Immunoassay interferences: laboratory pitfall in the diagnosis of adrenocortical carcinoma

BMJ Case Rep. 2024 Feb 10;17(2):e257320. doi: 10.1136/bcr-2023-257320.

Abstract

A woman in her late 50s with recent onset of hypertension, diabetes, lumbar pain and unintentional weight loss was diagnosed with a cortisol and androgen-producing adrenal mass. Despite this, serum adrenocorticotropic hormone (ACTH) concentration was inappropriately elevated, which was investigated thoroughly. Investigations included a brain magnetic resonance imaging to exclude concomitant pituitary adenoma, a corticotropin-releasing hormone stimulation test and a gallium-68 DOTATATE and 18F-FDOPA PET scan, both excluding ectopic ACTH production. Considering the disparity between clinical presentation and biochemical results, the ACTH was reanalysed using the Cobas immunoassay (Roche, Switzerland), ultimately unveiling the cause for ACTH elevation. ACTH levels had previously been measured with ACTH Immulite (Siemens, Germany), a two-site immunoassay which is prone to interferences causing falsely elevated ACTH concentrations. Inaccurate laboratory levels can lead to diagnosis delay and unnecessary diagnostic procedures and a close communication between the physicians and laboratorians is of utmost importance.

Keywords: Adrenal disorders; Endocrine cancer; Medical education; Surgical oncology.

Publication types

  • Case Reports

MeSH terms

  • Adrenal Cortex Neoplasms* / diagnosis
  • Adrenocortical Carcinoma* / diagnosis
  • Adrenocorticotropic Hormone
  • Female
  • Humans
  • Hydrocortisone
  • Immunoassay
  • Middle Aged

Substances

  • Adrenocorticotropic Hormone
  • Hydrocortisone