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Granulomatous and lymphocytic hypophysitis – are they immunologically distinct?
Author(s) -
Rao Shilpa,
Mahadevan Anita,
Maiti Tanmoy,
Ranjan Manish,
Shwetha Shivayogi Durgad,
Arivazhagan Arimappamagan,
Saini Jitender
Publication year - 2016
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/apm.12603
Subject(s) - hypophysitis , pathology , histiocyte , medicine , giant cell , immunology , pituitary gland , hormone
Hypophysitis includes three histopathologically distinct entities – granulomatous, lymphocytic and xanthomatous forms. Etiopathogenesis and the immunological differences among these is not well characterized. This study aims to explore the immunopathogenesis of granulomatous and lymphocytic forms of hypophysitis. Demographic, clinical, endocrine function and radiological features of 33 histologically confirmed cases of hypophysitis were reviewed. Immunophenotyping of inflammatory component was performed in 13/33 cases. Visual disturbances (46%), headache (36%), polyuria/polydipsia (6%), menstrual disturbance (6%) and galactorrhoea (6%) were the frequent presenting symptoms. Endocrine abnormalities were noted in 11/18 cases evaluated (61%). Hypothyroidism was the most common endocrine abnormality (33.33%) followed by hyperprolactinaemia (22%) and hypocortisolism (16.66%). On neuroimaging, sellar mass with variable contrast enhancement was observed. On histology, granulomatous hypophysitis ( GH ) was more common (84.84%) than lymphocytic hypophysitis ( LH ) (15.15%). In GH , the infiltrate had almost equal proportions of CD 3+ T cells and CD 68+ histiocytes. Cytotoxic T cells ( CD 8+) predominated [ CD 4: CD 8 < 1]. CD 20+ B cell component ranged from <5% to 50%. Fibrosis, necrosis and giant cells accompanied GH . LH in contrast, had CD 4+ T‐helper cell predominance [CD4: CD8 > 1]. CD 68+ histiocytes constituted <20% and CD 20+ B cells, 5–40% of the infiltrates. In conclusion, GH revealed cytotoxic T cell and histiocyte rich infiltrate in contrast to CD 4+ T‐cell predominance in LH suggesting that the two forms have distinct immunological mechanisms in evolution, an autoimmune process in LH and type IV hypersensitivity response in GH .