Siladepa al día Nº 1

CONCLUSION DEL CASO

Tricoepitelioma multiple.

Historia.-

Es un tumor descrito por primera vez en 1885 por Balzer y Menetrier,  nombrandolo como adenomas sebaceos de la cara y cuero cabelludo. 1892 el Dr. Brooke lo llamo epiteloma adenoide quistico y casi simultaneamente Fordyce le da el nombre de epitelioma  quistico benigno multiple de la piel.  En 1894, Jarish fue el primer autor en reconocer que existian dos cuadros clinicos diferentes que  correspondian,  respectivamente al tricoepitelioma simple y al tricoepiteloma desmoplasico, ademas de ser el primero que propuso el termino de tricoepitelioma para esta neoplasia.  Savatard en 1922 reviso varios casos de tricoepiteliomas multiples y observo que la mayoria de los casos eran familiars aunque existian formas no hereditarias de la enfermedad.

Clinica.-

Los tricoepiteliomas multiples constituyen generalmente una genodermatosis de herencia autosomica dominante con menor expresividad y penetrancia en los varones, aunque tambien se han descrito casos esporadicos. Aparentemente la alteracion genetica es a nivel del cromosoma 9p21. Las lesiones se presentan en forma de pequenas papulas de apariencia translucida, que a veces pueden agruparse formando placas  y  se localizan preferentemente en la region  central de la cara con mayor profusion en  los surcos nasogenianos.  Generalmente, lo primeros tricoepiteliomas  comienza aparecer en la infancia o en la pubertad y su numero se incrementa en hasta la vida adulta.

Histologia.-

El tricoepitelioma es una variante superficial del tricoblastomay, po lo tanto muestra caracteristica de neoplasia benigna, apareciendo como una lesion  simertica y bien circunscrita, compuesta fundamentalmente por celulas germinativas foliculares y con abundante estroma fibrocitario.  La lesion se localiza predominantemente en dermis y puede presenta diferentes patrones histopatologicos. El componente epitelial esta representado por islotes de celulas germintivas foliculares que con frecuencia adoptan una disposicion adenoide, cribiforme o esterofirme y muestran una hilera follicular periferica dispuesta en palizadas. El principal diagnostico diferencial es el carcinoma basocelular  infundibulo-quistico.

Referencia.-

Am J Dermatopathol. 2011 May;33(3):251-65. doi: 10.1097/DAD.0b013e3181f7d373.

Multiple (familial) trichoepitheliomas: a clinicopathological and molecular biological study, including CYLD and PTCH gene analysis, of a series of 16 patients.

Kazakov DV1, Vanecek T, Zelger B, Carlson JA, Spagnolo DV, Schaller J, Nemcova J, Kacerovska D, Vazmitel M, Sangüeza M, Emberger M, Belousova I, Fernandez-Figueras MT, Kempf W, Meyer DR, Rütten A, Baltaci M, Michal M.

Author information

Erratum in

Am J Dermatopathol. 2011 Dec;33(8):874. Fernandez-Figueraz, Maria Tereza [corrected to Fernandez-Figueras, Maria Tereza].

Abstract

Multiple familial trichoepitheliomas (MFT) constitute an autosomally inherited syndrome possibly related to Brooke-Spiegler syndrome (BSS). Although some early studies suggested a role for the PTCH gene on chromosome 9q22.3 in the etiopathogenesis of MFT, recent studies of occasional patients with the MFT clinical phenotype identified mutations in the CYLD gene on chromosome 16q12-q13, a gene responsible for BSS. A systematic investigation of PTCH and CYLD mutations in patients with MFT has never been performed. Our main objective was to collect a reasonably large series of patients with MFT to (1) study the clinicopathological spectrum of the disease, (2) determine whether the PTCH gene is implicated in the pathogenesis of MFT, and if so (3) determine the relative frequency of CYLD and PTCH mutations, (4) establish if there may be any possible genotype-phenotype correlations, and (5) study the spectrum of somatic mutations. Clinical analysis including family histories, histopathological investigations, and molecular genetic studies were performed. There were 9 female and 7 male patients ranging in age from 11 to 63 years. They presented with multiple, small, discrete and sometimes confluent, skin-colored to pink, asymptomatic nodules preferentially located on the face, being especially prominent and confluent in the nasolabial folds and inner aspects of the eyebrows. A total of 66 conventional trichoepitheliomas (TEs) were studied microscopically. Aside from typical features of TE, some also exhibited variant morphological patterns including areas reminiscent of other benign adnexal neoplasms and melanocytic hyperplasia. In none of the 9 patients tested was a germline mutation of the PTCH gene identified. Germline CYLD mutations were detected in 6 of 13 patients tested (identical in 2 unrelated patients) including 2 novel mutations, whereas the remaining 7 individuals showed wild-type alleles. Two patients with germline wild-type CYLD showed, however, a somatic mutation in the gene (1 duplication, 1 substitution mutation). Neither CYLD nor PTCH germline mutations were found in the 5 patients in whom both genes were analyzed. MFT seems to be a phenotypic variant of BSS. The PTCH gene is rarely, if ever, involved in the pathogenesis of MFT. Absence of a germline mutation of the CYLD gene in cases harboring a somatic mutation may be explained by large deletions in the gene or by mutation in intronic sequences or in the promoter region. Considering our 5 patients with no mutation in either gene, the final possibility is that another, as yet undescribed gene (neither CYLD nor PTCH) is implicated in the pathogenesis of some patients with MFT.