Epstein-Barr virus-associated smooth muscle tumors in immunocompromised patients: Six case reports

Table 1 Demographic characteristics and clinical summary of six Epstein-Barr virus associated smooth muscle tumor at a major quarternary care hospital

Cases	Sex	Type of transplant/IS	IS	Age at transplant (yr)	Age at diagnosis (yr)	EBV titer at diagnosis (copies per mL)	Tumor location	Histopathology findings	Treatment	Outcome (years post EBV-SMT)	Follow up
1	F	OHT	Tacrolimus	8 mo	6	286000	Colon	Smooth muscle spindle cell proliferation with strongly positive in-situ EBER hybridization and focal desmin+	Tacrolimus reduced	Alive (age 16)	None
2	M	OHT	Tacrolimus, MMF	17	20	161476	Thymus, lung, liver, mesenteric, and retroperitoneal lymph nodes, ascending colon, and proximal left femoral bone marrow	The spindled cells were positive with antibodies to smooth muscle antigen and desmin. Tumor cells were focally positive with antibodies to caldesmon. The spindle cells were negative with antibodies to S100 protein and cytokeratin AE1/3. In situ hybridization revealed that up to 80% of tumor cell nuclei were positive for the presence of EBER	Supportive	Death (age 20)	NA
3	F	OHT	Tacrolimus; Sirolimus	12	16	11848	Brain, lung, kidney	Hepatic parenchyma focally replaced by spindle cell proliferation. The spindle cells are arranged in a haphazard pattern and contain nuclei with minimal nuclear pleomorphism and abundant eosinophilic cytoplasm. (1) The tumor cells are strongly positive for h-caldesmon and smooth muscle actin; (2) Desmin+; (3) EBER positive by CISH; (4) CD20+, MUM-1+. CD3-, CD10-. EBER ISH+ (CNS); and (5) H-caldesmon+, smooth muscle actin+, desmin+ (focal). EBER ISH+ (liver)	Intrathecal rituximab, methotrexate, systemic chemotherapy, whole brain radiation, and T-cell therapy	Alive (age 22); course c/b seizures	Yearly brain and liver MRI
4	M	OHT/OLT	Tacrolimus	58	61	25458	Kidney, liver, lung	(1) Monotonous proliferative of relatively uniform spindle cells arranged in intersecting fascicles with pale eosinophilic cytoplasm and elongated, blunt-ended nuclei with dark vesicular chromatin.; (2) Mitotic figures are not readily identified and there is no significant cytologic atypia, pleomorphism, or necrosis; (3) The tumor cells are strongly immunoreactive for SMA and negative for CD117, DOG-1, desmin, S100, SOX10, CD34, and STAT6; and (4) EBER positive by CISH	L lateral segmentectomy w superficial wedge resection;Tacrolimus reduced, stopped, and eventually started given concern for ACR	Death (age 61)	NA
5	M	LRD kidney	Prednisone, MMF, Sirolimus	55	63	4765	Liver	(1) Fascicles of malignant appearing spindle cells diffusely positive for desmin and H-caldesmon; and (2) EBER positive by CISH	MMF. Sirolimus dosing decreased	Alive (age 73)	Repeat MRI with stable/decreased size hepatic lesions; no new lesions noticed
6	F	HIV	Abacavir-Lamivudine-Dolutegravir for HIV	NA	45	NA	Thoracic spine	(1) Spindle cell neoplasm staining positive for smooth muscle actin; (2) Negative for desmin; and (3) EBV positive by CISH	s/p T8-T10 Laminectomy; no change in HAART	Alive (age 55); total hip arthroplasty for bl avascular necrosis	None

IS: Immunosuppressant; EBV: Epstein-Barr virus; EBER: EBV-encoded small RNA; MRI: Magnetic resonance imaging; F: Female; M: Male; OHT: Orthotopic heart transplant; MMF: Mycophenolate mofetil; NA: Not available; OHT/OLT: Combined orthotopic heart and liver transplant; LRD: Living related donor; HIV: Human immunodeficiency virus.