Histiocytic Sarcoma : Clinical Features

Comments:
Clinical Features of Histiocytic Sarcomas: Patients are usually adults and present with systemic symptoms, including fever, fatigue, weight loss, and generalized weakness. Physical examination may show lymphadenopathy (most frequently cervical), hepatosplenomegaly, or skin lesions (rash-like eruption or solitary/multiple lesions on trunk and extremities). Gastrointestinal involvement can result in GI bleeding and intestinal obstruction. Radiography may show lytic bone lesions.

Case History: The patient was a 43 y/o male who presented with fatigue, anemia, weight loss, abdominal pain, and upper gastrointestinal bleeding. On endoscopy, there was a large gastric mass bulging into the lumen. Imaging studies showed several enlarged lymph node groups (retroperitoneal, axillary, and mediastinal). Patient underwent partial gastrectomy.

Gross specimen showed an ulcerated 15 cm tumor in the stomach wall extending from mucosa to serosal surface. Sections showed sheets of highly pleomorphic epithelioid tumor cells with abundant eosinophilic cytoplasm. The nuclei were hyperchromatic and irregularly shaped with grooves and folds.

Immunohistochemical profile: The tumor was strongly positive for CD68, CD163, and CD4; focally positive for S-100 and CD31; negative for CD20, CD79a, CD2, CD3, CD7, CD8, CD43, CD56, CD1a (Langerin), cytokeratin, and EMA. The Ki-67 proliferation index was 50%.