Case Presentation:
A case of malabsorption syndrome secondary to primary amyloidosis is presented here. A male in his forties presented with intermittent rectal bleeding, watery diarrhea, steatorrhea, dizziness and weight loss of 30 pounds over a year. The patient had an unremarkable medical history. On exam, he was afebrile but tachycardic and hypotensive. Tenderness was noted in the epigastric region with no palpable masses and decreased bowel sounds. Lab data revealed a hemoglobin level of 6.8 mg/dL with normal WBC and platelet counts. Coagulation studies and other routine biochemical tests were within normal ranges. Patient had an EGD and colonoscopy, which showed mild gastritis and small internal and external hemorrhoids. Further labs showed iron‐deficiency anemia, and he was treated with oral iron supplementation. The patient had several admissions for hypotension and severe anemia requiring blood transfusions over the next year. Symptoms of hematuria prompted further extensive investigations including repeat colonoscopy with biopsy, capsule endoscopy, stool studies, enteroscopy with biopsy urine 5‐HIAA, hydrogen breath tests, SPEP. and UPEP, which were all negative. A bone marrow biopsy showed increased plasma cells with predominant lambda staining. Features of malabsorption associated with autonomic neuropathy and increased plasma cells in the bone marrow forced a repeat review of the small intestine, colon, and urinary bladder pathology, which showed patchy areas of amyloid deposition confirmed by a positive Congo red stain. Primary AL amyloidosis was diagnosed, and the patient is currently being evaluated for autologous hematopoietic stem cell transplantation.
Discussion:
Amyloidosis is a rare disorder resulting from extracellular deposition of fibrillar, proteinaceous material in various tissues in a twisted beta‐pleated configuration. Amyloid light (AL) chain is found in primary or idiopathic amyloidosis, whereas amyloid A (AA) protein is found in secondary amyloidosis because of inflammatory or infectious diseases. AL amyloidosis is exceedingly rare and predominantly involves the small intestine. Gl manifestations includes mucosal erosions with severe hemorrhage, malabsorption, protein‐losing enteropathy, and intractable diarrhea. Malabsorption may be a result of mucosal infiltration or autonomic neuropathy with bacterial overgrowth. CT findings of focal or diffuse wall thickening may resemble ischemia. The mortality rate is very high, and long‐term survival is best achieved with hematopoietic stem cell transplantation. Patients who are not candidates for transplant are treated with a regimen of melphalan and dexamethasone to improve symptoms and prolong longevity.
Conclusions:
Primary systemic amyloidosis should be routinely considered during evaluation of malabsorption syndrome and the pathologist should be alerted about this possibility. Urine immunofixation and serum‐free light‐chain analysis is recommended in malab‐sorptive patients scheduled for small bowel biopsy.
Author Disclosure:
S. Subbiah, none; S. V. Iduru, none; A. Jaina, none; R. S. R. Sappati Biyyani, none.