Fibroadenoma in vulval ectopic breast tissue in a patient with PTEN Hamartoma Tumour Syndrome

Abstract

PTEN is a tumour suppressor gene involved in regulating cell division. Pathogenic germline variants in PTEN predispose to benign and malignant growths of numerous organs, including of the breast. In the following report, we describe the first documented case of a fibroadenoma developing in ectopic breast tissue of the vulva in a patient with a germline pathogenic variant in PTEN. This highlights the risk of proliferative hyperplasia developing in any breast tissue, including rare ectopic sites, particularly in patients with underlying germline variants in cancer susceptibility genes.

Fibroadenoma of the vulva with pseudoangiomatous stromal hyperplasia: A common neoplasm in uncommon site

“…It may be advisable to screen patients with a renal ultrasound following a diagnosis of ectopic breast lesion. One vulvar fibroadenoma was diagnosed in a patient with PTEN hamartoma tumor syndrome, an autosomal dominant condition with increased risk of benign breast disease, hamartomatous overgrowth of tissues, and malignancies 20 . By immunohistochemistry, the vulvar lesional cells showed patchy PTEN loss.…”

“…One vulvar fibroadenoma was diagnosed in a patient with PTEN hamartoma tumor syndrome, an autosomal dominant condition with increased risk of benign breast disease, hamartomatous overgrowth of tissues, and malignancies. 20 By immunohistochemistry, the vulvar lesional cells showed patchy PTEN loss. In summary, mammary-type tissue and associated lesions should be considered when investigating a vulvar lesion.…”