The Undifferentiated Carcinoma That Became a Melanoma: Re-biopsy of a Cancer of an Unknown Primary Site

A Case Report

Oluf Dimitri Røe; Sissel Gyrid Freim Wahl


J Med Case Reports. 2017;11(82) 

In This Article


Cancer of unknown primary site (CUP) accounts for approximately 1 to 5 % of all cancers but has a dismal prognosis of approximately 10 to 20 % 1-year survival and in Australia is the sixth cause of cancer death.[1–4] Depending on the patient series, up to 40 % of patients with CUP are diagnosed as having metastasis in their lymph nodes, while the remaining patients present with metastasis in their internal organs.[5,6] In a large series of CUP in various anatomical regions, patients with an affected lymph node showed a wide survival span; patients presenting with affected inguinal lymph nodes had a median survival of 18 months and patients affected intra-abdominally had a median survival of only 4 months.[7] Thus CUP is a very heterogenous entity, where histopathological examination, immunohistochemical profiling, and molecular profiling of the tumor are necessary to improve treatment and survival of patients with these tumors.

The complexity and unusual features of the history of this 62-year-old woman with a fast-growing mass in her left inguinal area, has taught us a lesson that may be important to share with oncologists treating this patient population.