8220 Panhypopituitarism due to Granulomatosis with Polyangiitis - Wegener's Granulomatosis. A Very Rare Cause of Panhypopiturism: A Case Report

Abstract Disclosure: T.D. Bertolacini da Silva: None. V.S. da Silva: None. P.R. Fiorin: None. J.S. Freire: None. C.G. Braga: None. M. Canzian: None. C. Machado: None. Background: Granulomatosis with Polyangiitis (GPA) is a necrotizing granulomatous vasculitis and pituitary involvement is less than 1%. We report a case of pituitary involvement, with CDI, and later panhypopituitarism. Clinical Case: A 43-year-old man was admitted in a hospital due to a headache 3 months ago. CT showed an expansive lesion in posterior fossa and hydrocephaly. Submetted for withdrawal of a Schwannoma and peritoneal shunt, with ipsilateral peripheral facial paralysis. After 1 year, started with polyuria and polydipsia, CDI was diagnosed and DDAVP started. Pituitary MRI showed a small rounded image in the sella turcica, cystic, 0.8 x 0.5 x 0.8cm. After 6 months, readmitted on hospital after trauma in surgical scar, with abscess, accomplished debridement and started oxacillin, with good controls of electrolytes and diuresis: Na 144 mmol/L (137-145 mmol/L). Readmitted after 2 months for surgical wound infection, on that occasion hyponatremia was diagnosed. Other tests were requested: TSH < 0.0015 uIU/mL (0.49-5.58 uIU/mL/mL), free T4 0.68 ng/dL (0.89-1.53 ng/dL), repeated TSH 0.036 uIU/mL and free T4 0.63 ng/dL, central hypothyroidism has been confirmed and levothyroxine started. Pituitary MRI was repeated with enlarged adeno-pituitary: 1.9 x 1.7 x 1.1cm, extension to the suprasellar cistern, compression, and superior displacement of the optic chiasm. Other tests: GH 0.173 ng/mL (< 3 ng/mL), IGF1 66 ng/mL (58-219 ng/mL), testosterone < 7.30 ng/dL (12-59 ng/dL), LH 0.1 mIU/mL (1.9-12.5 mIU/mL), prolactin 0.66 ng/mL (2.1-17.7 ng/mL), ACTH 6.66 pg/mL (< 46.0 pg/mL), confirmed pan-hypopituitarism. After 1-month patient started with petechiae and persisted with hyponatremia, SIADH hypothesis made. Chest CT showed a solid pulmonary nodule, spiculated, 2.6 x 2.1 x 1.8cm, first biopsy was inconclusive. After repeating the chest CT there was persistence the pulmonary nodule 4.2 x 5.8 x 4.4cm. Videothoracoscopy was perfomed and anatomopathological confimed GPA and C-ANCA positive. The patient received prednisone, ivermectin, pulse therapy (methylprednisolone) and cyclophosphamide. After 8 months admitted on hospital due to pneumonia and exogenous Cushing's syndrome, new tests were requested: pituitary MRI showed a hypocontrasting and heterogeneous on the sellar cavity 0.4 x 0.7 x 1.0cm, showing reduction of the lesion after treatment of the rheumatological disease. Patient also received treatment with Rituximab and the last pituitary MRI: hypocontrasting lesion, sometimes with a cystic appearance in the sellar cavity. Currently, in use: testosterone replacement, desmopressin prednisone, levothyroxine, rosuvastatin/ezetimib, cholecalciferol, colchicin and ibandronate sodium. He presented with an improved quality of life. Conclusion: GPA should be considered in cases of CDI and hypopituitarism when sellar disorders were discarded, and if a vasculitis is suspected. Presentation: 6/1/2024