Concomitant sentinel lymph node biopsy leading to abbreviated systematic lymphadenectomy in a patient with primary malignant melanoma of the vagina

INTRODUCTION: Primary malignant melanoma of the vagina is an extremely rare disease affecting 3% of patients with malignant vaginal tumors. It is rare compared to primary malignant melanoma of the skin and its prognosis is unfavorable even in patients with Stage I disease. Here, we report a case of primary malignant melanoma of the vagina and discuss our experience with regard to previously published literature. CASE DESCRIPTION: The patient was a 59-year-old female with 2 prior pregnancies and child births. She was examined by a local doctor for swelling of the genitalia, and a 1.8 × 1.0 cm large tumor was detected on the left side of the vaginal wall. A biopsy indicated leiomyosarcoma, and she was referred to our hospital. The tumor was resected, and histopathology of the resected sample confirmed the diagnosis of malignant melanoma based on a positive surgical margin. Additional courses of treatment included left inguinal sentinel lymph node biopsy using an isotope and extended vaginectomy. Although the sentinel node was negative, we performed a modified radical hysterectomy and left vaginectomy during the third operation because the surgical margin was positive. We could not confirm whether the lesion in the extracted sample was malignant, and the final diagnosis was primary malignant melanoma of the vagina T4bN0M0 Stage IIc (UICC 2009). Postoperative adjuvant therapy consisted of 6 cycles of DAV-Feron therapy (dacarbazine, ACNU, vincristine, IFN- β). After 5 months of postoperative adjuvant therapy, a 2 cm single lung metastasis was detected in the lower left lung. We performed a laparoscopic lower left lobectomy and are planning additional chemotherapy. DISCUSSION AND EVALUATION: Currently, surgical resection has the highest probability of improving the prognosis of patients when used as initial treatment for Stage I disease. By combining treatment with sentinel lymph node biopsy, we were able to accurately determine the stage of disease and thus avoid systematic lymph node dissection and further surgical treatments. CONCLUSION: Malignant melanoma of the vagina is very rare tumor so it is necessary to requires the integration of further cases.