A 54-year-old man comes to the office due to morning facial puffiness and bilateral leg swelling. His other medical problems include recurrent pulmonary infections due to bronchiectasis and psoriasis. Blood pressure is 143/92 mm Hg and pulse is 92/min. BMI is 24 kg/m². Examination shows a fourth heart sound. Hepatomegaly, palpable kidneys, and 2+ pitting edema of the lower extremities to the knees bilaterally are present on examination. Urinalysis shows 4+ proteinuria and normal urinary sediment. Which of the following is the most likely diagnosis in this patient?

Question

Quizplus · Accepted Answer

11ec25c8_d115_db7f_bc81_391812f6cb15_MD0003_00 This patient's clinical presentation of facial swelling, bilateral lower-extremity edema, and massive proteinuria are consistent with nephrotic syndrome. A common unifying diagnosis is secondary amyloidosis (AA) given the presence of nephrotic syndrome with palpable kidneys (from amyloid infiltration), hepatomegaly, and ventricular hypertrophy (suggested by an audible fourth heart sound) in the setting of chronic inflammatory disease (bronchiectasis, psoriasis). Although cardiac involvement is more common in light chain amyloidosis (AL), it can be seen in AA amyloidosis. AA amyloidosis often develops in the setting of chronic inflammatory diseases (eg, rheumatologic diseases) because serum amyloid A protein is an acute phase reactant. The diagnosis is confirmed with the presence of amyloid on tissue biopsy (eg, fat pad). Renal biopsy can be considered if fat pad biopsy is nondiagnostic. Histology demonstrates amorphous hyaline material that stains with Congo red. Treatment is usually directed at the underlying inflammatory disease (eg, bronchiectasis). (Choice B) Hepatorenal syndrome refers to acute renal failure in patients with acute or chronic liver disease and portal hypertension. It usually presents in patients with severe liver disease with progressively rising serum creatinine with minimal proteinuria (<500 mg/day). (Choice C) Hypertensive nephrosclerosis is seen in patients with chronic hypertension and is associated with retinopathy, left ventricular hypertrophy, progressive renal failure, and mild proteinuria (generally <1 g/day). Kidneys are usually small, and hepatomegaly is not present. (Choice D) IgA nephropathy is a type of nephritis that typically presents with hematuria on urinalysis. Unlike in this patient, IgA nephropathy is usually restricted to the kidneys. (Choice E) Patients with polycystic kidney disease typically present with flank pain, hematuria, renal failure, hypertension, and large palpable kidneys. Hepatomegaly can also be present due to co-occurrence of hepatic cysts in some patients. Although proteinuria is common, overt nephrotic syndrome (as seen in this patient) would be atypical. Educational objective: Secondary amyloidosis is a complication of a chronic inflammatory condition (eg, chronic infections, inflammatory bowel disease, rheumatoid arthritis) resulting in extracellular tissue deposition of fibrils into tissues and organs. Patients can develop multi-organ dysfunction (eg, kidneys, liver, gastrointestinal tract). Treatment usually involves treating the underlying inflammatory disease. References: AA amyloidosis: basic knowledge, unmet needs and future treatments. (http://www.ncbi.nlm.nih.gov/pubmed/22653707)

A 54-Year-Old Man Comes to the Office Due to Morning