphagia. The duration of symptoms ranged from 1 to 8 months. All cases were treated with either curative or palliative esophagectomy. Eleven patients were further treated by chemotherapy. Eleven of the 16 esophageal tumors were located at the middle third of the esophagus, 4 at the lower third, and 1 at the upper third. Their size ranged from 1.3cm to
7.0cm in greatest diameter. The gross appearance of the tumors in this series were infiltrative lesions in 4 cases, protuberant lesion in 6, ulcerative lesion in 5, and a polypoid mass in 1. The staging of the lesions followed the criteria of the UICC TNM classification system of malignant tumors, 1987
15. The tumors were then classified as stage (n=1), stage A (n=6), stage B (n=2), stage (n=5), and stage (n=2).

Table 1 Clinicopathological, Staging, Therapeutic and Follow-up Data in 16 Patients with Esophageal BSC

Case
No.

Age/
sex

Tumor
location

Tumor size
(cm)

Gross
appearance

Stage

Therapy

Mitoses
(per 10HPF)

Follow-up

Surgery

Chemo-
therapy

1

42/F

Lower 1/3

2.5×1.5×0.6

Polypoid

A(T2N0M0)

Curative
esophagectomy

 

198

Not available

2

56/M

Middle 1/3

2.5×2.0×0.8

Protuberant

A(T3N0M0)

Curative
esophagectomy

 

51

Not available

3

50/F

Lower 1/3

4.0×2.0×1.0

Ulcerative

(T3N1M0)

Curative
esophagectomy

 

74

Not available

4

62/M

Middle 1/3

3.5×1.5

Protuberant

A(T2N0M0)

Curative
esophagectomy

+

86

Died of tumor
recurrence at 18mo

5

56/M

Lower 1/3

4.3×2.8×1.8

Protuberant

(T1N0M0)

Curative
esophagectomy

+

60

Alive & well at 10a

6

62/M

Upper 1/3

2.8×1.0×0.7

Ulcerative

(T3N1M0)

Curative
esophagectomy

+

45

Died of tumor, recurrence 14mo after operation

7

54/M

Middle 1/3

4.0×2.8

Infiltrative

(T2N0M1)

Palliative
esophagectomy

+

47

Metastases to lung and pleura, died 12mos after operation

8

60/F

Middle 1/3

2.5
(in diameter)

Infiltrative

(T3N1M0)

Curative
esophagectomy

+

98

Died of metastases and recurrence 8mo later

9

72/M

Middle 1/3

5.5×2.0

Ulcerative

A(T3N0M0)

Curative
esophagectomy

 

136

Not available

10

62/F

Middle 1/3

3.5×2.0×3.0

Protuberant

A(T2N0M0)

Curative
esophagectomy

 

49

Not available

11

49/M

Middle 1/3

3.5×3.0

Ulcerative

(T4N1M1)

Paliative
esophagectomy

+

54

Metastases to lung and brain, Died 9mo after operation

12

70/M

Lower 1/3

5.0×2.0×1.5

Infiltrative

(T3N1M0)

Curative
esophagectomy

+

82

Died of tumor recurrence 4a after operation

13

67/M

Middle 1/3

5.0×4.8×2.0

Infiltrative

A(T3N0M0)

Curative
esophagectomy

+

104

Died 16mo after operation

14

57/F

Middle 1/3
(with two lesions)

2.0×1.5
1.3(in diameter )

Ulcerative

B(T1N1M0)

Curative
esophagectomy

+

60

Died 3mo after diagnosis

15

57/F

Middle 1/3

7.0×5.0×3.0

Protuberant

(T4N1M0)

Palliative
esophagectomy

+

85

Died 8mo after operation

16

52/F

Middle 1/3

4.0×2.5

Protuberant

B(T2N1M0)

Curative
esophagectomy

+

105

Alive 4mo after operation

The criteria of the UICC TNM classification system (1987) was used.

       Follow-up information was obtained from 11 cases. Nine patients died 3 to 48 months after operation. The average survival of these nine patients was 16.2 months. One patient is alive disease free at 10 years, and another patient is still on chemotherapy 4 months after operation. The survival rate was 60% at 12 months, and 20% at 24 months.

