Superficial acral fibromyxoma: a clinicopathological study of new 41 cases from the U.K.: should myxoma (NOS) and fibroma (NOS) continue as part of 21st-century reporting?

BACKGROUND: Superficial acral fibromyxoma (SAF) remains poorly recognized by general pathologists and dermatopathologists, partly attributable to its relatively uncommon occurrence and recent documentation. OBJECTIVES: To examine a series of SAF and document the U.K. experience with this new entity. METHODS: We reviewed 771 tumours reported between 1970 and 2006 in seven different U.K. hospitals and coded as myxoma, not otherwise specified (NOS), fibroma (NOS) or dermatofibroma (NOS) presenting at acral sites. Forty-one cases of SAF were studied. RESULTS: The patients comprised 27 men and 14 women, age range 19-91 years (mean 50, median 47), presenting with a solitary mass or nodule with a mean size of 1.92 cm. The common clinical sites were the toes (n=29) and fingers (n=11) as well as the palm (n=1), with more than 75% of cases close to or involving the nail bed. All cases presented with a painless mass except for four cases where pain was the presenting complaint. A history of trauma was reported in only two cases. Histologically, all cases presented as proliferation of spindle-shaped and/or stellate cells with a storiform and fascicular pattern embedded in a fibromyxoid/collagenous stroma with conspicuous mast cells. Multinucleated cells were observed (n=22), increased number of blood vessels in the stroma and extravasation of red blood cells (n=4). The characteristic immunophenotype was CD34+, CD99+/-, epithelial membrane antigen+ focally/-, S100-, desmin-, smooth muscle actin-, HMB45- and cytokeratin-. CONCLUSIONS: We describe a large series of 41 cases of SAF showing that it is a distinct entity with typical clinical, histological and immunohistochemical features. Follow-up was available only in 12 patients, precluding a firm comment on recurrence. However, complete excision and follow-up review is recommended.

Adamantinoma associated with botryomycosis: the first report of this rare association after trauma.

A 27-year-old man presented with swelling and inflammation of his right tibia, which had been present for nearly 3 years. It apparently was associated with an injury that was sustained to the right leg when it was struck against a tree stump, which had led to immediate swelling. There were no other symptoms and no history of fever or weight loss. The right tibia was swollen to twice the size of the left and the skin was indurated with numerous crusted lesions and some sinus-like areas, but no ulceration of the skin surface was apparent. We report for the first time to our knowledge a unique case of both botryomycosis and adamantinoma in the right tibia of the same patient at an area of previous trauma. Pathologists, clinicians and radiologists should be aware that both lesions can occur together. Although both botryomycosis and adamantinoma usually have a history of trauma, as in our patient, a causal relationship will need more cases to establish a possible link.