Vulvar Pilomatrix Carcinoma: Morphologic and Molecular Features.

Abstract

Pilomatrix carcinoma (PC) is a rare malignant variant of pilomatrixoma, a skin adnexal tumor originating from hair matrix cells. It is most often located in the head, neck region, upper back and upper extremities. PC has a locally aggressive behavior but metastasis only occur in 10% of cases. Mutations in CTNNB1, the encoding gene of beta-catenin, have been found in both pilomatrixoma and PC, but other molecular alterations are unknown. The authors present a case of PC in the clitoris, the third known reported case located on the external genitalia. The tumor followed an unusual clinical course with the development of multiple metastases. Next-generation sequencing analysis of the tumor identified, in addition to a characteristic CTNNB1 mutation, pathogenic mutations in PTEN, PIK3CA, and ARID1A, which could explain the aggressive course of the disease. The diagnostic criteria of PC and the differential diagnoses of this unusual tumor in the genital area are discussed.

• Authors: Diego Bueno, Tamara Caniego-Casas, María Concepción Sánchez-Martínez, Cristina Saavedra-Serrano, José Palacios, Belén Pérez-Mies
• Journal: International journal of gynecological pathology : official journal of the International Society of Gynecological Pathologists (Int J Gynecol Pathol) Vol. 40 Issue 5 Pg. 482-486 (Sep 01 2021) ISSN: 1538-7151 [Electronic] United States
• PMID: 33252403 (Publication Type: Case Reports, Journal Article)
• Copyright: Copyright © 2020 by the International Society of Gynecological Pathologists.

Chemical References

• CTNNB1 protein, human
• beta Catenin

Topics

• Diagnosis, Differential
• Female
• Hair Diseases (diagnosis, genetics, pathology)
• High-Throughput Nucleotide Sequencing
• Humans
• Middle Aged
• Mutation
• Pilomatrixoma (diagnosis, genetics, pathology)
• Sequence Analysis, DNA
• Skin Neoplasms (diagnosis, genetics, pathology)
• Vulva (pathology)
• Vulvar Neoplasms (diagnosis, genetics, pathology)
• beta Catenin (genetics)