Clinical Vignettes/Case Reports - Colon.

Abstract

Case: An 84 year old woman with a history of hypertension presented to an outpatient gastroenterology clinic for work up of watery diarrhea. Her diarrhea started one year prior, described as 5-6 loose daily non-bloody bowel movements with associated cramping. Overtime, it increased in frequency and was associated with fecal incontinence and 25 lb weight loss. Physical exam and basic laboratory testing was unremarkable. Negative work up included: EGD and colonoscopies with biopsies, MR enterography, lactulose breath test, infectious work up including stool cultures and O&P, TSH, urine 5-HIAA, VIP, calcitonin, serum gastrin and fecal elastase. Trials of various medications including rifaximin, loperamide, probiotics as well as dietary changes were ineffective. During a later admission for pneumonia, a CT chest demonstrated an incidental 5x3 cm anterior mediastinal mass suspicious for a thymoma. This prompted further laboratory testing showing undetectable levels of IgA and IgM, and decreased IgG. Given concurrent hypogammaglobulinemia and incidental finding of a suspected thymoma, her symptoms were thought to be from Good's syndrome. IVIG therapy was initiated ultimately leading to resolution of her GI symptoms; however patient refused more definitive therapy with biopsy or resection of her mass. Discussion: Good's Syndrome (GS) is a rare disease process characterized by thymoma with associated hypogammaglobulinemia first described by R.A Good in 1954. The typical presentation is characterized by recurrent infections such as bronchitis, sinusitis or GI tract infections such as giardiasis, CMV colitis or cryptosporidiosis. To our knowledge, there are a limited number of cases of chronic non-infectious diarrhea as a manifestation of GS. Although the mechanism has been debated, chronic diarrhea has been associated with hypogammaglobulinemia in diseases such as common variable immune deficiency as well as X-linked agammglobulinemia. When the initial evaluation of chronic diarrhea is unrevealing, Good's Syndrome may warrant consideration. Testing for hypogammaglobulinemia should be considered first and if present, then imaging studies can be done to evaluate for a thymoma. Early diagnosis and recognition of Good's Syndrome is important since outcomes are often poor due to risk of malnutrition, severe recurrent infections as well as hematologic complications.