Recurrent atypical fibroxanthoma with satellite metastasis.

Atypical fibroxanthoma (AFX) is a cutaneous neoplasm of uncertain etiology that develops on sun-exposed regions of elderly males. It is widely considered to act indolently, despite its highly malignant cytologic features. Reports of metastatic AFX are very rare, and recurrence is uncommon. We report a case of recurrent AFX exhibiting a pattern of satellite metastasis followed by evidence of regional lymph node metastasis. A 76-year-old male with prior occupational and therapeutic radiation exposure and numerous squamous cell carcinomas had AFX of the left vertex scalp limited to the dermis completely removed by micrographic surgery. Twenty months later, multiple lesions appeared at the site of previous surgery. Imaging revealed no metastases or calvarial involvement. Wide local excision showed multiple well-defined nodules involving dermis and subcutis. The primary and recurrent neoplasms were similar and composed of pleomorphic epithelioid and spindled cells with marked nuclear atypia, hyperchromasia and mitotic activity. Immunohistochemistry was positive for CD10, procollagen1 and vimentin and negative for cytokeratins AE1/AE3, cytokeratins 5/6, 34βE12, MNF116, p63 CD31, Mart1, smooth muscle actin, desmin, S100 and CD34. Forty-eight months after removal of the primary, left intraparotid and posterior triangle lymph nodes are suspected to be involved by metastasis using clinical and positron emission tomography/ computed tomography examinations.