Merkel cell carcinoma (MCC) is a rare malignant neoplasm, mostly affecting the skin (97% of cases). It is usually found in elderly people, in the sun-exposed areas of the skin. About 50-60% of MCC cases are located on the head and the neck, less often on the extremities and the torso, and extremely rarely in the genital area. Ultraviolet radiation may be the main factor responsible for the development of the tumors but viral etiology is also debated. Due to extremely rare incidence of MCC in the area of the vulva, proper management remains a challenging task.
Aim: To present a case of an aggressive MCC of the vulva and a review of the literature.
Material and methods: A previously healthy 72-year-old patient presented at the Oncology Center of the Maria Sklodowska-Curie Institute, Warsaw, in June 2010. Four months previously the patient noticed a painless lump in the vestibular region of the vagina. She received anti-inflammatory treatment at her local gynecological clinic, with no success. In February the patient underwent removal of the vulvar tumor Histopathological examination confirmed anaplastic carcinoma. Microscopic evaluation revealed the tumor diameter to be 15mm. Surgical margins were free of neoplastic infiltration. The patient did not receive adjuvant therapy due to the results from the histopathological protocol. The disease recurred after three months. Radical vulvectomy and bilateral inguinal femoral lymphadenectomy were performed in May 2010. Histopathological examination confirmed microcellular carcinoma with no metastases to the lymph nodes and complete resection of the tumor (RO). The disease recurred in the next two months: a 50-mm tumor was found in the right inguinal lymph nodes. The decision to verify all histopathological material obtained during all procedures performed so far was made. Immunohistochemical evaluation confirmed MCC. Adjuvant radiotherapy was recommended. The area of the vulva, pelvic and inguinal lymph nodes were irradiated. One month after therapy completion the patient complained of pain in the lumbar area. An ultrasound examination of the abdomen revealed a tumor (9 cm in diameter) in the para-aortic region but it was not histopathologically verified due to extremely poor overall condition of the patient. As the condition of the woman deteriorated systematically the patient was referred to a hospice facility where she died 9 months since the primary diagnosis.
Conclusions: MCC of the vulva is a rare neoplasm with an aggressive course. Clinical and histopathological diagnostic difficulties and consequently lack of standardized management, result in low survival rates.