G-CSF producing pleomorphic carcinoma with undetected origin: an autopsy case report

Pleomorphic carcinoma is an uncommon neoplasm that is known to arise in diverse sites, including the lung, breast, pancreas, gallbladder and prostate. We encountered a rare case of pleomorphic carcinoma of undetected origin associated with production of granulocyte-colony stimulating factor (G-CSF). The patient was a 62-year-old man who presented with cough and general fatigue. Chest computed tomography (CT) demonstrated a mass lesion in the mediastinum, so mediastinoscopic tumor biopsy was performed. However, making the diagnosis was difficult despite the suspected malignant potential. CT-supported positron emission tomography showed multiple uptake lesions in the small intestine, duodenum and right adrenal gland, in addition to the mediastinum. The patient subsequently presented with right-side weakness and sensory impairment. Brain CT showed multiple intracerebral lesions, indicating metastatic tumors. For the definitive diagnosis and to clarify options for chemotherapeutic management, the patient underwent surgical craniotomy. The resected specimen was considered to represent sarcomatoid carcinoma with positive immunoreactive staining for cytokeratin as an epithelial marker, indicating pleomorphic carcinoma. Furthermore, laboratory data showed leukocytosis without any infections and elevated serum G-CSF levels during hospitalization. The patient developed complications of occlusive intussusception in the small intestine caused by probably metastatic lesions and died from disease progression 82 days after initial admission. Although the presence of G-CSF-producing pleomorphic carcinoma was confirmed, the primary origin of this pleomorphic carcinoma could not be indentified clearly even at autopsy.