Angiomatoid Fibrous Histiocytoma Initially Misdiagnosed as Elastofibroma Dorsi: A Case Report and Literature Review

Abstract

Background and Objectives: Angiomatoid fibrous histiocytoma (AFH) is a rare soft-tissue tumor with a low-grade malignancy. It typically arises in superficial soft tissues of the extremities, head, neck and trunk in children or young adults. Because of its rare entity, it tends to be confused and misdiagnosed. Materials and Methods: A 12-year-old male presented with a painless mass located on his right upper back. The CT finding showed a 7.3 × 2.8 × 5.4 cm-sized, well-defined heterogeneous soft tissue mass in the right infrascapular area. We performed a complete excision, including the surrounding capsule. Result: The final pathology revealed an AFH of intermediate malignancy. On pathologic examination, the lesion was a 5.8 × 4.5 × 2.6 cm-sized mass with a mitotic count of 12/10 HPF, tumor necrosis of 0% and marked increased cellularity and spindle cell morphology. The immunohistochemical study showed negative for S100 and positive for SMA, focal positive for Ki-67, CD68 and positive for CD99, Desmin staining. During the five years of follow-up period, he did not show any evidence of recurrence. Conclusions: The result was satisfactory. We report a case of AFH of the back initially misdiagnosed as an elastofibroma dorsi (ED) with the review of the literature for this uncommon entity.