Histopathologic findings
All 16 neoplasms fulfilled the basic histological features of BSC
1. The basaloid cells arranged mainly in the form of solid, smooth contoured lobules, some cases also in the form of solid sheets, anastomosing trabeculae, or microcystic structures (Figure 1) . In fourteen cases, the basaloid component was found to represent between 60% to 95% of the tumor examined. In the remaining two cases (case 6 and case 7), it accounted for less than 20% and 30% respectively. In all 16 cases, the intertrabecular spaces and stroma of the tumors had eosinophilic hyaline materials. These hyaline materials, extending between and replacing the tumor cells, were PAS positive both before and after diastase treatment (Figure 2). In 8 cases, the microcystic spaces, some of which lined by PAS-positive lamina material, contained basophilic mucoid matrix which was Alcian blue positive but PAS negative. The basaloid cells were round to oval in shape, with scant, amphophilic cytoplasm, but sometimes it was abundant and clear. The nuclei showed either dark, hyperchromatin without nucleoli or dusty chromatin, vacuolated nucleoplasm with 1 to 3 small distinct nucleoli. The nuclear pleomorphism was frequently observed in all cases. The number of mitotic figures (including atypical ones) was extremely high, ranging from 45 to 198 mitoses per 10 high-power fields. The cells at the edges of the basaloid islands tended to show peripheral nuclear palisading. Comedo necrosis was found within the basaloid lobules in all cases (Figure 3).
       An intimately associated squamous cell component was another major histopatholog ic feature of the tumor. In seven cases, invasive, keratinizing squamous cell carcinoma covered 5%-80% and merged with the basaloid component. Two cases (cases 1 and 7) showed conventional squamous cell carcinoma as well as spindle cell component, the latter infiltrated between the basaloid lobules (Figure 4). In case 5 and 13 carcinomas in situ were found in the overlying epithelium. Four of the 16 (case 3, 11, 15 and 16) cases only had focal squamous differentiation and keratinization in the basaloid lobules (Figure 3) . In one case (case 1 4), squamous cell dysplasia, squamous cell carcinoma in situ in the overlying epithelium as well as invasive squamous cell carcinoma and small cell carcionoma were the associated components of basaloid cell carcinoma with areas of ductular or glandular differentiation.

Table 2 Histochemical and immunohistochemical findings

Case

Component

CK

EMA

CEA

Vim

S-100

SMA

Stroma

AB

PAS

D-PAS

1

B

+

+

-

-

-

-

+

+

+

 

S

++

++

-

-

-

-

 

 

 

 

SP

-

-

-

++

-

-

 

 

 

2

B

+++

+

-

+

-

-

-

+

+

 

S

+++

+++

-

-

-

-

 

 

 

3

B

++

+

-

-

-

-

+

+

+

 

S

+++

+

-

-

-

-

 

 

 

4

B

++

+

-

-

-

-

-

+

+

 

S

+++

+++

-

-

-

-

 

 

 

5

B

+

+

-

-

-

-

+

+

+

 

S

+

+++

+

-

-

-

 

 

 

6

B

+++

+

-

++

-

-

-

+

+

 

S

+++

+++

+

-

-

-

 

 

 

7

B

+++

-

-

-

++

-

+

+

+

 

S

+++

+++

-

-

-

-

 

 

 

 

SP

-

-

-

++

-

+

 

 

 

8

B

++

+

-

-

-

-

+

+

+

 

S

++

++

-

-

-

-

 

 

 

9

B

+++

++

-

-

+

-

-

+

+

 

S

+++

++

-

-

-

-

 

 

 

10

B

+

+

-

-

+

-

-

+

+

 

S

++

+++

-

-

-

-

 

 

 

11

B

-

++

-

-

-

-

-

+

+

 

S

+++

++

-

-

-

-

 

 

 

12

B

++

++

-

-

+

-

+

+

+

 

S

+++

++

-

-

-

-

 

 

 

13

B

-

+

-

-

+

-

-

+

+

 

S

++

++

-

-

-

-

 

 

 

14

B

+++

++

-

-

-

-

+

+

+

 

S

+++

++

-

-

-

-

 

 

 

 

SM

++

++

-

-

-

-

 

 

 

15

B

++

+

-

+++

+++

-

+

+

+

 

S

+++

+++

++

-

-

-

 

 

 

16

B

+

+

-

++

+

-

-

+

+

 

S

+++

++

-

-

-

-

 

 

 

