Nocardia farcinica pituitary abscess in an immunocompetent patient: illustrative case.

Background: Pituitary abscess is a rare clinical entity, typically precipitated by Staphylococcus, Pseudomonas, or Aspergillus infection. Although Nocardia species-associated central nervous system abscesses have been documented in immunocompromised patients, no case of Nocardia pituitary abscesses has been previously reported.

Observations: A 44-year-old man presented with hemoptysis and was found to have a cavitary right lung nodule, which was presumed histoplasmosis, prompting antifungal treatment. Several months later, he developed panhypopituitarism. Magnetic resonance imaging identified a pituitary mass, which subsequently underwent transsphenoidal endoscopic biopsy. Infectious workup was negative, and the patient was discharged on intravenous ertapenem therapy. Over several months, he developed progressive headaches, and updated imaging confirmed interval enlargement of the mass with new cavernous sinus invasion. He underwent repeat endoscopic biopsy, which yielded positive cultures for Nocardia farcinica and prompted successful treatment with trimethoprim-sulfamethoxazole and linezolid.

Lessons: The current study highlights a previously unreported clinical entity, the first pituitary abscess attributable to Nocardia sp. or N. farcinica, which arose in a young, immunocompetent individual. Although rare, atypical infections represent an important component in the differential diagnosis for sellar mass lesions.