Rippled‐pattern trichoblastoma with apocrine differentiation arising in a nevus sebaceus: report of a case and review of the literature

Abstract

A 36-year-old man developed a papular growth in a portion of a nevus sebaceus on the post-auricular scalp. Excision showed typical histologic changes of nevus sebaceus including epidermal papillomatosis with reduced numbers of hair follicles as well as numerous sebaceous glands high in the dermis that focally emptied directly to the overlying epidermis. Histologic sections of the papular growth at the superior pole of the nevus sebaceus showed a proliferation of cytologically bland basaloid epithelial tumor lobules both in the superficial dermis, with multiple connections to the epidermis, and within the deeper dermis in a nodular growth pattern demonstrating papillary mesenchymal bodies. Ductal structures with apocrine-type decapitation secretion were present. There was prominent palisading of nuclei in rows parallel to one another, alternating with bands of homogenous eosinophilic stromal material forming a ripple pattern resembling the Verocay bodies of schwannoma. The histologic features resembled those of rippled-pattern trichoblastoma with apocrine differentiation arising in a nevus sebaceus, an association not previously described. We discuss this case as well as review the literature on rippled-pattern trichoblastoma.

Ripple/Carcinoid Pattern Sebaceoma With Apocrine Differentiation

“…The argument regarding whether other neoplasms, such as trichoblastomas or basal cell carcinomas, also demonstrate a ripple/carcinoid pattern is still remains controversial. 12 The absence of fibrotic stroma, of rudimentary follicular germs and papillae, and of a palisading border in the neoplastic aggregations and the presence of many vacuolated cells favor the diagnosis of sebaceoma rather than trichoblastoma in the presented case with a ripple/carcinoid pattern. 2 Another interesting finding of the present case is the observation of apocrine glandular structures within the sebaceoma lesion, and this kind of rare observation has also recently been reported.…”

“…In addition, no cases of sebaceomas with a ripple/carcinoid pattern and apocrine differentiation have previously been reported to be associated with Muir-Torre Syndrome. [1][2][3][4][5][6][7][8][9][10][11][12] …”

Central Nuclear Palisading in Nodular Basal Cell Carcinoma: Morphological and Immunohisto­chemical Concerns

“…Verocay-like bodies are also found in other epithelial neoplasms, such as rippled-pattern trichoblastoma (7) and sebaceoma (8); however, the absence of peripheral stromal structures, such as papillary mesenchymal bodies and fibrocellular stroma, makes it difficult to distinguish these neoplasms from BCC with Verocay bodies without additional studies: CK-20 immunoreactive cells and scattered sebaceous cells are useful findings to distinguish trichoblastoma and sebaceoma, respectively, from BCC.…”

Infundibulocystic Structures and Prominent Squamous Metaplasia in Sebaceoma—A Rare Feature. A Clinicopathologic Study of 10 Cases

“…[10][11][12] In this study, we describe a rare and underrecognized feature in sebaceoma, namely numerous infundibulocystic structures, occurring alone or in combination with squamous metaplasia. When unduly prominent, this feature may represent a diagnostic pitfall in a limited biopsy specimen.…”