BROOKE-SPIEGLER-SYNDROME VARIANT - SEGREGATION OF TUMOR TYPES WITH MIXED DIFFERENTIATION IN 2 GENERATIONS

Brooke-Spiegler syndrome (BSS) is an autosomal dominantly inherited di sease characterized by the development of multiple trichoepitheliomas and cylindromas. Other lesions have been reported to occur in patients with BSS, including parotid basal cell adenomas, milia, organoid nevi , basal cell carcinomas, and spiradenomas. Spiradenomas and cylindroma s have so many features in common that they have been regarded as pola r extremes belonging to a spectrum of cutaneous adnexal neoplasms. We report on a 61-year-old woman with multiple spiradenomas on the scalp and periauricular areas and her 28-year-old daughter, with multiple fa cial trichoepitheliomas. Occasional features of pilar and ductal diffe rentiation were found in tissue specimens of tumors from the mother an d daughter, respectively. Co-existence of multiple spiradenomas and tr ichoepitheliomas and segregation of the predominant type of tumor in d ifferent members of a family with BSS have been reported occasionally, but never, to our knowledge, in combination. The presence of mixed di fferentiation in tumor specimens from both patients provides additiona l evidence in support of the folliculosebaceous apocrine unit (FSAU) h ypothesis. Mutations in genes regulating proliferation and differentia tion of putative stem cells of the FSAU would give rise to different c ombinations of adnexal skin tumors as well as to other neoplasms.