Angiomatoid fibrous histiocytoma: unusual sites and unusual morphology

Abstract

Angiomatoid fibrous histiocytoma is a soft tissue neoplasm of low malignant potential, typically occurring in the superficial soft tissues of the extremities in children and young adults. Occurrence outside somatic soft tissues is most uncommon. This report describes eight such cases, involving the lung (three cases), mediastinum (one case), vulva (two cases), retroperitoneum (one case) and ovary (one case), with the latter three locations being hitherto unreported sites of occurrence. Patients had a median age of 48 years, and presented with symptoms related to the mass lesion (five cases) or were incidentally found to harbor a tumor (three cases). Besides the typical histological features such as an outer shell of lymphoid tissue, multinodular aggregates of dendritic-like tumor cells, blood-filled spaces and abundant admixed plasma cells, unusual features were found focally in some cases, including clear cells, rhabdomyoblast-like cells, pulmonary edema-like pattern and tumor cell cords lying in a myxoid stroma. Immunoreactivity for the epithelial membrane antigen, desmin, smooth-muscle actin, CD68 and CD99 was found in 100, 63, 43, 100 and 100% of cases, respectively. Molecular studies provided support for the diagnosis in all seven tested cases-EWS gene translocation in six cases (partner gene being CREB1 in three and ATF1 in two in which information was available) and FUS gene translocation in one case. Comparison of the reported cases of extrasomatic angiomatoid fibrous histiocytoma with their somatic soft tissue counterparts showed a number of differences: higher mean age, slight male predominance (particularly for bone lesions), larger tumors, higher frequency of systemic symptoms, higher recurrence rate, myxoid change being more common and a much higher frequency of EWS/ATF1 gene fusion.

Angiomatoid Fibrous Histiocytoma: The Current Status of Pathology and Genetics

“…9,10 Extrasomatic AFHs also show a higher mean age at presentation (35 years compared with 12-18 years for somatic cases) 6 and tend to be larger neoplasms. 6 Some patients experience systemic symptoms such as pyrexia, anemia, and malaise, 11 suggesting tumoral cytokine production, and this is also thought to be more frequent in extrasomatic AFH. 6 Angiomatoid fibrous histiocytoma does not have a proven relationship with any other specific conditions, although one case has been reported on the knee of a child with human immunodeficiency virus.…”

“…15 It is unclear whether these might have occurred secondarily to treatment, although it appears more likely that they were incidental. Other examples of AFH associated with other neoplasms include a vulval lesion detected at the same time as endometrial and ovarian carcinoma 6 and a mediastinal lesion detected during surveillance computed tomography scan for nasopharyngeal carcinoma treated with radiation therapy 13 years previously. 6 Most AFHs behave relatively indolently, with local recurrence in up to 15% of cases.…”

“…6 Some patients experience systemic symptoms such as pyrexia, anemia, and malaise, 11 suggesting tumoral cytokine production, and this is also thought to be more frequent in extrasomatic AFH. 6 Angiomatoid fibrous histiocytoma does not have a proven relationship with any other specific conditions, although one case has been reported on the knee of a child with human immunodeficiency virus. 12 Reports of its occurrence as a second neoplasm in other malignancies are rare and include a supraclavicular AFH occurring in a 27-year-old man 16 months after chemotherapy for disseminated testicular cancer, 13 an inguinal mass in a child with stage III retroperitoneal neuroblastoma, 14 and in an 18-year-old woman with a 4-year history of treatment for Hodgkin lymphoma.…”

“…1 Lesions can also present with symptoms related to the anatomic site or may be detected incidentally. 6 Other more frequent sites for AFHs are the trunk and head and neck; occurrence in nonsomatic soft tissue sites is rare but increasingly documented, and unusual primary sites include the brain, 7,8 lungs, 7-9 mediastinum, 6,9,10 retroperitoneum, 6 omentum, 11 ovary, 6 vulva, 6 and bone. 9,10 Extrasomatic AFHs also show a higher mean age at presentation (35 years compared with 12-18 years for somatic cases) 6 and tend to be larger neoplasms.…”

“…6 Other more frequent sites for AFHs are the trunk and head and neck; occurrence in nonsomatic soft tissue sites is rare but increasingly documented, and unusual primary sites include the brain, 7,8 lungs, 7-9 mediastinum, 6,9,10 retroperitoneum, 6 omentum, 11 ovary, 6 vulva, 6 and bone. 9,10 Extrasomatic AFHs also show a higher mean age at presentation (35 years compared with 12-18 years for somatic cases) 6 and tend to be larger neoplasms. 6 Some patients experience systemic symptoms such as pyrexia, anemia, and malaise, 11 suggesting tumoral cytokine production, and this is also thought to be more frequent in extrasomatic AFH.…”