Nephrotic Syndrome Following Resection of an Adrenal Incidentaloma:A Case Report

A 69 year old man had a 5 cm right adrenal lesion discovered incidentally while being investigated for a deterioration in previously well-controlled hypertension. Routine investigations including serum albumin were normal. Further investigation confirmed a non-functioning adrenal lesion. MRI revealed a ‘non-fat-containing T1 hyperintense indeterminate adrenal lesion with speckling of T2 hyperintensity, not typical for adenoma, hyperplasia, myelolipoma, haemangioma or pheochromocytoma’. An uncomplicated laparoscopic adrenalectomy was performed. Histology revealed a 118 g adrenal neoplasm, modified Weiss score 0, with abundant hyaline deposits.3 months later the patient complained of peripheral oedema. Investigations revealed a serum albumin of 24 g/L and 14 g of proteinuria in 24 hours. Serum protein electrophoresis revealed a monoclonal IgA type lambda band. Renal biopsy revealed amorphous material displaying apple green birefringence on staining with Congo Red, which stained with antibodies to lambda light chains, confirming AL amyloid. Therefore the patient’s resected adrenal specimen was retrieved and stained with Congo Red, revealing apple green birefringence in the walls of the blood vessels, confirming the presence of amyloidosis. Although adrenal gland involvement in secondary amyloidosis is common, adrenal involvement in primary amyloidosis is less well described. This case illustrates the indolent nature of primary amyloidosis, prior to the development of often catastrophic symptoms. Consideration should be given to Congo Red staining of resected pathologic specimens containing hyaline deposition, to potentially allow for earlier recognition of this devastating disease. A pathophysiologic link between the patient’s incidentaloma, adrenalectomy, and onset of nephrotic syndrome remains a matter for conjecture.