Abdominal case of the day. Neutropenic enterocolitis associated with acute leukemia.

A 27-year-old man who had recently had acute leukemia diagnosed was hospitalized for induction chemotherapy. One and a half weeks after starting treatment, he had nausea, abdominal pain, watery diarrhea, and fever. Physical examination elicited exquisite tenderness in the night lower quadrant and revealed a single loop of distended bowel. No signs indicating penitoneal irritation were present. Laboratory values revealed profound neutnopenia. Blood cultures were done. Broad spectrum antibiotic coverage was empirically instituted. Findings on a plain film of the abdomen were nonmal (Fig. 1). Sonognaphy, performed to exclude acute appendicitis, showed the cecum and the terminal part of the ileum to be thickened and echogenic. The findings were interpreted as evidence of typhlitis. Further support for this diagnosis was obtained by CT: the cecum, ascending colon, and ileum were thick walled with an associated inflammatory reaction in the adjacent fat. No localized fluid collections on abscesses were seen. The patient’s management remained conservative. Surgery was avoided. Twelve days later, after the symptoms had resolved, he was discharged. Typhlitis is an important and often life-threatening complication in severely immunocompnomised patients, typically those undergoing cytotoxic therapy for hematologic malignant neoplasms. Although the term typhlitis reflects a pnedilection for cecal inflammation, the lesions may extend beyond the cecum to involve variable segments of small bowel and ascending colon [1 , 2]. Consequently, more precise, alternative terms such as neutropenic on necrotizing entenocolitis may actually better localize and describe the underlying entenic complications. The cause of neutnopenic entenocolitis is multifactonial. Essentially, it is a cycle in which the integrity of the colonic mucosa is disturbed, allowing secondary intramural invasion by opportunistic resident microflona [1]. Absence of a granulocytic response facilitates this bacterial proliferation. The findings are always most florid in the cecum. Several mechanisms of mucosal damage have been proposed [1-4]. Ulceration is thought to anise from ischemia related to cytotoxic drug-induced cecal stasisand distension,submucosal hemonrhage, leukemic infiltration, or direct drug toxicity on the mucosa. The resultant ulcers may become confluent. The predominant pathologic changes are mucosal and submucosal. Submucosal hemorrhage, edema, and necrosis are almost always present [1 , 2, 4]. If left unchecked, tnansmural extension and perforation may develop [3]. Affected patients are invariably neutropenic. Their signs and symptoms may include fever, nausea, abdominal pain, and watery on bloody diarrhea [1-4]. With time, the abdominal pain may localize to the night lower quadrant, and signs of septicemia on peritonitis may emerge [3]. In the appnopniate clinical setting, nadiologic studies can aid in clarifying on confirming a suspected diagnosis of typhlitis. The value of CT [5, 6] and sonognaphy [7, 8] in the detection and diagnosis of neutropenic enterocolitis has been reported by several authors. CT may show a diffusely thickened cecum and ascending colon. Many of the adjacent fascial planes also may be thickened. The colonic wall itself often is homogeneously thickened but may contain areas of decreased attenuation, reflecting underlying edema and necrosis. Localized collections of extnaluminal fluid may be present. In contrast to CT, it has been suggested that the sonognaphic appearance of typhlitis is characteristic [8]. When the mucosa in the cecum is redundant and thickened in an echogenic fashion, it is thought to be typical. Cases in which the mucosa is thickened but hypoechoic have also been reported. Most cases are managed conservatively with prophylactic bowel rest, broad spectrum antibiotic coverage, and gnanulocytic support [3, 4]. Surgical intervention has been promoted in the event of cecal perforation, abscess formation, massive gastrointestinal bleeding, uncontrolled sepsis, or obstruction [3]. Once thought to be uniformly fatal, neutnopenic entenocolitis remains a serious but treatable complication in the neutropenic patient. Prompt recognition is critical. The clinical picture may be confusing in these patients. Symptoms referable to the night lower quadrant elicit a wide variety of possible causes. The detection of a thickened cecum on CT scans or sonognams together with suggestive clinical featunes should facilitate the diagnosis of neutropenic enterocolitis and avoid unnecessary surgery.