Abstract Introduction Primary pituitary lymphoma is extremely rare but can be life-threatening. In immunocompromised patients, acute ophthalmoplegia, headache, and panhypopituitarism should raise suspicion. Differentiation from infiltrative–granulomatous diseases or opportunistic infections can be difficult, yet crucial. Here, we present a rare case of primary pituitary lymphoma in a patient with diplopia, panhypopituitarism, and newly diagnosed HIV positivity. Clinical Case A 51-year-old male presented to the emergency department with acute headache and diplopia. Neurological examination revealed restricted rightward and upward gaze and left temporal hemianopia. MRI showed a lesion adjacent to the cavernous sinus. The patient was admitted to the neurology ward and later transferred to the ICU due to clinical deterioration. Laboratory evaluation revealed hyponatremia and central hypothyroidism, leading to endocrinology consultation. Upon examination he was conscious, with intact motor function and normal systemic findings. Pituitary MRI revealed a heterogeneously enhancing sellar mass (∼25×18 mm) extending into the stalk and invading the left cavernous sinus (Figure 1). Differential diagnosis included pituitary macroadenoma, inflammatory/infectious disease, and lymphoma. Laboratory studies demonstrated panhypopituitarism (Table 1). Stress-dose steroids and levothyroxine were initiated, resulting in clinical and biochemical improvement. Further evaluation revealed HIV-RNA 387,000 CP/mL and CD4/CD8 ratio of 0.26, and the patient was referred to the Infectious Diseases Department. Extensive CSF work-up yielded negative results. Serological tests showed negative VDRL, cryptococcal antigen, and Brucella antigen, but positive total syphilis antibody and TPHA, suggesting possible latent syphilis. Appropriate antibiotic therapy was started. Due to lack of clinical improvement, broad-spectrum antibiotics, antituberculous therapy, and antifungal agents were subsequently administered. Antiretroviral therapy could not be initiated immediately since opportunistic infections had not been excluded. As radiological and clinical improvement was absent and definitive diagnosis was needed, a transsphenoidal pituitary biopsy was performed. Histopathology revealed high-grade lymphoid infiltration consistent with diffuse large B-cell lymphoma. Unfortunately, the patient developed pneumonia and septic shock in the early post-biopsy period and died in the ICU. Conclusion Although rare, HIV infection should be considered in rapidly progressive infiltrative pituitary lesions. In HIV-positive patients, differential diagnosis of pituitary involvement is crucial, as treatment strategies differ significantly. Radiology alone is insufficient for diagnosis, and invasive procedures should not be delayed when indicated. In immunosuppressed individuals, the decision and timing of transsphenoidal biopsy are critical due to infectious complications, necessitating a multidisciplinary approach.Figure 1:Pituitary MRI showing a sellar mass extending into the stalk and invading the left cavernous sinus Table 1:Anterior Pituitary Hormone Levels
Eralp et al. (Thu,) studied this question.