A rare case of pituicytoma presenting with severe Cushing disease A case report and review of literature

Rationale: Pituicytomas are exceptional rare tumors in the sellar and suprasellar regions with clinical manifestations, such as headache, visual disturbance, hypopituitarism, and decreased libido. Unlike that of common pituitary adenoma, the association between pituicytoma and Cushing disease (CD) is extremely rare. There were only 6 reported cases till now. In the current study, we describe an unusual case of pituicytoma associated with severe CD with a recurrence-free follow-up period of 49 months. Patient concerns: A 32-year-old woman was referred to our hospital with moon face, central obesity, and purple stripes on the lower limbs. Diagnoses: The plasma cortisol level was 1122 nmol/L. The low-dose dexamethasone suppression test failed to suppress plasma cortisol. This test provided evidence of nonpituitary-dependent CD. However, magnetic resonance imaging demonstrated a sellar mass measuring approximately 7.6 x 5.7 mm. The patient was diagnosed with pituitary microadenoma. Histopathological analysis of the tissue sections based on the findings from the immunohistochemical staining diagnosed it as pituicytoma. Interventions: Transsphenoidal surgery was performed to remove the pituitary mass. Outcomes: Within 2 months postoperatively, the patient's blood pressure and cortisol level decreased gradually and normalized on the 6th month when other symptoms of CD also disappeared. The patient is presently free from recurrence 49 months after the initial diagnosis. Lessons: Based on the postoperative remission, CD was caused by pituitary disorders. A reasonable assumption is that an extremely small coexisting adenoma was not detected by the surgeon and washed out during the dissection. Another possible explanation might be the mass effect caused by this intrasellar lesion.