title: Kidney Involvement in Systemic Calcitonin Amyloidosis Associated With Medullary Thyroid Carcinoma.
abstract: A 52-year-old woman with widely disseminated medullary thyroid carcinoma developed nephrotic syndrome and slowly decreasing kidney function. A kidney biopsy was performed to differentiate between malignancy-associated membranous glomerulopathy and tyrosine kinase inhibitor-induced focal segmental glomerulosclerosis. Surprisingly, the biopsy specimen revealed diffuse glomerular deposition of amyloid that was proved to be derived from the calcitonin hormone (Acal), produced by the medullary thyroid carcinoma. This amyloid was also present in an abdominal fat pad biopsy. Although local ACal deposition is a characteristic feature of medullary thyroid carcinoma, the systemic amyloidosis involving the kidney that is presented in this case report has not to our knowledge been described previously and may be the result of long-term high plasma calcitonin levels. Our case illustrates that systemic calcitonin amyloidosis should be considered in the differential diagnosis of proteinuria in patients with medullary thyroid carcinoma.
authors.affiliation: Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, the Netherlands. Electronic address: t.koopman@umcg.nl.
authors.forename: Timco
authors.initials: T
authors.lastname: Koopman
authors.affiliation: Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Cindy
authors.initials: C
authors.lastname: Niedlich-den Herder
authors.affiliation: Department of Internal Medicine, Division of Nephrology, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Coen A
authors.initials: CA
authors.lastname: Stegeman
authors.affiliation: Department of Internal Medicine, Division of Endocrinology, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Thera P
authors.initials: TP
authors.lastname: Links
authors.affiliation: Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Johan
authors.initials: J
authors.lastname: Bijzet
authors.affiliation: Department of Rheumatology and Clinical Immunology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Bouke P C
authors.initials: BPC
authors.lastname: Hazenberg
authors.affiliation: Department of Pathology and Medical Biology, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Arjan
authors.initials: A
authors.lastname: Diepstra
mesh_terms: D050153:Abdominal Fat / Q000473:pathology; D000686:Amyloidosis / Q000473:pathology*; D001706:Biopsy; D002116:Calcitonin / Q000378:metabolism*; D018276:Carcinoma, Medullary / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006729:Hormones, Ectopic / Q000378:metabolism*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000473:pathology*; D007678:Kidney Glomerulus / Q000473:pathology*; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000473:pathology; D058225:Plaque, Amyloid / Q000473:pathology*; D011507:Proteinuria / Q000473:pathology; D013964:Thyroid Neoplasms / Q000473:pathology*
chemical_list: D006729:Hormones, Ectopic; D002116:Calcitonin
keywords: Calcitonin amyloid (ACal); amyloid-associated glomerulopathy; case report; decreased kidney function; kidney amyloidosis; medullary thyroid carcinoma; nephrotic syndrome; proteinuria; renal biopsy; systemic amyloidosis