PMON100 IgG4 hypophysitis with granulomatous histopathology

Abstract

Abstract Background IgG4-related disease is characterized by a dense lymphoplasmacytic infiltrate rich in IgG4 plasma cells that may be accompanied by elevated serum IgG4 levels, presence of granulomatous histopathology with multinucleated giant cells has not been reported in patients with IgG4 related hypophysitis.Clinical case: A 39-year-old female with no significant past medical history until April of 2021, when she developed gradual onset of headaches. MRI brain showed a mass in the sella, she was treated for over a month with glucocorticoids by ENT and her headaches improved. She finished the course of glucocorticoids, and soon after, she had a recurrence of her symptoms. Repeat brain MRI revealed a large pituitary mass and she had her first endoscopic endonasal transsphenoidal resection on 8/2021 at an outside hospital. Pathology report of the surgery suggested that she had a colloid cyst of the pituitary and cultures grew actinomyces and streptococcus oralis, likely, as a consequence of contamination from an ethmoid sinus infection/surgical infection, she was treated with antibiotics. Surgery was also complicated by diabetes insipidus for which she is taking desmopressin tablets.She presented to our hospital in November 2021, with persistent symptoms (headaches and worsening vision), and a postoperative brain MRI showing an expansion of the lesion with compression of the optic chiasm, she was evaluated by neurosurgery who recommended repeat revision endoscopic endonasal transsphenoidal resection of this lesion.The patient underwent a second transsphenoidal surgery on 11/29/2021 at our institution. During admission TSH was 0.123 mcIU/ml (0.27-4.2mcIU/ml) with Free T4 0.52ng/dL (0.93-1.7ng/dL). She was discharged on hydrocortisone, desmopressin tablets, and levothyroxine.The pathology report of the second surgery revealed mixed chronic and acute inflammation with granulomatous components containing histiocytic clusters and multinucleated giant cells. Many plasma cells, rare eosinophils, and foci of neutrophils are present. The ratio of IgG4 to IgG is over 70%, with more than 10 IgG4 (+) cells per 10HPF. GMS and AFB were negative for fungi and mycobacteria.Patient's outpatient labs were consistent with panhypopituitarism with AM cortisol of 1.9mcg/dL, ACTH 19pg/mL (6-50 pg/ml), FSH 6.5 mIU/ml, LH 2.4 mIU/ml and estradiol <15pg/ml. TSH was 1.26 mcIU/ml (0.27-4.2mcIU/ml) with Free T4 0.8ng/dL (0.8-1.8ng/dL). IGF-1 level was 72ng/ml (79-259ng/ml). Prolactin was 7.0 ng/ml (3.0-30.0ng/ml). IgG4 serum level was 100.2mg/dL (4.0-86.0mg/dL), IgG1 serum level was 446mg/dL (382-929mg/dL). Conclusion This is a unique patient with panhypopituitarism that meets the criteria for IgG4 related hypophysitis but also has secondary granulomatous components developed after the rupture of the colloid cyst during the first surgery. The implications of these findings are unknown in terms of management and prognosis. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.