How should patients with pituitary stalk lesions be evaluated?
A comprehensive history and physical examination should be performed, including medication review, travel history, evaluation for constitutional symptoms, and examination for possible extrapituitary manifestations of systemic disease. The following biochemical evaluation, as guided by clinical context, are also recommended:
1. Measurement of anterior pituitary hormones and the hormones they regulate, including: ACTH, cortisol, GH, insulin-like growth factor-1, TSH, free thyroxine, follicle-stimulating hormone, luteinizing hormone, testosterone (in men), estradiol (in women), and prolactin
2. Complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate, and C-reactive protein
3. Suspected sarcoidosis—serum calcium, angiotensin-converting enzyme (ACE), 1,25-dihydroxy vitamin D, +/− 24-hour urinary calcium excretion
4. Suspected germinoma—serum alpha fetoprotein and beta-human chorionic gonadotropin levels
5. Suspected granulomatosis with polyangiitis (formerly Wegener’s granulomatosis)—cytoplasmic antineutrophil cytoplasmic antibody (c-ANCA) and proteinase 3 ANCA.
6. Suspected TB—Quantiferon Gold in the presence of risk factors for TB (e.g., immunocompromised or infection with human immunodeficiency virus [HIV], travel to endemic areas)
7. Suspected IgG4-related disease—serum or CSF IgG4 levels.
8. Suspected Langerhans cell histiocytosis (LCH) disease (children)—radiographic skeletal survey, chest radiography, and positron emission tomography/computed tomography (PET/CT) scans to assess for extracranial granulomas which may be amenable to biopsy
9. Suspected CNS lymphoma (systemic or primary)—serum lactate dehydrogenase and HIV serology, CSF analysis (with flow cytometry)
10. Suspected infectious etiologies—lumbar puncture for CSF analyses, culture and sensitivity, +/− polymerase chain reaction (PCR)
Depending on the clinical context, initial biochemical evaluation, and MRI findings, additional imaging may include contrast-enhanced CT imaging of the neck, chest (+/− chest radiography), abdomen and pelvis are generally recommended to evaluate for possible systemic disease and to potentially identify sites for tissue biopsy. In addition, whole-body fluorodeoxyglucose positron emission tomography (FDG-PET) scans are recommended for presumed CNS lymphoma and LCH for staging and to monitor disease activity.