Immunoassay interferences: laboratory pitfall in the diagnosis of adrenocortical carcinoma.

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.

Multiresistent Cupriavidus pauculus infection in an immunocompromised elderly patient.

Cupriavidus pauculus is a gram-negative bacillus aerobic bacteria widely distributed in nature that can cause, in rare cases, serious infections both in immunocompromised and immunocompetent patients. We describe a case of an elderly patient admitted in emergency room with septic shock and diagnosed with a urinary tract infection. During his hospital stay, his clinical and analytical conditions have deteriorated. Blood cultures were positive for C. pauculus only sensitive to minocycline. Despite every effort, due to multiple comorbidities and a nosocomial pneumonia, the patient ends up dying.