Amyloidosis of the gastrointestinal tract and the liver: clinical context, diagnosis and management

Amyloidosis is a group of disorders that can manifest in virtually any organ system in the body and is thought to be secondary to misfolding of extracellular proteins with subsequent deposition in tissues. The precursor protein that is produced in excess defines the specific amyloid type. This requires histopathological confirmation using Congo red dye with its characteristic demonstration of green birefringence under cross-polarized light. Gastrointestinal (GI) manifestations are common and the degree of organ involvement dictates the symptoms that a patient will experience. The small intestine usually has the most amyloid deposition within the GI tract. Patients generally have nonspecific findings such as abdominal pain, nausea, diarrhea, and dysphagia that can often delay the proper diagnosis. Liver involvement is seen in a majority of patients, although symptoms typically are not appreciated unless there is significant hepatic amyloid deposition. Pancreatic involvement is usually from local amyloid deposition that can lead to type 2 diabetes mellitus. In addition, patients may undergo either endoscopic or radiological evaluation; however, these findings are usually nonspecific. Management of GI amyloidosis primarily aims to treat the underlying amyloid type with supportive measures to alleviate specific GI symptoms. Liver transplant is found to have positive outcomes, especially in patients with specific variants of hereditary amyloidosis.

Localized amyloid in thyroid: are we missing it?

When present in thyroid, amyloid is an attribute almost always restricted to medullary thyroid carcinoma. Scant studies in the literature have demonstrated this finding in other thyroid pathologies as papillary thyroid carcinoma, amyloid goiter, and other benign entities. From our experience in thyroid pathology, we analyzed cases on which the stroma contained deposits of amorphous, acellular, and eosinophilic material characteristic of amyloid. Congo red stain on suspicious cases was performed; clinicopathologic investigation was done when results were positive. Seven patients with amyloid infiltration in the thyroid, in association with papillary thyroid carcinoma, and in 4 cases of benign pathologies were found in our own review. The association of amyloid and thyroid is discussed herein, including cases of systemic amyloidosis, malignancies, benign diseases, and thyroid goiter, from our practice and from the available literature.

Fatal gastrointestinal hemorrhage in a paraplegic man with undiagnosed AA (secondary) amyloidosis

We report a case of a 41-year-old African-American male paraplegic for more than 20 years, who had recurrent infections, renal failure with total urine protein of 840 mg/dL on urine protein electrophoresis and adrenal cortical insufficiency. He died suddenly of massive gastrointestinal (GI) hemorrhage. Autopsy showed clinically undiagnosed systemic amyloidosis involving the kidneys, adrenal cortices, spleen and small blood vessels of most organs and tissues, including those of the gastrointestinal tract. The history and autopsy findings indicated secondary or amyloid A (AA) amyloidosis. Paraplegia was one of the most common causes of secondary amyloidosis decades ago, but has now become unusual in patients with AA amyloidosis. Extensive involvement of GI small vessels was the most likely cause of fatal bleeding. GI amyloid previously has been shown to cause hemorrhage, but a fatal case has not yet been described.