Angiomatoid Fibrous Histiocytoma: A Tumor With Uncertain Behavior and Various Clinicopathological Presentations

Abstract

BackgroundAngiomatoid fibrous histiocytoma (AFH) is a rare soft tissue neoplasm of uncertain differentiation, which has various clinical and morphological presentations. Although it behaves in a benign manner, it has malignant potential. AimTo share various histological patterns and survival data in our population of this rare entity. Materials and methodsWe studied 25 patients who reported AFH from January 2011 to December 2021. Clinical information, gross and histological features, immunohistochemical results, and survival data were compiled and analyzed. ResultsAmong 25 cases reported as AFH, the majority (68%) were males with a mean age of 31.8 years at the time of diagnosis. The most common location was the lower extremity, especially the thigh (56%), and the mean size of the lesion was 55 mm. Most of the lesions were superficial (84%). Grossly, the majority of lesions (76%) had a solid appearance. Microscopically, classic spindle cell morphology was the most common (76%) with a lymphoid cuff and intralesional hemorrhage. Mild cellular atypia was seen in most (92%) of the cases, while some biopsies (8%) had a high-grade morphology. The majority of patients were alive, while one patient died of the disease. ConclusionAFH is an under-recognized entity with various clinical and histological presentations and a low malignant potential.

A case of pulmonary artery tumor easily confused with chronic thromboembolic pulmonary hypertension

“…AFH is a spindle cell mesenchymal tumor with uncertain origin and invasive soft tissue tumor, belonging to intermediate type/borderline type or tumor with uncertain malignant potential and uncertain direction of soft tissue differentiation [2]. AFH tends to occur in the body, head, and neck soft tissue, and extrasomatic AFH is very rare [4]. The main treatment for AFH is complete surgical resection without postoperative radiotherapy and chemotherapy, with a small recurrence rate (2%-11%) and metastasis rate < 1% [1,2].…”

Difficulties in diagnosing angiomatoid fibrous histiocytoma of the head and neck region: A case report

“…The tumor growth is slow and painless. Patients are often unaware of this disease[ 2 ]. This may be accompanied by fever and general weakness.…”

“…Based on immunohistochemistry results, CD68, CD99, EMA, and wimentyne (EP21) were positive for epithelial membrane antigens, whereas cytokeratin and S100 protein were negative[ 5 , 11 , 12 ]. However, desmine was positive and negative in two different assays[ 2 , 5 , 12 ].…”

“…It was first described in 1979 as “angiomatoid malignant fibrous histiocytoma” and it was classified by the World Health Organization under the category of “tumors of uncertain differentiation” in 2020. AFH is a lesion that rarely metastasizes[ 2 - 4 ]. It mostly occurs on the superficial extremities of both children and young adults[ 3 , 5 - 7 ].…”

Angiomatoid Fibrous Histiocytoma (AFH) of the Right Arm: An Exceptional Case with Pulmonary Metastasis and Confirmatory EWSR1::CREB1 Translocation

“…Regarding the differential diagnosis, it is important to differentiate AFH from other types of dermatofibroma, or, in the case of prominent myxoid change, from other myxoid tumors such as low-grade fibromyxoid sarcoma, extraskeletal myxoid chondrosarcoma and myxoid liposarcoma [ 4 ]. The case presented is of particular interest for three reasons: (1) AFH metastasis rate described in the literature is around 1–5%, with about 15 cases of AFH lung involvement described [ 5 , 6 ]; (2) from the few published cases of metastatic AFH, it would seem that the presence of the EWSR1::CREB1 fusion gene predisposes more aggressive behavior of the neoplasm [ 7 ]; careful follow-up with the possibility of performing a FISH in cases of relapsed AFH is mandatory [ 1 , 2 , 8 , 9 , 10 , 11 , 12 ].…”