McKittrick–Wheelock syndrome

Abstract

A 58-year-old woman presented to the emergency department. She had been vomiting and feeling confused for three days, and she had fallen several times.Three months before her presentation, the patient had been admitted to the intensive care unit at another hospital for profound dehydration, acute kidney injury (creatinine 690 [normal 61.9-115] μmol/L) and a serum sodium level that the laboratory had reported as "undetectable." Under the direction of a nephrologist, the patient's metabolic abnormalities were corrected to near-normal values with intravenous administration of fluids.The patient's medical history included rectal prolapse of two years' duration and a worsening, clear rectal discharge of four years' duration. The discharge had become so profuse that she required wearing adult briefs 24 hours each day. She had previously undergone evaluation by a general surgeon and urogynecologist. A flexible sigmoidoscopy performed one year before her current presentation was of limited quality owing to stool and liquid in the rectum but was reported as "grossly normal to 10 cm."On physical examination, the patient was alert and oriented, but her verbal responses were delayed. She had a laceration and ecchymosis over the forehead. Her vital signs were as follows: blood pressure 97/54 mm Hg, heart rate 70 beats/min, respiratory rate 18 breaths/min, oxygen saturation 97% on room air, body temperature 36.3°C), and her jugular venous pulse was not visible above the clavicle. Cardiovascular, respiratory and neurologic examinations werenormal. An examination of the patient's perianal region showed copious leakage of a clear, colourless fluid, but no other abnormalities were identified. On digital examination, however, a soft, fleshy mass 4-5 cm in diameter was palpated.Laboratory investigations identified hyponatremia ( The patient's serum sodium was slowly corrected over the next 60 hours (Appendix 1, available at www.cmaj.ca/lookup/suppl/doi:10.1503/ cmaj .141195 /-/DC1). We performed a flexible sigmoidoscopy, which identified a massive rectal lesion at 5 cm that could not be bypassed with the colonoscope (Figure 1). Multiple biopsy samples were taken, and pathology identified a tubulovillous adenoma with no evidence of highgrade dysplasia. A computed tomography scan of the abdomen and pelvis showed a large frondlike rectosigmoid tumour, with transient intussusception into the lower rectum and no clear radiographic evidence of extramural invasion (Figure 2). The patient was taken to the operating room where an open, low-anterior resection with coloanal anastomosis and a defunctioning loop ileostomy was performed. Surgical pathology identified a 10.7-cm obstructing tumour located below the peritoneal reflection. Most of the tumour comprised tubulovillous adenoma, but multiple foci of high-grade dysplasia and a single focus of invasion into the submucosa were seen. One of 27 lymph nodes resected with the specimen was positive for adenocarcinoma. Therefore, the final pathologic diagnosis was rectal adenocarcinoma.

Síndrome de McKittrick-Wheelock. Una causa infrecuente de hipokalemia e injuria renal aguda. Caso clínico

“…El tratamiento inmediato del SMKW consiste en la hidratación y reposición de electrolitos, para corregir la hipovolemia y alteraciones metabólicas; y posteriormente la resección del tumor. Para esto último se ha empleado la cirugía abierta, laparoscópica y endoscópica, así como la radioterapia endocavitaria, la que se asocia a una mayor tasa de recurrencia 2,3 . En los pacientes que no aceptan o toleran la cirugía, se ha empleado con éxito variable el uso de antiinflamatorios no esteroidales (mayoritariamente indometacina), inhibidores de la COX-2 y análogos de la somatostatina 3,9 .…”

“…En 30% de los pacientes en que se efectúa el procedimiento con este fin, se encuentran uno o varios adenomas, a menudo de pocos milíme-tros de diámetro, que suelen ser asintomáticos 2 . De acuerdo a su estructura histológica se clasifican en adenomas tubulares, túbulo-vellosos y vellosos 2 , los cuales tienen asociado un potencial de malignidad según el tamaño de estos. En 2 a 3% de los adenomas vellosos, habitualmente de varios centímetros, localizados en recto o recto-sigmoides, se produce hipersecreción de un contenido mucoso rico en electrolitos pudiendo ocasionar el síndrome de McKittrick-Wheelock (SMKW) 2 .…”

“…De acuerdo a su estructura histológica se clasifican en adenomas tubulares, túbulo-vellosos y vellosos 2 , los cuales tienen asociado un potencial de malignidad según el tamaño de estos. En 2 a 3% de los adenomas vellosos, habitualmente de varios centímetros, localizados en recto o recto-sigmoides, se produce hipersecreción de un contenido mucoso rico en electrolitos pudiendo ocasionar el síndrome de McKittrick-Wheelock (SMKW) 2 . Este consiste en una diarrea crónica de alto volumen (a veces sobre 4 litros diarios) que lleva a deshidratación, hipokalemia marcada, hiponatremia, hipocloremia, acidosis metabólica e injuria renal aguda, y frecuentemente puede producir shock hipovolémico e hipoproteinemia 1,3 .…”

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“…It is defined by the triad of electrolyte disorders, kidney injury secondary to fluid depletion and chronic secretory diarrhea caused by a large rectal neoplasm [1][2][3][4][5][6][7][8][9][10]. Renal adaption and increased oral intake may initially compensate for the fluid and electrolyte losses.…”

“…Proportional to the size, these secretory polyps can produce an abundant amount of rectal discharge and consequentially can cause hypovolemia, renal insufficiency and profound electrolyte disturbances. This rare disorder is known as the McKittrick-Wheelock syndrome (MWS) [1][2][3][4][5][6][7][8][9][10]. Treatment is initially based on volume resuscitation and on correction of the electrolyte disturbances.…”