A Metastatic Granulocyte Colony-Stimulating Factor Producing Sarcomatoid Carcinoma of the Lung Causing Jejunal Intussusception - Report of a Case -

Abstract

Granulocyte colony-stimulating factor (G-CSF) producing lung cancer, first described by Asano et al. 1 in 1977, is a well known highly malignant cancer with poor prognosis. Among the G-CSF producing lung cancer types, two thirds are large cell carcinomas followed by squamous cell carcinoma. 2,3 Sarcomatoid carcinoma of the lung is a rare histological type of lung cancer with a mixture of biphasic epithelial and stromal tumor cells. 4 It may be difficult to histologically identify the two components. Currently, it is necessary to confirm the components using immunohistochemistry, electron microscopy, and molecular assays. Metastatic sites associated with sarcomatoid carcinoma are similar to the more common non-small cell lung carcinoma, with unusual metastatic sites such as the esophagus, jejunum, and kidneys having been reported. 5 To the best of our knowledge, there are no prior reports of a patient with multiple small bowel metastases from a sarcomatoid carcinoma producing G-CSF and resulting in an intestinal intussusception. CASE REPORTA 75-year-old male heavy smoker was admitted to the hospital with epigastric pain, nausea, and vomiting. The physical examination revealed epigastric tenderness and hyperactive bowel sounds. Body temperature was 37.3˚C, white blood cell (WBC) counts were 63,630/mm³ (neutrophil 95%), and chest X-ray revealed a mass in the right lower lung field. The C-reactive protein was measured at 30.07 mg/mL and there was no evidence of infection on routine examination. Follow-up diagnostic tests with chest and abdominal dynamic computed tomography (CT) imaging revealed a homogeneous mass measuring 9 cm in diameter in the right lower lobe of the lung (Fig. 1), in addition to a jejuno-jejunal intussusception (Fig. 2). An emergency small bowel resection was performed for the reduction of the intussusception. Pathology displayed seven ulcero-fungating masses in the duodenum and jejunum. The size of the masses ranged from 7.0×4.0×1.0 cm to 4.0×3.8×0.8 cm. The cut surface of the tumors was whitish and firm. The microscopic A 75-year-old man was referred to our hospital with intestinal obstruction caused by intussusception. Abdominal computed tomography (CT) revealed seven polypoid masses in the small intestine, while chest CT revealed a mass in the right lower lobe. Preoperative laboratory tests showed white blood cell (WBC) and neutrophil differential counts of 63,630/mm³ and 95%, respectively. The serum granulocyte colony-stimulating factor (G-CSF) was 114 pg/mL, which was elevated (normal range, < 18.1 pg/mL). After resection of the small bowel, the WBC count decreased to 20,510/mm³. The pathology showed a poorly differentiated carcinoma with sarcomatous components confirmed by positive immunostaining of cytokeratin (AE1/AE3) and vimentin in the small intestine. Furthermore, immunohistochemistry with specific monoclonal antibodies against G-CSF was positive. A lung biopsy revealed the same histological findings as the small intestine lesion. Therefore, the patient was diagnosed as having a G-C...