BACKGROUND

Angiomatoid fibrous histiocytoma (AFH) is a slowly progressing rare soft-tissue tumour of moderate malignant potential. It is most commonly seen in children and young adults. Clinically, the lesion is easily confused with a haematoma or soft-tissue haemangioma, and the radiological aspects are not specific.

METHODS

A 16-year-old male patient presented with a nodular lesion situated very close to the right radial artery, vein and nerve and which had been developing for several years. Surgical resection was carried out with sparing of vasculonervous and functional structures. Histological examination revealed a tumour of plurinodular architecture, surrounded by a fibrous pseudocapsule consisting of histiocytoid or fusiform cells in short bundles associated with a mononuclear inflammatory reaction of nodular architecture. The tumour cells expressed the following immunomarkers: desmin, smooth muscle actin, CD99, and epithelial membrane antigen. Fusion transcript EWSR1-ATF1 was found.

CONCLUSIONS

In this case, as occurs in the literature, a diagnosis of AFH was not made on clinical examination or imaging. The enlarged excision normally recommended was greatly restricted in our patient due to the complex localization of the lesion, which was in contact with major anatomical structures. The diagnosis was based on histological examination of the surgical excision and identification of the fusion gene. Long-term follow-up is required to detect local recurrence or metastasis. Management is decided in multidisciplinary meetings.