Diffuse large B-cell Lymphoma (DLBCL) is a heterogeneous group of malignant tumors with diverse prognoses, histological appearances, and clinical symptoms. While it commonly affects lymphoid tissues, its occurrence in the nasal cavity and paranasal sinuses is rare and poses significant diagnostic challenges.

The authors present a case of a 53-year-old man with a history of testicular non-Hodgkin lymphoma treated 5 months prior. He presented with symptoms initially misdiagnosed as a dental abscess, which was later identified as DLBCL in the maxillary sinus.

The etiology of primary lymphoma in the oral region remains unclear. Due to its rarity, specific prognostic factors, and optimal treatment strategies are not well-established. This case highlights the diagnostic challenges and underscores the importance of considering lymphoma in the differential diagnosis of nonresponsive dental abscesses.

This case underscores the importance of thorough investigation in patients with nonresponsive dental abscesses. Early identification and appropriate management of DLBCL in uncommon sites require heightened clinical awareness and interdisciplinary collaboration. The optimal treatment approach remains debated and warrants further research.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma (ML), accounting for 30%-40% of cases of non-Hodgkin's lymphoma (NHL) in adults. Primary paranasal sinus lymphoma is a rare presentation of extranodal NHL that accounts for only 0.17% of all lymphomas. ML from the maxillary sinus (MS) is a particularly rare presentation, and is thus often difficult to diagnose. We have reported the first known case of DLBCL originating from the MS with rapidly occurrent multiple skin metastasis.

An 81-year-old Japanese man visited our hospital due to continuous pain for 12 d in the left maxillary nerve area. His medical history included splenectomy due to a traffic injury, an old right cerebral infarction from when he was 74-years-old, hypertension, and type 2 diabetes mellitus. A plain head computed tomography (CT) scan revealed a 3 cm × 3.1 cm × 3 cm sized left MS. On day 25, left diplopia and ptosis occurred, and a follow-up CT on day 31 revealed the growth of the left MS mass. Based on an MS biopsy on day 50, we established a definitive diagnosis of DLBCL, non-germinal center B-cell-like originating from the left MS. The patient was admitted on day 62 due to rapid deterioration of his condition, and a plain CT scan revealed the further growth of the left MS mass, as well as multiple systemic metastasis, including of the skin. A skin biopsy on day 70 was found to be the same as that of the left MS mass. We notified the patient and his family of the disease, and they opted for palliative care, considering on his condition and age. The patient died on day 80.

This case suggests the need for careful, detailed examination, and for careful follow-up, when encountering patients presenting with a mass.

Orbital lymphomas constitute 50-60% of ocular adnexal lymphomas. A total of 2211 cases of orbital lymphoma with a known subtype have been reported in the last 24 years (1994-2017). The vast majority of orbital lymphomas are of B-cell origin (97%), of which extranodal marginal zone B-cell lymphoma (EMZL) (59%) is the most common subtype, followed by diffuse large B-cell lymphoma (23%), follicular lymphoma (9%), and mantle cell lymphoma (5%). Orbital lymphoma is primarily a disease of the elderly. Gender distribution varies according to lymphoma subtype. However, extranodal marginal zone B-cell lymphoma (53%) and follicular lymphoma (75%) show a female predominance, whereas diffuse large B-cell lymphoma shows an even gender distribution. Mantle cell lymphoma has a striking male predominance of 80%. The histopathological subtype and the clinical stage of the disease are the best indicators of prognosis and patient outcome. Low-grade lymphomas such as extranodal marginal zone B-cell lymphoma and FL have a good prognosis, whereas high-grade lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) are associated with a poor prognosis. When managing solitary low-grade lymphomas, radiotherapy is the treatment of choice. Chemotherapy, with or without radiotherapy, should be chosen for disseminated and high-grade lymphomas.

Lymphomas frequently occur as extranodal lesions in the head and neck, but are rarely seen in the palate. We present a case of isolated diffuse type B-cell lymphoma of the palate, which occurred in a 28-year-old man. The patient had no history of immune compromise, and he presented to the emergency department with a 7-month history of a painful, non-healing ulcerative mass in the hard and soft palate. Positron emission tomography facilitated pretreatment assessment of the extent and activity of the lesion. Histopathological and immunohistochemical analyses of biopsied tissue confirmed a diagnosis of diffuse type B-cell lymphoma. The clinical findings and therapeutic challenges in this heterogeneous group of malignancies are discussed.

Non-Hodgkin's lymphoma (NHL) constitutes a group of malignancies those arises from cellular components of lymphoid or extranodal tissues. The head and neck is the most common area for the presentation of these lymphoproliferative disorders. Primary involvement of salivary glands is uncommon. This report described a case of a 73-year-old female patient who presented with involvement of both nodal and extranodal sites, with predominant involvement of salivary glands. The tumor staging worked up along with imaging, histopathological, and immunohistochemical findings were discussed. Computed tomographic images showed the involvement of Waldeyer's ring, larynx, orbit, and spleen. This report described imaging and prognostic tumor markers in diagnosing, treatment planning, and prognosis.