Background: Malignant lesions on the vulva are very rare in young women. Inspite of all the development in modern medicine their origin sometimes remains undiscovered and their development cannot be explained. Patients and methods: We describe a case of a 22-year-old woman, who was initially treated for what was believed to be an atheroma of the vulva. A biopsy was performed. The histology revealed a malignant metastatic lesion. Extensive diagnostic procedures were performed (gynecologic ultrasound, ultrasound of the abdomen, CT, MR, PET CT) and foreign specialists in gynecologic pathol- ogy were consulted. Conclusions: Although extensive diagnostic procedures were performed the origin of the malignant change causing the described lesion remained a mistery.