BACKGROUND: Familial cylindromatosis is a rare genetic disorder, giving rise to neoplasms of the skin appendages. We have recently shown that loss of the cylindromatosis tumour suppressor gene leads to activation of NF-kappaB, a transcription factor having antiapoptotic activity. This provides a possible explanation for the deregulated growth of cylindromas. In cell-based assays, salicylate can prevent NF-kappaB activation caused by loss of the cylindromatosis gene, suggesting that salicylic acid application might be a potential treatment for cylindromatosis. OBJECTIVES: To assess the effectiveness of topical application of salicylic acid on familial cylindromas. METHODS: Cylindromas in five patients from four different cylindromatosis families were treated with twice daily and then once daily topical salicylic acid. Clinical response was determined by serial tumour measurements. RESULTS: In total 17 cylindromas in five patients were studied: 12 target lesions and five control lesions. The median size of the cylindromas was 1.0 cm (range, 0.6-2.8 cm). Two of the 12 cylindromas showed a complete remission. Another eight lesions showed some response, but not sufficient to qualify as partial remission. The control lesions remained stable or increased in size. CONCLUSIONS: Salicylic acid is a well-tolerated and potential new treatment for cylindromatosis.

Cylindroma (dermal analog tumor) of the breast: a comparison with cylindroma of the skin and adenoid cystic carcinoma of the breast. Am J Clin Pathol. 2005 Jun;123(6):866-73.

We compared 4 breast cylindromas with 50 dermal cylindromas and 8 adenoid cystic breast carcinomas. Except for a modest increase in the number of eccrine ducts and reactive Langerhans cells in dermal cylindromas, breast and dermal cylindromas showed identical histologic and immunohistochemical features. Both were characterized by epithelial islands containing central basaloid cells and peripheral myoepithelial cells surrounded by a thickened, continuous, periodic acid-Schiff-positive basement membrane that was immunoreactive for collagen IV. Clusters of sebaceous cells and a few eccrine ducts are described in breast cylindromas. Cytokeratin 7 labeled predominantly the central basaloid cells, and smooth muscle actin stained peripheral myoepithelial cells in breast and dermal cylindromas. Eccrine ducts were highlighted by epithelial membrane antigen and carcinoembryonic antigen. S-100 protein and CD1a showed a variable number of dendritic Langerhans cells. Cylindromas of the breast and skin did not express cytokeratin 20, gross cystic disease fluid protein 15, or estrogen or progesterone receptor. Breast cylindroma might be confused with the solid variant of adenoid cystic carcinoma, especially in needle core biopsy specimens, because they share nodular and trabecular patterns, basaloid cells, myoepithelial cells, eccrine ducts, and hyaline globules of basement membrane material. However, adenoid cystic carcinoma displays an infiltrative growth pattern, cytologic atypia, and mitotic figures and lacks the continuous, thickened basement membrane.