We report here a case of bilateral renal cell carcinoma in a patient undergoing long-term dialysis, which showed false-positive immunoreactivity for TFE3 immunostaining.
Regarding translocation renal cell carcinoma (RCC), TFE3, TFEB and ALK protein expression is crucial in establishing the diagnosis of Xp11.2 RCC, renal carcinoma with t(6;11)(p21;q12), and renal carcinoma with ALK rearrangement, respectively.
Xp11 translocation renal cell carcinomas are a group of neoplasms distinguished by chromosomal translocations with breakpoints involving the TFE3 transcription factor gene, which maps to the Xp11.2 locus.
Molecular cytogenetic analysis for TFE3 rearrangement in Xp11.2 renal cell carcinoma and alveolar soft part sarcoma: validation and clinical experience with 75 cases.
Recently, a small subgroup of PEComas has been recognized to harbor rearrangements involving TFE3, a gene also involved in rearrangements in translocation-associated renal cell carcinomas and alveolar soft part sarcomas.
Ten tumors were originally diagnosed as Xp11.2 RCC on the basis of positive TFE3 immunostaining, and 14 were originally considered unclassified RCCs with negative or equivocal TFE3 staining, but with a range of features suspicious for Xp11.2 RCC.
Several novel subtypes have been introduced, i.e. mucinous tubular and spindle cell carcinoma, and Xp11.2/TFE3 translocation-associated renal cell carcinoma.
Here, we describe a case of TFE3-positive RCC in which metastatic relapse to the mediastinal lymph nodes and pulmonary nodules was treated with single-agent sunitinib, a multitargeted tyrosine inhibitor.
Our results suggest that weak TFE3 staining of a significant proportion of RCC cases may be because of expression of the full-length TFE3 protein rather than the chimeric fusion protein resulting from chromosomal translocation.
To identify the best marker for alveolar soft part sarcoma in formalin-fixed, paraffin-embedded tissues, we evaluated the sensitivity and specificity of the detection of the ASPSCR1-TFE3 fusion transcript along with the immunoreactivity for TFE3 and CD147 in 24 alveolar soft part sarcomas and 23 non-alveolar soft part sarcoma tumors, including 5 granular cell tumors, 5 paragangliomas, 3 clear cell sarcomas, and 10 clear cell renal cell carcinomas.
We immunohistochemically analyzed TFE3 nuclear expression in 809 cases of RCCs using 14 tissue microarray blocks and selected nine cases those showed moderate to strong positive nuclear immunoreactivity for TFE3.
The latter can be useful diagnostically, especially when alveolar soft part sarcoma presents in an unusual site (such as bone) or with clear cell morphology, which raises the differential diagnosis of metastatic ASPSCR1-TFE3renal cell carcinoma.
Since TFE3 is implicated in RCC, we hypothesized that elevated GPNMB expression was due to increased TFE3 activity resulting from the inactivation of FLCN.