Angiomatoid Fibrous Histiocytoma: A Series of Three Cases

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

BACKGROUND

Angiomatoid fibrous histiocytoma (AFH) is a rare, slow-growing soft tissue tumor. It appears mostly on the limbs and trunk in children and young adults. The biology of AFH remains unclear because of the small number of reported cases. Diagnostic testing does not provide definitive results. It has two clinical forms, that differ in terms of gene expression and clinical prognosis. It is important to inform the laboratory which specific gene testing is necessary. Here, we describe a case of rare AFH in the submandibular region using a full genetic panel.

CASE SUMMARY

A 13-year-old boy who had been misdiagnosed in the past 6 mo by his dentist visited our clinic because of a lesion in the submandibular area on the right side. The lesion was homogeneous and painless upon palpation. No skin discoloration was observed. Due to the non-specific radiological picture computed tomography (CT), magnetic resonance imaging (MRI), cone-beam CT (CBCT), and ultrasound-guided biopsy were performed. A venous malformation was suspected on the MRI. None of the tests provided a definitive diagnosis. Owing to the non-specific radiological findings, the patient qualified for surgical treatment. The surgical procedure included an excisional biopsy. The diagnostic testing was extended using gene rearrangements. The most distinctive gene translocation in diagnosing AFH is within the EWS RNA-binding protein 1 (EWSR1)-CREB-binding protein. However, in this case, the diagnosis was confirmed by a rearrangement within the EWSR1 gene testing.

CONCLUSION

AFH in the submandibular location is rare, and surgical treatment with genetic evaluation defines AFH type that affects subsequent procedures.

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

Angiomatoid fibrous histiocytoma (AFH) is a rare neoplasm described for the first time by Enzinger in 1979, and classified by World Health Organization 2020 as intermediate malignant potential neoplasm. It mostly occurs in the subcutis and is characterized by varying proportions of epithelioid, ovoid and spindle cells in a nodular and syncytial growth pattern, with some hemorrhagic pseudovascular spaces. In this paper, we report the clinical case of a 62-year-old man who presented with AFH on the right arm, and relapsed three years after first surgical excision. After a further three years, the patient presented with an intramuscular localization of AFH, and 12 months after this, a pulmonary metastasis of AFH was diagnosed. Given the rarity of the spreading of AFH, we performed Fluorescence In Situ Hybridization (FISH) and we detected EWSR1::CREB1 gene fusion.