 B: basaloid cell; S: squamous cell; SP: spindle cell; SM: small cell; D PAS: diastase treating PSA stain

Immunohistochemical findings
Table 2 gives the immunohistochemical staining pattern of the 16 neoplasms studied. All squamous cell component, and basaloid cell component of 14 cases showed variable intracytoplasmic staining for cytokeratin (Pan) (Figure 5) . But the spindle cells in case 1 and case 7 had negative staining for CK. EMA positivit y was also demonstrated in nearly all the cases, nevertheless, the reactivity was focal and faint in the basaloid component, and in some cases, CK and EMA staining highlighted the glandular spaces focally. CEA was weakly expressed in squamous area of three cases. Vimentin immunoreactivity was found focally in the basaloid component of three cases and in the spindle cells in case 1 and case 7. In six cases, S-100 protein positive reaction was focally found within the lobules of basaloid component. However, the basaloid component in case 15 had diffusely and strongly positive staining for vimentin and S-100 protein (Figure 6). SM-actin immunoreactivity was absent in all cases except the spindle cell component in case 7.

Figure 1 The basaloid cells arranged in the form of anastomosing trabeculae and microcystic structures. H&E, ×200
Figure 2 The intertrabecular and microcystic spaces filled with eosinophilic hyaline material which were PAS positive. ×100
Figure 3 Focal squamous differentiation and keratinization and comedo necrosis were found in the basaloid lobules. H&E, ×100
Figure 4 Basaloid cell carcinoma with spindle cell component. H&E, ×200
Figure 5 Immunohistochemical studies (S-P method) show positivity in the basaloid components for cytokeratin (Pan). ×200
Figure 6 The basaloid components in case 15 are diffusely and strongly positive staining for (a) vimentin and (b) S-100 protein. ×200
Figure 7 Electron microscopic photograph of esophage al BSC demontrating replicated basal lamina in fingerprint-like pattern filled in the intertrabecular and intercellular spaces. ×20,000
Figure 8 Electron microscopicphotograph of esophageal BSC demonstrating well-formed intercellular desmosomes. ×16,000

Electron microscopic features
Seven cases were examined under electron microscopy (case 9, 10, 11, 12, 14, 15, 16). Lobules of basaloid cells were seperated from the stroma by an external lamina. The cells within the lobules had widened intercellular spaces. The microcystic and intertrabecular spaces identified by light microscopy were lined by basal membranes and filled with either loose reduplicated or compact globoid basal lamina, showing fingerprint like pattern (Figure 7) . The basaloid cells were polygonal. The nuclei had oval profiles and there were irregular identations, containing finely dispersed chromatin and small clumps of hetero chromatin. One to three compact nucleoli were present in some nuclei. Within the cytoplasm were numerous free and polyribosomes, a few desmosomes, tonofilaments and mitochondria (Figure 8) , but rare other organelles, and absence of neuro secretory granules.

