WBR0927
| Author | [[PageAuthor::Twinkle Singh, M.B.B.S. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Gastrointestinal, SubCategory::Musculoskeletal/Rheumatology |
| Prompt | [[Prompt::A 50 year old male presents with complaints of diffuse abdominal pain and diarrhea which is not associated with blood. He also suffers from joint pains, weight loss and decreased night vision over the past few months. Physical examination shows inflammation at the angle of mouth, loss of papillae on tongue, generalised lymphadenopathy and diffuse hyperpigmentation of skin. Fecal occult blood test is positive in this patient. ELISA is negative for HIV antibodies. What is the characteristic finding on intestinal biopsy in this patient?]] |
| Answer A | AnswerA::Crypt abscesses |
| Answer A Explanation | AnswerAExp::Crypt abscesses are the feature of ulcerative colitis which is an inflammatory bowel disease and characterized by bloody diarrhea, tenesmus and weight loss. However, diffuse lymphadenopathy and hyperpigmentation are not present. |
| Answer B | AnswerB::PAS positive acid fast macrophages |
| Answer B Explanation | AnswerBExp::PAS positive, acid fast macrophages can be found in HIV infection, as a result of opportunistic infection caused by mycobacterium avium intracellulare. |
| Answer C | AnswerC::PAS positive non acid fast macrophages |
| Answer C Explanation | AnswerCExp::Intestinal infiltration by T. Whipplei causes PAS positive macrophages which are non acid fast. |
| Answer D | AnswerD::Diffuse lymphocytic infiltration |
| Answer D Explanation | AnswerDExp::Diffuse lymphocytic infiltration is the characteristic of intestinal lymphoma |
| Answer E | AnswerE::Normal mucosa |
| Answer E Explanation | AnswerEExp::Duodenal biopsy in Whipple's disease reveals presence of non acid fast PAS positive macrophage inclusions (foamy macrophages). Changes in mucosa seen on endoscopy are yellow shaggy mucosa with erythematous eroded patches. |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::This is a case of Whipple's disease which is a rare systemic infection caused by gram +ve bacillus Tropheryma whipplei. Most common clinical presentations include weight loss, diarrhoea, malabsorption symptoms, non deforming arthritis and generalised lymphadenopathy. It is also known to involve myocardium and nervous system frequently. Duodenal biopsy shows PAS positive inclusions in macrophages, however, the most specific test is PCR. Educational Objective: |
| Approved | Approved::No |
| Keyword | WBRKeyword::Whipple's disease, WBRKeyword::foamy macrophages |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |