We present the case of a man in his 70s who was referred to gastroenterology with several months’ history of offensive smelling loose stools and weight loss. He underwent a standard panel of initial investigations including colonoscopy for his chronic diarrhoea. Colonoscopy was reported as normal and the results of the rest of his screening panel were unremarkable. As his symptoms persisted, lower GI endoscopy was repeated. This showed a few scattered diverticula and some possible left colonic mucosal congestion, but biopsies were reported as within normal limits (see figure 1).
Figure 1.
H&E stain of colonic biopsy.
Concurrently, the patient started developing exertional breathlessness. Blood tests did not reveal any renal dysfunction. Chest X-ray revealed bilateral pleural effusions and subsequent echocardiography showed mild to moderate concentric left ventricular hypertrophy (LVH) (see figures 2 and 3), the myocardium of interventricular septum appears speckled and overall systolic function was mildly impaired
Figure 2.
Echocardiogram.
Figure 3.
Echocardiogram.
Q1
Can you think of a unifying diagnosis?
Q2
What other stain you might ask for?
Answer
The echocardiographic finding of unexplained LVH should raise possibility of cardiac amyloidosis. He subsequently had cardiac MRI, which reported concentric LVH and late gadolinium enhancement was suggestive of an infiltrative cardiomyopathy in keeping with cardiac amyloidosis (figures 4 and 5). He was being planned for cardiac biopsy, when his colonic biopsies were reviewed for GI Amyloid. Congo red stained amyloid deposits in his colonic biopsies a deep orange (figure 6), which demonstrated apple-green birefringence under polarised light (figure 7). Diagnosis was GI and cardiac amyloidosis and further testing at the National Amyloidosis Centre confirmed AL amyloidosis.
Figure 4.
Cardiac MRI revealed concentric LVH and late gadolinium enhancement was suggestive of an infiltrative cardiomyopathy most likely amyloid. LVH, left ventricular hypertrophy.
Figure 5.
Cardiac MRI revealed concentric LVH and late gadolinium enhancement was suggestive of an infiltrative cardiomyopathy most likely amyloid. LVH, left ventricular hypertrophy.
Figure 6.
Colonic biopsy stained with Congo red demonstrating deep orange deposits of amyloid.
Figure 7.
Apple green birefringence of the amyloid deposits under polarised light.
AL amyloidosis is the most common type. It can be multisystemic, with variable clinical presentation and very much dependent on specific organ involvement. Cardiac involvement does appear to be increasing with an estimated incidence of 16.6 patients per 100 000 person-years1 and should be suspected in patients with otherwise unexplained heart failure.
Amyloidosis remains underdiagnosed although there are therapeutic options available, which can improve length and quality of life.2 As symptoms are often non-specific, GI amyloid is not high on a gastroenterologist’s list of differential diagnoses. Given the suspected higher prevalence of the condition, perhaps there is an argument to investigate earlier, especially in patients with multi-system involvement.
Footnotes
Contributors: TM assessed the patient in clinic, diagnosed with GI amyloidosis and consented the patient for this publication. KJA has written the manuscript, liaised with relevant specialities, presented in local medical unit meeting and submitted for publication. CW has supervised and contributed to writing the manuscript. Images have been contributed by histopathology and cardiology (echocardiography) departments at Countess of Chester hospital. KJA and TM are responsible for the overall content as guarantors.
Funding: The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests: None declared.
Provenance and peer review: Not commissioned; externally peer reviewed.
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References
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