Genetic testing of leiomyoma tissue in women younger than 30 years old might provide an effective screening approach for the hereditary leiomyomatosis and renal cell cancer syndrome (HLRCC)

Abstract

We have studied the viability of targeted molecular screening for the identification of female patients with hereditary leiomyomatosis and renal cell cancer (HLRCC) syndrome. Affected patients harbor a germ-line heterozygous mutation of the fumarate hydratase (FH) gene. Clinically, some patients present with aggressive renal cell carcinoma. Concerning women, in almost all cases, this is preceded by symptomatic uterine leiomyoma. We aimed to identify women operated on for symptomatic leiomyoma by the age of 30. Archived paraffin-embedded leiomyoma tissue was tested for the FH gene mutation in 14 cases. Two patients with multiple leiomyomas and with the confirmed germ-line mutations c.1433_1434dupAAA, p.(Lys477dup) and c.953A>T, p.(His318Leu) were identified and enrolled in a surveillance program. Statistically significant correlation between the presence of multiple uterine leiomyomas (more than seven in our experience) and the FH gene mutation was found. The immunohistochemical expression pattern, of simultaneous FH absence and S-(2-succino)cysteine (2SC) positivity, correlated with the results of the molecular genetic study in only one case. The histomorphologically simultaneous detection of enlarged nucleoli with a clear halo of leiomyocyte nuclei, their fibrillary cytoplasm, the presence of eosinophilic globules, and staghorn vessels proved to be only a partially sensitive indicator of HLRCC-associated leiomyoma and fully correlated with immunohistochemistry and molecular genetic study only in one case. Molecular genetic testing is presently the only reliable diagnostic tool able to identify HLRCC patients. The sensitivity and specificity of the presence of multiple leiomyomas in women with the FH gene mutation who are younger than 30 years old should be confirmed in larger scale studies. The applied targeted molecular screening protocol proved to be effective, resulting in identification of two positive patients out of fourteen tested individuals.

Tubulocystic Carcinoma of the Kidney With Poorly Differentiated Foci

“…Again, for the first cohort of new cases, immunohistochemistry for FH was performed by use of clone J-13, Santa Cruz Biotechnology, essentially as reported previously (19, 20), but at dilution of 1:1000 or at 1:100 under CLIA-validated IHC testing protocols performed by two of our IHC labs (a subset of our cases were studied by both with identical results). Our 2SC staining protocol has been reported previously (14).…”

“…The 2SC staining assessed for intensity (1+ to 3+) and staining pattern (nuclear and cytoplasmic vs. cytoplasmic only), though only 3+ intensity nucleocytoplasmic staining was interpreted as positive, also as reported previously (14). Reflective of experience of ours (14, 20, 23) and others (15-17, 19) with relation of FH and 2SC immunophenotype to FH mutational status, we classified the immunophenotypes observed as FH+2SC- as “FH-retained”, FH-2SC+ as “FH-deficient”, and FH±2SC+ as “FH-suspicious”.…”

“…Importantly, HLRCC-RCCs are exceptionally aggressive tumors, often presenting at high stage, underscoring the importance of their recognition (12, 14). Thus recent reports propose immunohistochemical adjuncts for screening for HLRCC-RCCs, including staining for FH protein expression, which may be lost in a majority of cases (15-18) and for aberrant succination of nuclear and cytoplasmic proteins (S-(2-succino)-cysteine, 2SC), which is induced upon loss of FH function (14, 17, 19, 20). …”

Loss of Fumarate Hydratase and Aberrant Protein Succination Detected With S-(2-Succino)-Cysteine Staining to Identify Patients With Multiple Cutaneous and Uterine Leiomyomatosis and Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome

“…9 This hypothesis, namely, the production of a stable but inactive enzyme might explain the moderately positive, grade 2 immunostaining found in 2 of our genetically confirmed cases of HLRCC syndrome and it could also explain the peculiar staining pattern found in the only patient with sporadic multiple piloleiomyomas. This hypothesis would also explain the presence of FH expression without 2SC increase in 1 of the 2 confirmed uterine leiomyomas associated with HLRCC syndrome in the article of Martinek et al 13 Moreover sporadic leiomyomas may also portend somatic FH mutations as previously described in uterine ones. 14 …”

“…If we found a strongly positive staining we can almost completely rule out MCUL/HLRCC syndrome, but we should remember that in uterine leiomyomas, positive fumarase staining may be found in patients with HLRCC syndrome, although intensity is not regarded. 13 In the other cases in which weak positive FH or negative FH staining is seen, we should add anti-2SC staining, and if negative staining is found, then, the possibility of that syndrome is unlikely (Fig. 1).…”