Abstract
Gastrointestinal amyloidosis is a rare but often a manifestation of an advanced form of systemic amyloidosis that carries a poor prognosis. Its presentation may mimic ischemic bowel disease, inflammatory bowel disease, celiac disease, or protein-losing enteropathy, among others. Often, varied presentations make it difficult to diagnose. Hence, a careful and systematic approach with an aggressive treatment strategy is needed for prompt diagnosis and treatment of the fatal condition. Here, we report a fatal case of systemic amyloidosis (amyloid light-chain (AL) amyloidosis) with its initial presentation including gastrointestinal symptoms and subsequent rapid clinical deterioration due to worsening renal function and evidence of pericardial effusion.
Introduction
Amyloidosis is a rare disorder characterized by the deposition of misfolded amyloid proteins, which can occur in systemic or localized forms. It can be classified into major systemic types, including amyloid light-chain (AL) amyloidosis (associated with plasma cell dyscrasia), amyloid A amyloidosis (AA) (associated with chronic inflammatory disorders), and transthyretin amyloidosis (ATTR) (associated with cardiac and neurologic involvement), as well as localized or organ-specific types such as atrial natriuretic factor amyloidosis (isolated atrial) and Acal amyloidosis (calcitonin‑related). Approximately 3% of patients with amyloidosis have gastrointestinal (GI) involvement. Depending on the site of production and deposition of the amyloidogenic precursor proteins, the disease may be limited to the GI tract as a localized process or represent part of systemic involvement [1]. Because of its variable and nonspecific manifestations, including acid reflux, abdominal pain, bloating, GI bleeding, diarrhea, nausea, vomiting, dysphagia, and pseudo-obstruction, diagnosis can be challenging [1-3]. More than half of patients may present with GI bleeding due to ischemia, ulcers, erosions, or submucosal hematomas [4,5]. As a result, these patients often undergo extensive diagnostic evaluation, which can delay recognition of the underlying condition. The clinical presentation and prognosis depend on the location, quantity, and type of amyloid protein deposition. Here, we describe a rare case of biopsy‑proven AL amyloidosis that initially presented with lower GI bleeding, highlighting the diagnostic challenges and the importance of tissue-based confirmation.
Case Presentation
A 75-year-old male presented to the emergency room with painful rectal bleeding. His past medical history was significant for diverticulosis, thoracic myelopathy due to a T12-L1 lesion, hypertension, type II diabetes mellitus, and hypothyroidism. He denied any prior history of intra-abdominal surgeries. The patient had developed diarrhea and abdominal cramping three days before presentation. He had also been experiencing progressive fatigue and shortness of breath with exertion for the past couple of months before presentation. His physical examination was unremarkable except for positive stool guaiac testing performed at the bedside. Laboratory work was significant for elevated creatinine with nephrotic-range proteinuria. CT of the abdomen and pelvis revealed diffuse wall thickening with mild pericolonic fat stranding involving the splenic colonic flexure, concerning for acute ischemic colitis (Figure 1). During hospitalization, the patient received supportive care for the management of colitis and acute kidney injury. The patient underwent a colonoscopy, which revealed segmental ulceration with surrounding mucosal edema and blood clots, particularly in the hepatic and splenic flexures, concerning for ischemic colitis. Additionally, incidental diverticulosis of the sigmoid colon was noted (Figure 2). Biopsy results revealed findings consistent with the diagnosis of amyloidosis, indicating AL (kappa-type) amyloid deposition as confirmed by the Congo red stain (Figure 3). Detailed biopsy results are presented in Table 1. The patient was subsequently referred to the hematology/oncology service. Further workup, including serum and urine protein electrophoresis, echocardiogram, bone marrow and fat pad biopsy (Table 1) was performed, and he was diagnosed with AL-type amyloidosis with systemic involvement characterized by pericardial effusion causing cardiac and renal failure (Mayo Stage Stage IV, Cardiac Stage 3b).