Angiomatoid Fibrous Histiocytoma of the Neck Mimicking a Large Nodal Metastatic Carcinoma: A Rare Tumour at an Unusual Site

Aims: Angiomatoid fibrous histiocytoma, a tumour of uncertain differentiation and intermediate behaviour, is rarely seen in the head and neck region. We report its dramatic presentation in the neck as a progressive, large mass mimicking malignancy clinically as well as cytologically, to share our challenges in diagnosing and treating this condition.

Presentation of Case: A healthy 40-year-old gentleman presented to our centre with a 2-year history of a slowly progressive large right neck mass, without any constitutional symptoms. Examination showed a large right neck mass and subsequent fine needle aspiration revealed metastatic carcinoma. Loss in follow up, he returned 2 years later without any progression. This unusual behaviour raised suspicion and subsequent incisional biopsy revealed a spindle cell neoplasm suggestive of a sarcoma. Excision of the lesion showed a well-encapsulated tumour, and subsequent histopathological examination revealed an angiomatoid fibrous histiocytoma of the neck.

Discussion: Angiomatoid fibrous histiocytoma presents a diagnostic dilemma to clinicians as: clinically, it may display similar appearance to a lipoma, haematoma or haemangioma and pathological examination of the lesion may mimic metastatic carcinoma or melanoma, even in the presence of distinctive morphology. The mainstay of treatment is surgical excision and in the rare case of recurrence or metastasis; chemoradiotherapy.

Conclusion: A slowly progressive neck mass reported as metastatic carcinoma should be investigated with caution.