DISCUSSION
Before the term basaloid squamous carcinoma was introduced by Wain
1 in 1986, most malignancies of the esophagus with similar histopathologic pattern to BSC were diagnosed as adenoid cystic carcinoma (ACC). But scrutiny of the published reports showed that most cases were histologically identical to BSC16,17, and behaved more aggressively than ACC. Tumors with identical morphology and similar clinical behavior have also been noted in other areas such as the uterine cervix18, anal canal19 and lung9. Other terms had also been used to describe this tumor such as adenosquamous carcinoma, poorly-differentiated squamous cell carcinoma, and small undifferentiated cell carcinoma. In the recent World Health Organization classification of esopha geal tumors, there is no mention of this newly recognized type of basaloid squamous carcinoma 20. But the presence of lobules or cords of small, closely packed basaloid cells with scant cytoplasm, with or without small cystic spaces and hyalinized stroma, as well as an associated abnormal squamous cell component makes this tumor different from other common esophageal carcinomas. They have identical clinical and histopathologic features to that of BSC occuring in the larynx, pharynx and base of tougue described first by Wain et al, and belong to the same entity of malignant carcinoma.
       In this series, sixteen cases of BSC of esophagus were found, accounting for 2.1% of 763 esophgeal carcinomas reviewed. The incidence is higher than that previously reported
2,21, but similar to the incidence by Abe et al22. This may be due to the difference of case selection. In our series, all cases were confirmed by esophagectomy. Morover, the main portion of each tumor is composed of basaloid carcinoma in 14 of 16 BSC cases as described in the literature1, but in the remaining two, the major portion of the tumor is composed of squamous cell carcinoma, the basaloid component accounting for less than 30%. The most common location of the tumor is the middle third of the esophagus (11/16) . The gross appearance of BSC is similar to that of other squamous cell carcinoma, only the cut surface in the former is more delicate.
       BSC of esophagus should be distinguished from adenoid cystic carcinoma (ACC). The latter occurs more commonly in females, usually in women aged 40 to 60 years, with a mean age of 52 years
23, and with a more protracted clinical course. Histologically, the focal continuity with the abnormal surface epithelium or carcinoma in situ , an associated invasive squamous cell carcinoma, and focal squamous differentiation in the islands of basaloid cells are not features of ACC, while alone or in combination, they have been found in all cases in the present series. The cells in ACC seem bland with mild pleomorphic nuclei and infrequent mitosis, and often exhibits identifiable two-cell-type differen ciation (palar ductal epithelium and darker basaloid cells) and distinctive crib riform structures in nerve invaded areas24. Under electron microscopic examination, four cell types were revealed in ACC: the intercalated duct cells; the secretory cells; the myoepithelium; and the pluripotential reserve/stem cells. These cells, especially the secretory cells and myoepithelium, were not noted by either immunohistochemical staining or electron microscopic examination in current series. The correct differential diagnosis between BSC and ACC is of important prognostic value. Basaloid squamous carcinoma of the esophagus is associated with poor outcome. The overall 3-year survival rate of BSC has been estimated at 28.5%25. In our series, most patients had developed into advanced stages at their presentation. Of the 11 patients with adequate follow-up, 8 died within 2 years from diagnosis, the survival rate being 60% at 12 month and 20% at 24 month. While the cumulative survival rates for patients with grade , and of ACC were 92%, 65% and 14% at 5 years24. Epstein and coworkers17 have proposed labelling tumors in the esophagus with histological features of BSC as “carcinoma with adenoid cystic differentiation” instead of “adenoid cystic carcinoma”. But we think this descriptive term is too long and inconvenient to use, and the prognosis is apt to be overestimated by clinicians. In contrast, the term basaloid squamous carcinoma is shorter and more convenient to use. Furthermore, the two tumor elements, basaloid and squamous, of the term make it unique and differ from other kinds of tumors.
       Cytoplasmic staining of BSC for a variety of antibodies to cytokeratins of different molecular weight has demonstrated variable staining with these antibodies2,8,26,27. In this study, the faint immunoreactivity pattern for EMA in basaloid component, and focal positivity for CK in some cases, together with intercellular desmosomes and cytoplasmic organelles and fibrils revealed by electron microscope provides an evidence that the basaloid cells in BSC may be largely undifferentiated, sometimes exhibiting focal tubular or squamous differentiation. Although Klijanienko and associates27 suggested that the immunoph enotype of S-100 protein-positive and vimentin positive cells would indicate adiagnosis of adenoid cystic carcinoma, our seven S-100 protein-positive cases and four vimentin positive cases are typical BSC rather than ACC. The S-100 protein-positive cells are not dendritic Langerhans cells as described by the same authors, but basaloid carcinoma cells.
       The exact line of differentiation or pathogenesis of basaloid squamous carcinoma is still unknown. Some reported cases of BSC were associated with smoking and heavy alcohol consumption4,16, with a second primary tumor28, and rarely, with previous irradiation3. The relationship of this tumor with viral agents, i.e., Epstein Barr viruses vs BSC of the nasopharynx6, human papillomavirus vs BSC of the external genitalia, perineum, and anus11-13, has also been suggested by some authors. Based on the evidence provided by the present series and those reported in the literature, weagree with the theory of Ho et al29 that a totipotent primitive cell is the common precursor of all epithelium neoplasms of the esophagus. With certain carcinogenic stimulation, the totipotent cells are activated and transformed into malignant cells. These transformed cells may differentiate into neoplastic squamous cells, adenocarcinoma, basaloid cell carcinoma (reserve cell carcinoma) and small cell carcinoma. These basaloid and small cells are rather primitive and retain their potential for further differentiation into keratin-forming cells, spindle cell carcinoma, mucous producing cells, and so on. We believe that only those tumors bearing a biphasic cellular pattern of basaloid and squamous components in an intimate relationship should be considered true BSC, if not, as some cases reported by Brambilla et al 8, should be considered bas aloid (or reserve) cell carcinoma.
       The cellular differentiation and biologic behavior of BSC were assumed to occupy a station intermediate between that of conventional squamous cell carcinoma and small cell carcinoma. This assumptive placement into an intermediate position was based on the following. First, the clinical behavior of the tumors, which was less aggressive than that of small cell carcinoma (most of the patients died within 6 months from the time of diagnosis)
30, but more aggressive than that of conventional squamous cell carcinoma. In their 170 radical resected esophageal squamous cell carcinoma, Zheng et al31 reported that the 5-year survival rate was 47.3% for stage A cases, 22.2% for stage B, and 16.1% for stage ; while in our patients whose follow-up data were obtained, no stage , , or cases survived beyond 5 years. Second, the histopathologic feature of this tumor, i.e., the combination of basaloid and squamous carcinom a in most cases in our series and differentiation pattern in some cases. And third, numerous mitotic figures which were observed throughout tumor tissues in all our cases.
       In conclusion, the BSC of the esophagus represents a specific and unique clinico pathological entity with a highly aggressive behavior and a poor outcome. Identification of BSC is important because this lesion may be confused with less aggressive lesions, such as adenoid cystic carcinoma.

