Performing colonic mast cell counts in patients with chronic diarrhea of unknown etiology has limited diagnostic use.

CONTEXT: Mastocytic enterocolitis is a recently described entity defined by chronic diarrhea of unknown etiology and normal colon biopsy results with increased mast cells (MCs) seen on special stains. These patients may benefit from mast cell stabilizers; however, the clinical utility of MC counts remains unknown. OBJECTIVE: To determine the clinical utility of colonic MC counts on normal biopsies in patients with chronic diarrhea of unknown etiology. DESIGN: Blinded MC counts using a c-Kit stain were performed in 76 consecutive patients with chronic diarrhea of unknown etiology who had normal colon biopsy results and in 89 consecutive control patients presenting for screening colonoscopy. Mast cells were counted per single high-power field in the highest-density area. A t test was used to compare the counts, and receiver operating characteristic curves were generated to examine sensitive and specific cutoff values. RESULTS: Overall, MC counts averaged 31 MCs per high-power field in the study group versus 24 MCs per high-power field in the control group (P < .001). When stratified by location, a significant increase was seen in biopsies from the left colon only. Receiver operating characteristic analysis revealed that overall MC counts, left-sided MC counts, and the difference between right- and left-sided MC counts did not yield discriminatory cutoff values (area under the curve, 0.68, 0.74, and 0.81, respectively). CONCLUSIONS: Mast cell counts were increased in patients with chronic diarrhea of unknown etiology, primarily in the left colon. However, receiver operating characteristic analysis demonstrates no discriminatory cutoff values. Quantitative MC stains yield little useful diagnostic information, and further studies are necessary to determine whether mastocytic enterocolitis truly represents a distinct entity.

Bleeding from a duodenal varix: a unique case of variceal hemostasis achieved using EUS-guided placement of an embolization coil and cyanoacrylate.

We report a case of a bleeding duodenal varix demonstrating excellent hemostasis achieved by endoscopic ultrasound (EUS)-directed placement of an embolization coil followed by cyanoacrylate. A 31-year-old man with decompensated Child's class C cirrhosis presented with hematemesis. An initial endoscopy revealed an actively bleeding duodenal varix. Subsequent attempt at hemostasis with ethanolamine oleate injection failed. A later attempt at hemostasis involving EUS-guided placement of an embolization coil followed by cyanoacrylate injection into the varix was successful. We reviewed the literature involving the treatment of bleeding ectopic varices and conclude that EUS provides a unique and advantageous modality for achieving variceal hemostasis of duodenal varices in patients who are not candidates for transjugular intrahepatic portosystemic shunt.

L-[1-(13)C] phenylalanine breath test for monitoring hepatic function after living donor liver transplant surgery.

Although metabolic response after partial hepatectomy has been well studied in animal models, there are few studies examining restoration of metabolic capacity after right hepatectomy in humans. The L-[1-(13)C]-phenylalanine breath test (PBT) is a simple non-invasive diagnostic tool which allows measurement of liver functional reserve. We investigated the PBT for monitoring hepatic function in living liver donors by measuring the metabolism of L-[1-(13)C]-phenylalanine ((13)C-Phe). We used (13)C-Phe administered orally and iv to adult living liver donor patients and measured exhaled (13)CO(2) to determine the extent of metabolic impairment and time course of its return. Patients given oral (13)C-Phe had approximately 70-90% reduction in (13)CO(2) production compared with baseline 2-3 days after surgery. Patients given iv (13)C-Phe had only 40-50% reduction in (13)CO(2) production and recovered their baseline (13)C-Phe metabolism much sooner than their oral (13)C-Phe metabolic capacity (P < 0.05). In some cases oral (13)C-Phe did not recover to baseline for as long as 56 days after surgery. Patients recovering (13)C-Phe metabolism had significantly higher (13)CO(2) recovery 60 min after ingestion by day 4 (0.97 versus 3.06, P = 0.033) and day 7 (1.50 versus 5.02, P = 0.031). We conclude that orally administered amino acids may not be well absorbed and/or metabolized in some subjects for weeks after partial hepatectomy whereas intravenously delivered substrates are much better oxidized by the regenerating liver. These findings may be due to impaired gut motility due to trauma to the gastrointestinal tract or portal venous flow that reduces delivery of oral agents after liver surgery. In early recovery phase for living liver donor patients, the iv PBT would be a better predictor of functional hepatic reserve.