Xp11.2 translocation renal cell carcinoma occurring during pregnancy with a novel translocation involving chromosome 19: a case report with review of the literature

Immunohistochemically, the tumor showed strong nuclear positivity for TFE3. Epithelial membrane antigen, CD10, and E-cadherin were strongly positive. Cytokeratin AE1/AE3, cytokeratin CAM-5.2, calveolin, and parvalbumin were moderately positive. Cytokeratin 7, renal cell carcinoma antigen, and colloidal iron were focally weakly positive. BerEP4 and carbonic anhydrase IX were negative. Cytogenetically, the tumor harbored a novel variant translocation involving chromosomes X and 19, t(X;19)(p11.2;q13.1). Interphase FISH analysis performed on cultured and uncultured tumor cells using a dual-color break-apart DNA probe within the BCL3 gene on 19q13.3 was negative for the BCL3 gene rearrangement. She received no adjuvant therapy, delivered a normal term baby five months later, and is alive without evidence of disease 27 months after diagnosis and surgery. Unlike most recently reported Xp11.2 translocation RCCs in adult patients with aggressive clinical course, this adult case occurring during pregnancy with a novel translocation involving chromosome 19 followed an indolent clinical course.Xp11.2/TFE3 translocation renal cell carcinomas (RCCs), a recently classified distinct subtype, are rare tumors that usually affect children and adolescents [1-8], with only few reported adult cases to date [9-24]. It is estimated that approximately one-third of pediatric RCCs are Xp11.2 translocation RCCs [2-5], whereas conventional clear cell RCCs make up about 15% of pediatric RCCs [25,26]. In contrast, conventional clear cell RCCs make up 70% of RCCs in adults and 53% in young adults [26], but the incidence of Xp11.2 translocation RCCs in adults and young adults is much smaller (estimated to be perhaps 1%) [1,5,7,17,19,27]. Xp11.2 translocation RCCs are defined by at least six different translocations involving the Xp11.2 chromosome, all of which result from gene fusions involving the TFE3 transcription factor gene, and their morphology and biological behavior are not widely recogniz