Cribriform Tumor of the Skin: Identification of 6q and 9q Loss as a Recurrent Cytogenomic Alteration.

Cribriform tumor is a rare sweat-gland neoplasm of uncertain malignant potential. Although its histopathologic features are well described, the molecular underpinnings of cribriform tumor remain incompletely characterized. We performed comprehensive molecular profiling of 6 cribriform tumors from 3 institutions using whole-exome sequencing, transcriptome sequencing, and single-nucletide polymorphism array copy number analysis. The cohort included 3 women and 3 men (median age, 54 years; range, 40-66 years), with tumors measuring 0.3 to 2.0 cm. Most arose on the extremities, with one located on the back. The most consistent genomic alteration was arm-level losses of chromosomes 6q and 9q, detected in 5 out of 6 cases. These alterations were validated across independent sequencing and single-nucletide polymorphism array platforms. Whole-exome sequencing identified likely pathogenic variants in 2 tumors (CHEK2 p.R145W and NF1 p.R1830H). No gene fusions were detected. Taken together, these findings provide independent confirmation that 6q/9q loss represents a consistent cytogenomic alteration in cribriform tumor, supporting its use as a molecular hallmark of this tumor.