Verruciform xanthoma overlying inflammatory linear verrucous epidermal nevus and in broad segmental distribution.

A 17-year-old woman presented with moderately itchy, non-progressive, linearly arranged verrucous plaques over dorsum of left foot since early childhood. Two years ago, she developed slowly increasing, verrucous exophytic growth in posterior most aspect of linear verrucous plaque. One year ago, she also developed multiple, linearly arranged, fleshy plaques with surface crusting over lateral aspect of right leg extending to thigh. Biopsy from both verrucous lesion on left foot and fleshy plaque on right leg showed an exophytic growth with significant papillomatosis, neutrophils in stratum corneum, acanthosis and infiltration of papillary dermis with foamy macrophages that were CD 68 positive, features compatible with verruciform xanthoma (VX). Biopsy from linear verrucous plaque over left foot was consistent with inflammatory linear verrucous epidermal nevus (ILVEN). A diagnosis of segmental VX and VX overlying ILVEN was made.

Syringocystadenocarcinoma Papilliferum In Situ, a Variant of Cutaneous Adenocarcinoma In Situ: A Case Report With Literature Review.

Syringocystadenocarcinoma papilliferum in situ, a variant of cutaneous adenocarcinoma in situ, is extremely rare. Only 9 cases have been published to date with 2 cases demonstrating pagetoid epidermal involvement. In this study, we report a case of syringocystadenocarcinoma papilliferum in situ with pagetoid epidermal involvement arising from a long-standing nevus sebaceus on the scalp of a 60-year-old woman.

Basaloid tumors in nevus sebaceus revisited: the follicular stem cell marker PHLDA1 (TDAG51) indicates that most are basal cell carcinomas and not trichoblastomas.

BACKGROUND: Until the 1990s, basal cell carcinoma (BCC) was viewed as the most common epithelial neoplasm developing in association with nevus sebaceus (NS). Currently, trichoblastoma is thought of as the most prevalent basaloid neoplasm in NS. The follicular stem cell marker pleckstrin homology-like domain, family A, member 1 (PHLDA1) also known as T-cell death-associated gene 51 (TDAG51) labels trichoepithelioma (TE) but not BCC. Therefore, we explored its usefulness in basaloid neoplasms developing in NS. METHODS: We studied immunohistochemically PHLDA1 in 10 nodular BCCs, 11 TEs, 11 trichoblastomas and 25 NS with basaloid tumors. Additionally, we examined the expression of BCC marker BerEP4 and the distribution of Merkel cells that function as surrogate markers for benign follicular neoplasms. RESULTS: Nineteen of the 25 basaloid tumors in NS were PHLDA1-negative comparable to BCC arising de novo and six tumors were PHLDA1-positive comparable to solitary trichoblastomas and TEs. Fewer Merkel cells were seen in BCCs associated with NS when compared with trichoblastoma. BerEP4 did not discriminate between the neoplasms. CONCLUSIONS: We raise concern that the unquestioned assessment that basaloid tumors developing in association with NS represent mostly trichoblastomas and not BCC may not be true. This influences clinical care, as it is paramount in the decision of whether to excise these lesions or not.

Immunohistochemical study of cytokeratin expression in nevus sebaceous.

BACKGROUND: The histogenesis of nevus sebaceous (NS) is unclear. METHODS: To elucidate the histogenesis of NS, cytokeratin (CK) profiles were examined immunohistochemically using 10 anti-keratin antibodies in the three stages of NS. RESULTS: In the first stage, stratified differentiated keratins (CK1 and 10) were reduced, and basal keratin (CK14) was increased in the epidermis and primitive follicular structure (PFS). In the second stage, in addition to reduced CK1 and CK10 expressions and increased CK14 expression, CK17 expression was strongly expressed in the sebaceous ducts in proportion to the development of sebaceous gland. In the third stage, CK14, CK17 and CK19 were expressed in secondary tumors. CK16 was not detected throughout all stages of NS. CONCLUSION: These results suggest that NS is not hyperproliferative but involves hamartomatous differentiation with undifferentiated keratins.

Nestin expression in stromal cells of trichoblastoma and basal cell carcinoma.

BACKGROUND: Both trichoblastoma and basal cell carcinoma (BCC) are considered to be a benign and malignant neoplasm of follicular germinative cells respectively. A recent investigation revealed that the mesenchymal cells in the perifollicular sheath and evolving follicular papilla of embryonic hair germs and those cells in hair follicles in early anagen express nestin. OBJECTIVE: The aim of the present study was to investigate whether trichoblastoma and BCC recapitulate the epithelial­mesenchymal interactions in embryonic hair germs or early anagen hair follicles by expressing nestin in stromal cells. METHODS: Immunohistochemical staining was performed with antibody against nestin for 15 trichoblastomas including large/small nodular, retiform and trichoepithelioma types, while adding the superficial type associated with nevus sebaceous and for 20 BCCs including superficial, nodular, nodulo-infiltrative, and infiltrative/micronodular types. RESULTS: In all 15 trichoblastomas, the stromal cells expressed nestin with variable positive reactions, except for superficial trichoblastomas within nevus sebaceous lesions, in which stromal cells were constantly positive for nestin. In all 20 BCCs, the stromal cells were basically negative for nestin. CONCLUSIONS: The development of trichoblastomas incompletely recapitulates the epithelial­mesenchymal interactions in embryonic hair germs or early anagen hair follicles, whereas BCCs fundamentally have lost this ability. Among the various types of trichoblastomas, the superficial type associated with nevus sebaceous was found to have the most similar character to either embryonic hair germs or early anagen hair follicles.

Syringocystadenoma papilliferum with sebaceous differentiation in an intradermal tubular apocrine component. Report of a case.

Syringocystadenoma papilliferum is a benign tumor most commonly located on the scalp or face, and it often arises within a nevus sebaceus of Jadassohn. We describe a 61-year-old man with syringocystadenoma papilliferum developing within a nevus sebaceus with sebaceous differentiation in an intradermal tubular apocrine component of the syringocystadenoma papilliferum. Although some adnexal neoplasms that develop in association with a nevus sebaceus may exhibit conjoint sebaceous, follicular, or apocrine differentiation, reflecting close embryological relations of the folliculosebaceous-apocrine unit, the feature we report on has not previously been described to the best of our knowledge.