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Granulomatous Hypophysitis Masquerading As Pitutary Macroadenoma

Author Information

Deshmukh P*, Shende D**, Kalappa S***, Chauhan AR****
(* 3rd year resident, **Assistant Professor, ***2nd year resident , ****Professor, department of Obstetrics and Gynecology, Seth G. S. Medical College and KEM Hospital, Mumbai, India.)

Abstract

Diagnosis of pituitary disorders are challenging during pregnancy due to physiological and clinical changes. Granulomatous hypophysitis (GH) is a rare inflammation of hypophysis including pituitary gland and infundibulum area. Diagnosis and treatment of GH in pregnancy is difficult as its clinical presentation and imaging are similar to pituitary adenoma. We present a 30 year old G4P2L1SA1 who was operated for pituitary macroadenoma at 24 weeks of gestation; histopathology examination was suggestive of granulomatous hypophysitis. She delivered a healthy baby by emergency LSCS for meconium stained amniotic fluid.

Introduction

Hypophysitis is rare with an incidence of one per 9 million per year.[1] On histopathology examination hypophysitis is classified as lymphocytic hypophysitis (LH) which is most common in pregnancy, granulomatous hypophysitis (GH), xanthomatous, necrotizing, IgG4 related, lymphogranulomatous and xanthogranulomatous hypophysitis. LH is characterized by infundibulo-neurohypophysitis by autoimmune lymphocytic infiltration. GH is the second most frequent type, seen in endemic areas. It is characterized by multinucleated giant cells, histiocytes, granuloma and fibrosis. 
Causes of GH are tuberculosis, sarcoidosis, syphilis, pituitary adenoma, Langerhan’s histiocytosis, Wegener’s granulomatosis and Rathke’s cleft cyst rupture.[2] Clinical symptoms are headache, visual disturbances, nausea, vomiting and diabetes insipidus (DI). Diagnosis is based on MRI imaging which shows characteristic of thickened pituitary stalk.

Case Report

30 year old Gravida 4 Para 2 Living 1 Abortion 1 with 24 weeks of gestation was admitted in neurosurgery department of our tertiary center with complaints of hemicranial headache and diminished vision in right nasal field since one month, followed by diminished vision in the entire eye since 2 - 3 days and vomiting since 10 days. There were no cushingoid or acromegaloid features, no diplopia or ptosis, and no polyuria. On endocrine and biochemical evaluation, serum prolactin was elevated (61.83 ng/ ml), thyroid, renal and liver function tests were normal (TSH 3.36 uIU/ ml, free T4 1.02 ng/ dl) and serum cortisol was 26.23 µg/ dl (normal 10- 42 µg/ dl). On MRI evaluation done prior to admission, there was a 9.3 x 19 x 16 mm well- defined sellar and suprasellar lesion extending into the right cavernous sinus with encasement of right internal carotid artery, and superiorly indenting the optic chiasma, suggestive of pituitary macroadenoma. On repeat MRI four days later at our institute, the findings were the same; additionally there was thickening of the pituitary stalk suggestive of probable hypophysitis. Antenatal examination was unremarkable; uterus was 24 weeks in size, relaxed, and fetal heart rate was 146 beats per minute on Doppler. As patient was 24 weeks’ pregnant, medical management with high dose injection methyl prednisolone (1 gm thrice daily) was started. However, due to sudden deterioration of vision and no decrease in size of the adenoma, surgery was planned. She underwent sublabial rhino-septal transphenoidal excision of the sellar mass under general anesthesia at 26 weeks’ gestation. Fetal heart rate monitoring was done before and after the surgery. Post operatively patient had transient DI which was managed by injection desmopressin 2 microgram subcutaneous 12 hourly, matching input and output of fluid, for 2 days in conjunction with the endocrinologist. There were no other complications like CSF rhinorrhea. Post operatively, vision improved in the affected eye. She was started on tablet prednisolone 5 mg daily from day 2 of surgery, which was tapered to 2.5 mg daily and was continued for the duration of her pregnancy. Histopathology examination showed multinucleated giant cells and necrosis which was suggestive of granulomatous hypophysitis most likely tubercular; unfortunately as the probable diagnosis prior to surgery was macroadenoma, culture for acid fast bacilli was not done, and she was  started on anti tuberculosis medication Category I. She had regular antenatal and neurosurgery follow up. She presented in spontaneous labor at 40 weeks’ gestation and underwent emergency LSCS for fetal distress, under steroid cover (injection hydrocortisone 50 mg intravenously 8 hourly). She delivered a female child of 2.8 kg; postoperative period was uneventful. Basal cortisol level was 15.57 µg/dl on day 3 which was normal, hence tablet prednisolone was omitted, and she was discharged on day 5, on antituberculosis treatment.

Discussion

As GH is extremely rare, there is no data on incidence and prevalence during pregnancy. Major changes in hormone levels occur in pituitary macroadenoma. Hormone analysis in hypophysitis is important as it causes hypopituitarism, which was normal in our case. Prolactin and thyroid functions test act as markers in post operative state. Serum electrolytes and urine output should be monitored to diagnose diabetes insipidus during pre and post operative period. GH commonly occurs due to infectious diseases so laboratory tests and culture should be done to diagnose these, especially tuberculosis, when necessary. MRI scan of pituitary gland is characterized by enlargement of pituitary gland, thickened pituitary stalk that extends towards the hypothalamus and cavernous sinus, which helps in making proper diagnosis.[3] High dose of corticosteroid is considered in pregnant patient and in patients unsuitable for surgery. Corticosteroid is an effective treatment in cases of hypophysitis secondary to autoimmune disorders along with hormone replacement. DI is treated with desmopressin effectively. In case of side effects due to steroids, immune modulation with azathioprine is considered. Surgery is considered if the mass is increasing, visual disturbances do not improve, or increase, or recur. Low dose radiotherapy should be considered for resistant hypophysitis.[4]

Conclusion

Treatment of GH during pregnancy is challenging. Corticosteroids are considered as primary treatment along with desmopressin if patients have DI to avoid traumatic effects of surgery. Surgical treatment is useful for relieving the elevated pressure effects on optic and occulomotor nerve.

References
  1. Buxton N, Robertson I. Lymphocytic and granulocytic hypophysitis: a single centre experience. Br J Neurosurg. 2001 Jun;15(3): 242-5.
  2. Caturegli P, Newschaffer C, Olivi A, Pomper MG, Burger PC, Rose NR. Autoimmune hypophysitis. Endocr Rev. 2005 Aug; 26(5): 599-614. 
  3. Vasile M, Marsot-Dupuch K, Kujas M, Brunereau L, Bouchard P, Comoy J, et al. Idiopathic granulomatous hypophysitis: clinical and imaging features. Neuroradiology. 1997 Jan; 39(1):7-11.
  4. Selch MT, DeSalles AA, Kelly DF, Frighetto L, Vinters HV, Cabatan-Awang C, et al. Stereotactic radiotherapy for the treatment of lymphocytic hypophysitis. Report of two cases. J Neurosurg. 2003 Sep; 99(3): 591-6.
Citation

Deshmukh P, Shende D, Kalappa S, Chauhan AR. Granulomatous Hypophysitis Masquerading As Pitutary Macroadenoma. JPGO 2016. Volume 3 No. 8. Available from: http://www.jpgo.org/2016/08/granulomatous-hypophysitis-masquerading.html