A 78-year-old Caucasian male presented to the emergency department with complaints of persistent loose stools for the past 2 weeks associated with vague diffuse abdominal pain, loss of appetite and 15 pounds weight loss during the same period of time. Physical examination was unremarkable. Laboratory data was significant for a white blood cell (WBC) count greater than 40,000/mm³ with 94% neutrophils and acute kidney injury (AKI) with a creatinine of 2.6 mg/dL. Initial investigations including blood cultures, stool studies (leukocytes, electrolytes, culture, clostridium difficile, ova/parasites, fecal occult blood) and celiac disease panel were unremarkable. Evaluation of AKI with a renal ultrasound revealed 4x3x3 centimeter hypoechoic mass in the mid to upper pole of the right kidney. With gradual resolution of AKI post intravenous hydration, a computed tomography abdomen with contrast showed a solid heterogeneous mass suggestive of RCC, with subsequent biopsy revealing high grade neoplasm with sarcomatoid features. For further evaluation of diarrhea and leukocytosis, a bi-directional scope and bone marrow biopsy were performed respectively, which were unrevealing. Leukocyte alkaline phosphatase and granulocyte colony stimulating factor (G-CSF) were markedly elevated, suggestive of leukemoid reaction as a paraneoplastic syndrome of RCC. Eventually, patient underwent a right radical laparoscopic nephrectomy with complete resolution of symptoms and leukocytosis further confirming the paraneoplastic process.
Renal cell carcinoma (RCC) continues to present a diagnostic and therapeutic challenge. The propensity of RCC to manifest with diverse and obscure signs and symptoms has led to its being labeled as the internist’s tumor. A paraneoplastic syndrome is an abnormality associated with a tumor present at a distant site. It resolves with removal or control of the tumor and returns with its recurrence. RCC is unique amongst malignancies as 10-40% of patients show signs and symptoms of paraneoplastic syndromes. Severe neutrophilia caused by sarcomatoid RCC secreting G-CSF is a rare manifestation, and may be an indicator of disease activity as well as signifying poor prognosis.
It is important to keep in mind the sarcomatoid possibility of the tumor origin when there is an unknown etiology of leukocytosis, especially when infection is not likely. RCC was also found during work up for diarrhea, which completely resolved with surgery. Isolated cases have been reported in literature of a diarrhea syndrome in RCC, possibly due to the production of prostaglandins and vasoactive intestinal peptides. In conclusion, the initial presentation of RCC may be diarrhea, and although rare, physicians should consider this possibility once common causes are ruled out.
To cite this abstract:Jaffari F, Basit A, Rizvi N, Rajput F. A Challenging Presentation of the Internist’s Tumor. Abstract published at Hospital Medicine 2015, March 29-April 1, National Harbor, Md. Abstract 547. Journal of Hospital Medicine. 2015; 10 (suppl 2). https://www.shmabstracts.com/abstract/a-challenging-presentation-of-the-internists-tumor/. Accessed April 4, 2020.