An unusual cause of haematochezia

Endoscopic Findings of Small-Bowel Lesions in Familial Amyloid Polyneuropathy: A Case Report

Familial amyloid polyneuropathy (FAP) is an autosomal dominant disease associated with the mutations in the transthyretin gene. To date, the endoscopic findings of the small-bowel lesions of FAP have never been described. We report a rare case of FAP with gastrointestinal involvement. A 71-year-old woman complaining of refractory diarrhea for 1 year was referred to our institution. She had sensory disturbance, movement disorder due to muscle weakness, and autonomic nervous system disorders including orthostatic hypotension and dysuria. Her eldest sister had cardiac amyloidosis. Small-bowel radiography and retrograde double-balloon endoscopy (DBE) revealed that fine granular protrusions were diffusely observed both in the jejunum and ileum. Histologic examination of the biopsy specimens obtained from the small bowel revealed perivascular amyloid deposits mainly in the muscularis mucosae and submucosa, which were immunoreactive with transthyretin antibodies. Analysis of the genomic DNA showed a heterozygous Gly47Val mutation in the transthyretin gene. Thus a diagnosis of FAP was established. Diffuse fine granular protrusions in the jejunum and the ileum visualized by small-bowel radiography and DBE may be characteristic of FAP. Multiple biopsies from the gastrointestinal mucosa are recommended for the definitive histologic diagnosis of FAP.

Endoscopic and histopathological features of gastrointestinal amyloidosis

Amyloidosis is a rare disorder, characterized by the extracellular deposition of an abnormal fibrillar protein, which disrupts tissue structure and function. Amyloidosis can be acquired or hereditary, and systemic or localized to a single organ, such as the gastrointestinal (GI) tract. Clinical manifestations may vary from asymptomatic to fatal forms. Primary amyloidosis (monoclonal immunoglobulin light chains, AL) is the most common form of amyloidosis. AL amyloidosis has been associated with plasma cell dyscrasias, such as, multiple myeloma. Secondary amyloidosis is caused by the deposition of fragments of the circulating acute-phase reactant, serum amyloid A protein (SAA). Common causes of AA amyloidosis are chronic inflammatory disorders. Although GI symptoms are usually nonspecific, histopathological patterns of amyloid deposition are associated with clinical and endoscopic features. Amyloid deposition in the muscularis mucosae, submucosa, and muscularis propria has been dominant in AL amyloidosis, leading to polypoid protrusions and thickening of the valvulae conniventes, whereas granular amyloid deposition mainly in the propria mucosae has been related to AA amyloidosis, resulting in the fine granular appearance, mucosal friability, and erosions. As a result, AL amyloidosis usually presents with constipation, mechanical obstruction, or chronic intestinal pseudo-obstruction while AA amyloidosis presents with diarrhea and malabsorption Amyloidotic GI symptoms are mostly refractory and have a negative impact on quality of life and survival. Diagnosing GI amyloidosis requires high suspicion of evaluating endoscopists. Because of the absence of specific treatments for reducing the abundance of the amyloidogenic precursor protein, we should be aware of certain associations between patterns of amyloid deposition and clinical and endoscopic features.