An invasive nasopharyngeal carcinoma with extension to the pituitary gland mimicking an invasive pituitary macroadenoma: A case report.

Herein, we report a rare case of invasive nasopharyngeal carcinoma with extension to the pituitary gland misdiagnosed as a pituitary macroadenoma. A 50-year-old woman was referred to our department with a diagnosis of pituitary macroadenoma. She presented with headache, visual disturbances, weakness, nausea, vomiting, and hypoglycemia. Polyuria was not reported. On pituitary magnetic resonance imaging, a large mass was observed to extend from the sella turcica to the sphenoid sinus, optic chiasm, and nasopharynx, leading to the initial diagnosis of an invasive pituitary macroadenoma. Biochemical investigations revealed corticotropin deficiency, secondary hypothyroidism, hypogonadotropic hypogonadism, and moderate hyperprolactinemia. Hormone replacement therapy was initiated. After hydrocortisone initiation, diabetes insipidus was revealed. Subsequent magnetic resonance imaging showed an infiltration of the nasopharynx with an extension to the pituitary gland. An endoscopic biopsy confirmed the diagnosis of undifferentiated nasopharyngeal carcinoma. The patient was referred to the oncology department for chemo and radiotherapy. Invasive nasopharyngeal carcinoma presenting with pituitary extension is very rare. It should be considered in the differential diagnosis of pituitary macroadenoma with hypopituitarism. Proper management of such cases requires a multidisciplinary approach.