To preserve patient privacy and for didactic purposes, case descriptions and pathology reports have been anonymized and partially fictionalized. The pathology images are representative images from a mixture of similar cases.

Invited Speakers

Malvinder Parmar
Malvinder ParmarCase Presenter | Northern Ontario School of Medicine, Ontario, Canada | No conflict of interest reported
Helmut Rennke
Helmut RennkeNephropathology Discussant | Brigham Women's Hospital, Boston, MA, USA | No conflict of interest reported
Adam Segal
Adam SegalNephrology Discussant | Atrius, Boston, MA, USA | No conflict of interest reported

Case

Patient is a 45-year-old man who has been feeling tired with decreased energy level for almost 1 year.

Elevated TSH was noted 3-months ago, and patient started on thyroid replacement, and statin for hyperlipidemia.

Patient continued to feel tired, experiencing decreased exercise tolerance and noted some ankle swelling for past few months. Rural clinic working diagnosis – “CHF”. At the time of consult noted 1-2+ lower extremity edema. On further questioning admits to ‘foamy urine’ for 5-6 months. No history of joint pains, stiffness, skin rashes, weight loss, fever, chills or night sweats. No history of gross hematuria or NSAID use

Medical history:
Gastro-esophageal reflux disease
History of squamous cell cancer
Bilateral carpal tunnel release
Current smoker

Medications:
Pantoprazole
L-thyroxine
Rosvustatin

Laboratory and other data:
Normal white and red blood cell count
Serum creatinine 70 umol/L (eGFR 75),
Serum albumin 33 g/L.
HbA1C, ANA, C3, IgG, anti-HCV, HBsAg requested.
Uric acid Normal at 229 (149-369 umol/L),
Serum calcium 2.30 (2.10-2.55 mmol/L)
ANA – Negative, C3 1.41, APLA- Negative
Anti-HCV – Negative, HBsAg – Negative
Serum immuno-electrophoresis: monoclonal IgG lambda band
Low Total IgG 1.4 (6.00- 16.00 g/L)
ESR 40 cm
CRP 0.7
Urinalysis showed 3+ protein, trace of blood,
24-hr Urine protein 12.4 g/day
Echocardiogram: Normal myocardial function
Stress test: negative for ischemia

Kidney Pathology

Pathology images pending

15% of glomeruli globally sclerosed. No increase in mesangial matrix or cellularity, no segmental scars, patent glomerular capillaries, normal walls, few glomeruli show prominent podocytes with foamy cytoplasm.

On IF: Linear staining for lambda in capillary loops. On EM: The mesangium and glomerular BM contain non-branching, randomly arranged fibrils with diameter from 9 to 12 nm, c/w amyloid.

Questions posed & summary of key discussion points

1. Any additional work up at this point?
2. What are the therapeutic options considering the potential diagnosis?

Author(s) of case summary:

Case summary pending

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