S1973 A Rare Case of McKittrick Wheelock Syndrome

Abstract

Introduction: McKittrick Wheelock Syndrome (MWS) is a rare disorder characterized by distal colorectal tumors, most commonly benign secretory villous adenoma leading to secretory diarrhea with electrolyte depletion syndrome. Patients present with volume depletion, severe electrolyte derangement, specifically hyponatremia and hypokalemia, along with acute kidney injury (AKI). We present a rare case of an elderly female with severe electrolyte derangement in setting of MWS. Case Description/Methods: A 71-year-old woman with history of 4 months of watery diarrhea, fatigue, and anorexia presented after a syncopal episode. Notable labs Na 114 mEq/L, K 2.2 mEq/L, WBC 23.5K, and Cr 2.91 mg/dL. Stool electrolytes resulted in Stool Osm Gap 48 mOsm/kg consistent with secretory diarrhea. Of note, patient was hospitalized 3 times in the past 2 months for hyponatremia, hypokalemia, and AKI requiring temporary dialysis secondary to profuse diarrhea. A colonoscopy revealed a large rectal polypoid lesion with pathology consistent with a tubulovillous adenoma (Figure). She had aggressive electrolyte and fluid repletion with a robot assisted abdominoperineal resection. Subsequently, noted to have resolution of her symptoms and complete electrolyte correction upon follow up (Table). Discussion: Villous adenomas, normally a benign condition, can present with a life-threatening electrolyte derangements and volume depletion which makes the ability to diagnose and adequately treat MWS critical. Patients typically have multiple admissions with watery or mucous diarrhea, nausea, and vomiting. Labs significant for hyponatremia, hypokalemia, AKI, and leukocytosis. The tumors are large and often past the splenic flexure and low in the rectum, therefore flexible sigmoidoscopy can be reliably used rather than colonoscopy, which often delays diagnosis due to patients’ inability to prep. Treatment includes aggressive fluid and electrolyte repletion until tumor can be surgically resected. Few case reports suggest using indomethacin or octreotide as a bridge to surgery or as medical management for patients who are not surgical candidates. However, patients who are managed medically have a mortality rate up to ∼61-100%. Surgical management to definitively resolve symptoms, although minimally invasive options are being explored. A high index of suspicion and a systematic approach is critical to diagnose and provide life-saving treatment for MWS patients. Table 1. - Electrolytes: Comparison of Initial Admission vs. Post-Surgical Resection Electrolytes Initial Admission Post-surgical Resection Na 114 137 K+ 2.2 4.8 Cl 79 106 Creatinine 2.91 1.06 Figure 1.: Large rectal polypoid lesion with pathology consistent with a tubulovillous adenoma.