Abnormal Cystic Tumor in a Patient with Hereditary Leiomyomatosis and Renal Cell Cancer Syndrome: Evidence of a Precursor Lesion?

الملخص EN

The hereditary leiomyomatosis and renal cell cancer (HLRCC) association is a rare syndrome caused by mutation of the Kreb’s cycle enzyme, fumarate hydratase (FH).

It is characterized by unusually aggressive type 2 papillary renal cell histology.

FH is responsible for catalyzing the conversion of fumarate to malate.

Its absence leads to a state of “pseudohypoxia,” inducing hypoxia inducible factor 1α (HIF-1α) and leading to increased growth factor transcription (e.g., vascular endothelial growth factor, VEGF; glucose transporter 1, GLUT1).

Ultimately, this results in tumorigenesis.

We present a patient who was diagnosed with HLRCC and underwent bilateral nephrectomies.

One of the nephrectomy specimens was notable for benign cystic lesions that stained positive immunohistochemically for succinated proteins, a finding only noted in FH-deficient cells.

Thus, we posit a potential precursor lesion to type 2 papillary renal cell carcinoma in the HLRCC syndrome.