Metastatic renal clear cell carcinoma mimicking stage IV lung cancer

We present a 63-year-old man who wasinvestigated for a lesion in the apex of theleft lung and a coexisting osteolytic lesion inthe right major trochanter. FNA of the thoracicmass was suggestive for malignancy yet notdiagnostic regarding the tumor type and thesite of the primary tumor. A diagnosis of astage IV lung cancer was favored and heunderwent a left exploratory thoracotomy inview to resect the primary tumor. Anextrapulmonary mass localized to the pleura notinvolving the ipsilateral lung was disclosed.Multiple biopsies revealed metastatic clearcell RCC. A 5×7 cm left renal tumor wasrevealed in a postoperative abdominal CT scan.He was treated with combination of interferon Aand vinblastin followed by radical nephrectomy.Twenty-four months after the diagnosis he is alivewithout evidence of local or distant recurrence.Pleural metastases from RCC are mainlypresented as malignant pleural effusions.Thoracic metastatic lesions localized to thepleura, forming solitary or multiple mass(es)have been rarely reported. We review theliterature regarding this rare clinicalmanifestation of the disease and we discussdiagnostic and therapeutic options.