Case Series of Angiomatoid Fibrous Histiocytoma (AFH)-A Clinico-Radiological and Pathological Conundrum

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor, common in children and young adults, often misdiagnosed as either reactive or malignant. This study aims to highlight the clinico-radiological and pathological features of this uncommon entity. Eighteen cases of AFH diagnosed over a period of 20 years were analyzed and correlated with clinical data. The tumor had a wide age distribution with an M:F ratio of 3.5:1. Though swelling was the common clinical presentation, a subset of patients had constitutional symptoms like fever, weight loss, loss of appetite, and anemia. One patient was referred with deranged aPTT and hypergammaglobulinemia. The radiological features were also myriad ranging from infection in a discharging soft tissue swelling to lymphoma (in cases with nodal involvement) to sarcoma (angiosarcoma and telangiectatic osteosarcoma). Sites of occurrence were soft tissue of the upper limb, lower limb, head and neck, bone, and lung. Intra-operatively, these tumors run the risk of bleeding and may require pre-op embolization and support by blood and blood products. Wide local excision was the primary treatment offered. Macroscopically, the average size was 3.5 cm; the cut surface was nodular, cystic with hemorrhage, and gray-white to brownish-yellow in color. Microscopically, the tumors were circumscribed with a fibrous pseudo-capsule and showed mildly pleomorphic spindle cells insheets and fascicles, in a sclerotic to myxoid stroma. A peripheral cuff of lymphoplasmacytic cells was present in all cases. Atypical histological features observed were moderate nuclear pleomorphism, frequent mitosis, solid variant, and myxoid stroma. Immunohistochemically, they were most often positive for desmin, CD68, and EMA. Interestingly, about 55.5% cases had lymphadenopathy of which three showed metastatic tumor. Three of our cases harbored EWSR1 re-arrangement, proven by FISH. Follow up details were available for six patients and none showed recurrence. In conclusion, we emphasize the importance of improved recognition of this rare yet morphologically distinct neoplasm, with varied clinico-radiological presentation.