REFERENCES

1    Wain SL, Kier R, Vollmer RT, Bossen EH. Basaloid-squamous carcinoma of the tongue, hypopharynx, and larynx: report 
      of 10 cases. Hum Pathol, 1986;17(11):1158-1166
2    Tsang WYW, Chan JKC, Lee KC, Leung AKF, Fu YT. Basaloid-squamous carcinoma of the upper aerodigestive tract and
      so-called adenoid cystic carcinoma of the oesophagus: the same tumor type? Histopathology, 1991;19(1):35-46
3    Wan SK, Chan JK, Tse KC. Basaloid-squamous carcinoma of the nasal cavity.J Laryngol Otol, 1992;106(4):370-371
4    Coppola D, Catalano E, Tang CK, Elfenbein IB, Harwick R, Mohr R. Basaloid squamous cell carcinoma of floor of mouth.
      Cancer, 1993;72(8):2299-2305
5    Banks ER, Frierson HF Jr, Ovell JL. Fine needle aspiration cytologic findings in metastatic basaloid squamous carcinoma of
      the head and neck. Acta Cytol, 1992;36(2):126-131
6    Wan SK, Chan JKC, Lau WH, Yip TTC. Basaloid-squamous carcinoma of the naso-pharynx: an Epstein Barr
      virus-associated neoplasm compared with morphologically identical tumors occurring in other sites. Cancer,
      1995;76(10):1689-1693
7    Saltarelli MG, Fleming MV, Wenig BM, Gal AA, Mansour KA, Travis WD. Primary basaloid squamous cell carcinoma of
      the trachea. Am J Clin Pathol, 1995;104(5):594-598
8    Lin O, Harkin TJ, Jagirdar J. Basaloid-squamous cell carcinoma of the bronchus: report of a case with review of the
      literature. Arch Pothol Lab Med, 1995;119(12):1167-1170
9    Brambilla E, Moro D, Veale D, Brichon PY, Stoebner P, Paramelle B et al. Basal cell (basaloid) carcinoma of the lung:
      a new morphologic and phenotypic entity with seperate prognostic significance.Hum Pathol,1992;23(9):993-1003
10  Croce A, Bianchedi M, Neri G, Moretti A, Angelucci D. Basal cell and basosquamous carcinoma of the
      externalear. Immunohistochemical study. Acta Otorhinolaryngol Ital, 1994;14(4):367-375
11  Shroyer KR, Brookes CG, Markham NE, Shroyer AL. Detection of human papillomavirus in anorectal squamous cell
      carcinoma. Correlation with basaloid pattern of differentiation. Am J Clin Pathol, 1995;104(3):299-305
12  Kurman RJ, Toki T, Schiffman MH. Basaloid and warty carcinomas of vulva. Distinctive types of squamous cell
      carcinoma frequently associated with human papillomaviruses.Am J Surg Pathol, 1993;17(2):133-145
13  Gregoire L, Cubilla AJ, Reuter VE, Haas GP, Lancaster WD. Preferential association of human papillomavirus with
      highgrade histologic variants of penile-invasive squamous cell carcinoma.J Natl Cancer Inst,1995;87(22):1705-1709
14  Shi CR, Itzkowitz SH, Kim YS. A comparison of three immunoperoxidase techniques for antigen detection in
      colorectal carcinoma tissues.J Histochem Cytochem, 1988;36(3):317-322
15  Hermanek P, Sobin LH, eds. UICC TNM classification of malignant tumors. 4th ed. Berlin: Springer-Verlag, 1987:40-42
16  Sweeney EC, Cooney T. Adenoid cystic carcinoma of the esophagus. A light and electron microscopic study.Cancer,
      1980;45(6):1516-1525
17  Epstein JI, Sears DL, Tucker RS, Eagan JW Jr. Carcinoma of the esophagus with adenoid cystic differentiation.Cancer,
 
