Trichoblastoma, syringocystadenoma papilliferum, desmoplastic trichilemmoma and tumor of the follicular infundibulum with signet‐ring cells, all arising in nevus sebaceus

Abstract

Herein, we describe a 63-year-old male with multiple tumors arising within a nevus sebaceus on the posterior scalp. On histopathologic examination, four distinct tumors were identified: trichoblastoma, syringocystadenoma papilliferum, desmoplastic trichilemmoma and tumor of the follicular infundibulum (TFI). Within the TFI component of the nevus sebaceus, there was intracytoplasmic accumulation of eosinophilic keratin, as shown on pancytokeratin-stained sections, imparting a signet-ring appearance to the cells. To our knowledge, this is the first report of signet-ring cells arising within a TFI occurring in a nevus sebaceus. We discuss this case as well as review the literature on multiple tumors arising within nevus sebaceus and signet-ring cell changes in primary cutaneous tumors.

Desmoplastic trichilemmoma of the scalp: case report and literature review of immunohistochemical staining features

“…7 However, sometimes DT develops from nevus sebaceous. 5,[13][14][15] DT can develop concomitantly with a variety of other adnexal tumors, such as trichoblastoma; 5 it also may occur in combination with basal cell carcinoma (BCC). 11,15,16 Histologically, a DT lesion is lobulated with a clear boundary that extends into the dermis and is continuous with the epidermis.…”

Development of seven secondary neoplasms in a nevus sebaceous: a case report and literature review

“…DT is an uncommon histological subtype of trichilemmoma, and only 10 cases of DT arising within NSJ have been described [ 8 , 11 , 15 , 16 ]. Histopathologically, DT presents as a well-defined lobular tumor with typical features of trichilemmoma at the periphery and a central desmoplastic stroma.…”

Tumor of follicular infundibulum–associated neoplasms

“…Since the discovery of TFI in 1961, there have been many accounts of associated neoplasms ( Table I ). 9 , 13 , 14 , 15 , 16 , 17 , 19 , 20 , 21 One of the first mentions of TFI-associated lesions was in 1989, by Kossard et al. 6 In studying eruptive infundibulomas, they found that the platelike epithelial architecture of TFI was seen in association with seborrheic keratoses and BCC.…”