# Metastatic Mammary-Like Adenocarcinoma of the Vulva Responding to Cyclin-Dependent Kinase (CDK) Inhibitor: A Case Report and Literature Review

## TL;DR

A rare case of vulvar cancer resembling breast cancer responded well to a drug targeting cell cycle proteins.

## Contribution

Reports a rare metastatic vulvar tumor responding to CDK inhibitor treatment typically used for breast cancer.

## Key findings

- A 47-year-old patient with metastatic vulvar mammary-like adenocarcinoma showed response to ribociclib and aromatase inhibitor.
- The treatment protocol followed guidelines for HR-positive, HER2-negative breast cancer.
- This case highlights potential therapeutic approaches for this rare tumor type.

## Abstract

Mammary-like adenocarcinoma originating in the vulva is extremely rare, even rarer when metastasized at diagnosis. It may arise from the primitive mammary ridge or mammary-like glands of the skin in the anogenital region. We report a case of a 47-year-old woman with diffuse bone metastasis and a vulvar lesion compatible with mammary-type adenocarcinoma, with no evidence of primary breast cancer. Systemic treatment followed protocols for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer, using an aromatase inhibitor and ribociclib, resulting in a favorable clinical and metabolic response. Documenting this case contributes to the understanding and clinical management of this rare neoplasm.