      1984;53(5):1131-1136
18  Ferry JA, Scully RE. “Adenoid cystic” carcinoma and adenoid basal carcinoma of the uterinc cervix: a study of 28 cases.
      Am J Surg Pathol,1988;12(2):134-144
19  Dougherty BG, Evans HL. Carcinoma of the anal canal: a study of 79 cases. Am J Clin Pathol,1985;83(2):159-164
20  Watanabe H, Jass JR, Sobin LH. Histological typing of esophagus and gastric tumors. World Health Organization
      International Histological Classification of Tumors. Berlin: Springer-Verlag, 1990;13-14:53-54
21  Huang ZZ, Liang YR, Wu XY. Basaloid squamous carcinoma of the esophagus: a distinctive clinicopathological entity.
      Clin J Pathol,1995;24(2):90-92(in Chinese with English abstract)
22  Abe K, Sasano H, Itakura Y, Nishira T, Mori S, Nagura H. Basaloid squamous carcinoma of the esophagus: a
 
      clinicopathologic, DNA ploidy, and immunohistochemical study of seven cases.Am J Surg Pathol,1996;20(4):453-461
23  Spiro RH, Huvos AG, Strong EW. Adenoid cystic carcinoma: factors influencing survival.Am J Surg,1977;138(5):579-583
24  Szanto PA, Luna MA, Tortoledo ME, White RA. Histologic grading of adenoid cystic carcinoma of the
 
      salivary glands.Cancer,1984;54(6):1062-1069
25  Ereno C, Lopez JI, Sanchez JM, Toledo JD. Basaloid squamous cell carcinoma of the larynx and hypopharynx:
 
      a clinicopathologic study of 7 cases. Pathol Res Pract,1994;190(2):186-193
26  Banks ER, Frierson HF Jr, Mills SE, George E, Zarbo RJ, Swanson PE. Basaloid squamous cell carcinoma of the head and 
      neck: a clinicopathologic and immunohistochemical study of 40 cases. Am J Surg Pathol, 1992;16(10):939-946
27  Klijanienko J, EI-Naggar A, Ponzio-Prion A, Marandas P, Micheau C, Caillaud JM.Basaloid squamous carcinoma of the head
      and neck: immunohistochemical comparison with adenoid cystic carcinoma and squamous cell carcinoma.
      Arch Otolaryngol Head Neck Surg, 1993;119(8):887-890
28  Seidman JD, Berman JJ, Yost BA, Iseri OA. Basaloid squamous carcinoma of the hypopharynx and larynx associated with
      second primary tumors. Cancer, 1991;68(7):1545-1549
29  Ho KJ, Herrera GA, Jones MJ, Alexander CB. Small cell carcinoma of the esophagus: evidence for a unified histogenesis.
      Hum Pathol, 1984;15(5):460-468
30  Ibrahim NBN, Briggs JC, and Corbishley CM. Extrapulmonary oat cell carcinoma.Cancer, 1984;54(8):1645-1661
31  Cheng GY, Zhang DW, Zhang LG, Wang GQ, Zhang DC, Lui XY et al. Evaluation of the new international TNM staging 
      system for carcinoma of the esophagus as compared with the Chinese trial clinicopathological staging system. An 
      analysis  of 224 cases.Chin J Oncol, 1993;15(5):358-361 (in Chinese with English abstract) 

 

Reviews Add
more>>


Related Articles:
more>>