Firstly, discribed in 2001. Cylindroma of the breast is such a rare entity, for only 9 cases were published in the literature [1
]. Cylindromas presented in five cases as symptomatic masses, in one case as a lesion at mammography, and in three cases as incidental findings in excisions performed for invasive carcinoma; ductal type in two cases and lobular type in another. Six cases arose in the left breast and three in the right breast. In three cases the cylindromas were retroareolar, and in five cases they arose adjacent to lactiferous ducts. Our case had neither of these features. Two cases were associated with familial cylindromatosis. All cases were treated with excision except one patient with an infiltrative ductal carcinoma who had a mastectomy. Two patients who also had an infiltrating carcinoma underwent axillary dissection which showed metastatic breast carcinoma to lymph nodes but no involvement by cylindroma. None of eight patients had recurrence with follow-up ranging from six months to five years. One patient was lost to follow up. All lesions were identical in morphological appearance to dermal cylindromas. They consist of nests and trabeculae of cells that interlock in a "jigsaw" or "mosaic" pattern. The nests are composed of peripheral basaloid cells, central larger cells with oval vesicular nuclei, occasional clusters of sebaceous cells and squamous cells, and scattered reactive langerhans cells. A markedly thickened basement hyaline membrane, which is immunoreactive to collagen IV, and PAS surrounds the epithelial nests. Hyaline globules, composed of basement membrane material, are focally present within the epithelial nests. Focal eccrine ducts are present and may contain secretions. Diffuse positivity for p63 in the basaloid cells and CK7-positivity in the larger central cells support the morphological impression of two divergent types of cellular differentiation; myoepithelial and ductal. The extent of positive nuclear staining for p63 supports predominant myoepithelial differentiation in these tumors. Breast cylindromas occur entirely within the breast parenchyma with no connection to the overlying skin.
Dermal cylindromas are relatively common benign skin adnexal neoplasms. They usually occur in the sixth decade of life, with a male preponderance of 1:9. They present most commonly on the head, neck, or scalp as slowly growing, pink to purple, solitary or multiple, smooth surfaced nodules, which can rarely grow and coalesce to produce the characteristic turban-like mass (turban tumor). Most are asymptomatic but they can be painful when associated with spiradenoma. Although morphologically identical one study suggested that dermal cylindromas as a group may have more langerhans cells and eccrine ducts than breast cylindromas [3
]. Cylindromas have also been reported at other extracutaneous sites including salivary gland, bronchus, lung and kidney. Brooke-Spiegler syndrome or familial cylindromatosis is a rare familial condition, which is inherited in an autosomal dominant fashion, with variable expression and penetrance. The syndrome is associated with the occurrence, generally from childhood or adolescence, of multiple dermal cylindromas. The lesions are widely distributed not only on the head and neck, but also the trunk and extremities, and are occasionally associated with other dermal adnexal tumours such as spiradenoma [5
In two of the nine published cases of breast cylindroma the patients had Brooke-Spiegler syndrome. The CYLD gene, which is responsible for this syndrome, has been localized to chromosome 16q12-q13, and probably represents a tumour suppressor gene [6
]. Malignant transformation of dermal cylindromas is very rare but cases have been reported in the setting of Brooke-Spiegler syndrome. Malignant cylindromas often present with ulceration of the skin and display large epithelial cells with marked pleomorphism, numerous mitotic figures and obvious invasion, but usually there is a transition from benign to malignant [7
A variety of neoplasms of eccrine and apocrine sweat glands have been reported in the breast. Their occurrence at this site is not surprising as the breast is an ectodermal derivative of the same cell lineage that gives rise to the cutaneous apocrine glands. In fact, many authors regard the breast as a modified sweat gland. The most common adnexal tumors occurring in the breast are mixed adnexal tumour and syringoma, which follow a benign clinical course in most cases. However cases of recurrent spiradenoma [8
] and a carcinomasarcomatous eccrine spiradenoma [9
] have been reported.
Cylindroma of the breast has been linked with the solid type of adenoid cystic carcinoma (ACC), basaloid variant in the literature. Morphologically, both tumours have a nodular and trabecular appearance, they also share basaloid cells, myoepithelial cells. Moreover, eccrine ducts structure and hyaline globules of basement membrane have been recognised in both tumours. Solid-type ACC can display moderate to marked nuclear atypia, invasive tumor borders, and brisk mitotic activity [10
]. However, Cylindroma of the breast does not exhibit nuclear atypia or mitoses. ACC may be associated with mucin production, a feature which is not present in cylindroma. Recently, it has been reported that mammary ACC expresses c-kit in the luminal component [11
]. However, in our case, the tumour nests didn't express any type of positivity for c-kit except for few mast cells present within the intervening stroma. While the two entities share a basal membrane that surrounds the cell nest, immunohistochemical stains for the collagen IV material reveals a thin, discontinuous band of membrane surrounding the nodules of ACC [12
], in contrast to a thickened, continuous band of basement membrane that surrounds the epithelial nests of breast cylindromas. Although mammary ACC has an excellent prognosis, yet there have been reported cases with local recurrence and distant metastases [13
]. The basaloid, solid-variant ACC runs an aggressive clinical course; it has been reported to metastasize to axillary lymph nodes [14
]. On the other hand, breast cylindroma characteristically runs a completely benign course. All previous cases reported in the literature have been treated with wide local excision, have not recurred and have not metastasized to lymph nodes or to distant organs. Furthermore, mastectomy or excisional biopsy with adjuvant radiotherapy has been recommended as treatment of solid-variant of mammary ACC [10