A systematic review of Pilomatrix carcinoma arising from the previous scar site of Pilomatrixoma

Abstract

ABSTRACT Pilomatrix carcinoma is a rare tumor arising from the hair follicle matrix cells most commonly seen in the head and neck region. Also known as “calcified epithelial carcinoma of Melherbe,” it was first reported in 1980 by Lopansri and Mihm. Since then till date to the best of our knowledge only around 125 cases were reported in literature, of which only 11 cases were reported to arise from histologically proven areas of previous pilomatrixoma which is the benign variant. One such case is being reported here along with the review of literature. A 50-year-old man presented with a swelling in the nape of his neck since 6 months, which was gradually increasing in size. He had a history of similar swelling at the same site 18 months back for which he underwent a surgery at a center outside. Final histopathology report was suggestive of pilomatrixoma with negative margin. Wide local excision of the tumor with 3 cm margin, placement of surgical clips followed by a primary closure was done. The final histopathology report is suggestive of pilomatrix carcinoma. The patient has no recurrence in 6 months follow-up. The differential diagnosis of pilomatrix carcinoma should be considered in cases of recurrent skin tumors. Wide local excision is the preferred treatment. Re-excision should be done in margin positive cases and cases where simple excision was done due to improper preoperative diagnosis. Due to the rarity of the disease, adjuvant treatment is not properly defined.