Multiple follicular hamartomas with sweat gland and sebaceous differentiation, vermiculate atrophoderma, milia, hypotrichosis, and late development of multiple basal cell carcinomas

Bilateral Facial Apocrine Fibrosing Hamartoma Mimicking Microcystic Adnexal Carcinoma

An otherwise healthy 50-year-old woman was evaluated for the presence of 2 erythematous, and slightly pruritic plaques, involving both cheeks for 30 years. Left-side skin biopsy showed a diffuse proliferation of ductal structures horizontally arranged and involving the reticular dermis that resembled tubular adenoma embedded in a sclerotic stroma and surrounded by a peculiar periductal desmoplasia. Nuclear atypia or mitosis was not found. Contralateral biopsy showed identical findings. Differential diagnosis included microcystic adnexal carcinoma (MAC) and plaque-like syringoma and a peculiarly horizontally arranged tubular adenoma. We ruled out MAC as the lesions were long-standing, without infundibular cysts, solid strands, or perineural infiltration. Our case closely resembled those previously described as sweat duct proliferation associated with aggregates of elastic tissue and atrophoderma vermiculatum, although striking differences were observed, as our case did not present aggregates of elastic tissue, did not involve the papillary and superficial reticular dermis, and presented evidences of decapitation secretion as a sign of apocrine differentiation. We consider our case as a MAC simulator and we propose the descriptive name of bilateral facial apocrine fibrosing hamartoma.

Bcl-2, CD34 and CD10 expression in basaloid follicular hamartoma, vellus hair hamartoma and neurofollicular hamartoma demonstrate full follicular differentiation

Generalized basaloid follicular hamartoma syndrome (GBFHS) is a rare, recently-described, autosomal-dominantly inherited disorder that presents with disseminated milia, palmoplantar pitting, hypotrichosis and basaloid follicular hamartomas (BFH). BFH is a benign adnexal tumor that resembles basal cell carcinoma (BCC). In this study, we report two cases of GBFHS and stain BFH, a vellus hair hamartoma (VHH) and a neurofollicular hamartoma (NH) with CD34, bcl-2 and CD10 to characterize and compare the staining patterns of these follicular tumors. Standard immunohistochemistry labeling with CD34, bcl-2 and CD10 was performed on paraffin-embedded, formalin-fixed tissue sections of five BFH (four for CD10), one VHH and one NH. CD34 stromal staining was observed in all specimens. Bcl-2 stained the outermost cell layers of the basaloid nests in all specimens. CD10 stained the peritumoral stroma of all specimens. The BFH, NFH and the VHH showed CD10 staining of matrical cells. CD34 and CD10 stain peritumoral stroma of BFH, VHH and NH. Bcl-2 stains the outermost cell layer of these tumors. CD10 was also observed to stain matrical cells. These results show the similarities in differentiation between these benign follicular neoplasms and trichoepithelioma.

Bazex-Dupré-Christol syndrome in a 1-year-old boy and his mother

Bazex-Dupré-Christol syndrome is a rare genodermatosis with cancer predisposition, characterized by follicular atrophoderma, multiple milia, congenital hypotrichosis, hypohidrosis and basal cell malformations that include nevoid basal cell carcinomas of early onset. We present two patients with this syndrome, a 1-year-old boy with diffuse scalp and eyebrows alopecia, milia papules on the face, ears, trunk, and limbs. Hypohidrosis was observed on his trunk and head. His 16-year-old mother had identical changes since childhood, with hair fragility, and multiple atrophic "ice pick" follicular depressions on the dorsa of her hands. She also had a basal cell carcinoma on her face. Microscopic examination of hairs from the mother revealed abnormalities such as diameter irregularities, broken shafts, trichorrexis nodosa and pili bifurcatti. Pili bifurcatti is an uncommon hair shaft dysplasia that has not before been observed in Bazex-Dupré-Christol syndrome.

Autosomal dominantly inherited generalized basaloid follicular hamartoma syndrome: report of a new disease in a North Carolina family

BACKGROUND

An 8-year-old girl presented with hundreds of milia, measuring 1 to 2 mm; comedone-like lesions; skin-colored and hyperpigmented papules on the face, scalp, ears, neck, upper trunk, and lower arms along with diffuse scalp hypotrichosis; and pinpoint palm/sole pits. Onset was in early childhood and the disease was historically present in 6 generations.

OBJECTIVE

Our objectives were to delineate the clinical and histopathologic features and mode of inheritance as a base for gene studies.

METHODS

Eighteen family subjects were studied. Twenty-six skin biopsy specimens were examined. A detailed pedigree was constructed. A complete literature search was done concerning diseases with generalized basaloid follicular hamartomas.

RESULTS

The lesions were basaloid follicular hamartomas and other folliculocentric abnormalities. Inheritance was autosomal dominant. Extensive literature search confirmed the finding of a unique genodermatosis.

CONCLUSION

A new genodermatosis termed dominantly inherited generalized basaloid follicular hamartoma syndrome was defined by delineating its clinical and histopathologic features and mode of inheritance and by extensive literature review.

Trichoepithelioma papulosum multiplex

Trichoepithelioma papulosum multiplex is an uncommon autosomal dominant disorder in which multiple trichoepitheliomas are seen. Its cause may be a defective tumor suppressor gene. Studies have mapped this gene to the 9p21 locus. However, there is a parallel or identical syndrome of multiple trichoepitheliomas and cylindromas. Within a given family, some members may have cyclindromas whereas others may have trichoepitheliomas or a combination of both. Although preliminary evidence suggests a different gene is responsible, it is possible that TPM may be caused by more than two independent genes, with some cases of TPM due to impairment of the gene for cylindromatosis. This entity, as well as other disorders with multiple appendageal tumors, may require clarification and distinction from TPM.