RESUMEN
In this article, we searched for the common histologic characteristic of renal tumors in patients with Birt-Hogg-Dubé syndrome (BHDS). We selected 6 patients with histologically confirmed renal tumor in BHDS. Germline FLCN gene mutation has been identified in 5 patients. Multifocality and bilaterality of the renal tumors were pathologically or radiologically confirmed in 5 and 2 cases, respectively. Histologic subtypes of the dominant tumor included 3 previously described hybrid oncocytic tumors, one composite chromophobe/papillary/clear cell renal cell carcinoma (RCC) and one unclassified RCC resembling hybrid chromophobe/clear cell RCC. In one case, chromophobe RCC and clear cell RCC were separately observed. Small papillary lesions located in the peripheral area of the tumor, which we designated as intratumoral peripheral small papillary tufts, were identified in all patients. In conclusion, multifocality/bilaterality of renal tumors, discordance of histologic subtypes, and the presence of intratumoral peripheral small papillary tufts may be important clues to identify BHDS-associated renal tumors.
Asunto(s)
Síndrome de Birt-Hogg-Dubé/patología , Carcinoma Papilar/patología , Carcinoma de Células Renales/patología , Neoplasias Renales/patología , Anciano , Biopsia , Síndrome de Birt-Hogg-Dubé/genética , Carcinoma Papilar/genética , Carcinoma de Células Renales/genética , Femenino , Humanos , Neoplasias Renales/genética , Masculino , Persona de Mediana Edad , Neumotórax/genética , Neumotórax/patología , Proteínas Proto-Oncogénicas/genética , Proteínas Supresoras de Tumor/genéticaRESUMEN
Birt-Hogg-Dubé syndrome is a familial genodermatosis, of which patients frequently develop renal neoplasms, fibrofolliculomas and pneumatocele. Here, we report a mother and daughter with renal neoplasms surgically resected (69 and 46 years-of-age at surgery, respectively). The mother's tumor was diagnosed as an unclassified type renal cell carcinoma associated with microscopic tumorous nodules, whereas the daughter's tumor was a hybrid oncocytic/chromophobe tumor. The germline mutation analysis of the responsible gene, FCLN (the folliculin gene), showed a deletion of 18 bp in exon 5 (c.332_349del/p.H111_Q116del), predicting an alteration of the amino acid sequence of "HPSHPQ" replaced by a single amino acid, "L". This is a novel germline mutation of the FCLN gene that has not been previously reported.