A 49-year-old man presents with chronic watery diarrhea, sometimes blood-streaked, for 3 months. He also reports weight loss (7 kg), fatigue, and an intensely itchy rash on his elbows, knees, and buttocks that hasn’t responded to topical steroids. He denies recent travel, food allergies, or known IBD.
On further questioning, he mentions frequent flushing, especially after alcohol, and has recently started feeling episodes of palpitations and cramping abdominal pain.
On Examination:
- BP: 130/85 mmHg | HR: 92 bpm | Temp: 99.1°F
- Skin: Symmetrical, excoriated vesicular rash on extensor surfaces
- Abdomen: Mild tenderness in RLQ
- No hepatosplenomegaly
- Rectal exam: Occasional fresh blood
Investigations:
- CBC: Mild normocytic anemia
- ESR/CRP: Elevated
- Stool test: Occult blood +; no ova/parasites
- Anti-tTG IgA: Strongly positive
- Colonoscopy: Scattered erosions in the terminal ileum and colon
- CT Abdomen: Mild mesenteric lymphadenopathy
- Serum chromogranin A: Elevated
- Urinary 5-HIAA (24 hr): Elevated
- Skin biopsy: Subepidermal vesicles with IgA deposition at dermal papillae
-What is the most unifying diagnosis that explains the GI symptoms, rash, and hormonal features?
-What is the diagnosis of the rash, and what is it typically associated with?
-What additional imaging or testing would you do next?
-How would you manage this case both the malignancy and systemic symptoms?