Endocrine Abstracts

Introduction: Hypophysitis is a rare pituitary inflammation due to primary and secondary causes. Xanthomatous hypophysitis is the rarest subtype and described with lipid-laden cystic areas, transparent cytoplasmic and lipid-laden histiocytes and foamy (xanthomatous) histiocytes. Although the etiology of xanthomatous hypophysitis is not clearly known, it has been suggested to develop as a result of autoimmune cause or inflammatory process of infiltration of cyst components from other sellar masses. Clinically, it shows symptoms similar to pituitary adenomas, but no case of hypophysitis accompanied by acromegaly has been reported among the few cases seen in the literature. We present a case with xanthomatous hypophysitis which was diagnosed after re-operation for acromegaly.

Clinical case: A 38-year-old female patient presented with complaints of headache, enlargement of the hands and feet, increase in shoe size, and enlargement of the jaw for 6 months. Physical examination revealed acromegaly, other systemic examination was unremarkable. Laboratory examination revealed IGF1:659 ng/ml (93.1–228) and GH:24.4:4.02 ng/ml (0.126–9.88) Other anterior pituitary hormones were within reference ranges. MRI revealed a 19×13 mm hypointense mass lesion in the right lateral half of the pituitary. Visual field evaluation was normal. The patient was operated with a prediagnosis of acromegaly. The pathology result was compatible with acromegaly. 3rd month follow-up revealed IGF1:554 ng/ml (93.1–228) GH:8.79, ng/ml (0.126–9.88) other anterior pituitary panel was again normal and imaging showed a 12×12 mm residual mass in the right half of the pituitary. After re-operation for the residual tumor the pathology specimen of the second operative pathology was reported as sparsely granular somatotroph adenoma favoring focal recurrence/residue in the adjacent area containing CD 68+ diffuse foci of xanthomatous hypophysitis. Medical treatment for acromegaly was started.

Conclusion: Although the pathogenesis of xanthomatous hypophysitis is unknown, it may develop as a local reaction to hemorrhage, degeneration necrosis and inflammation. Also, it has been previously associated with rathke cleft cysts (lit). However, to our knowledge reoperation for a somatotropinoma has not been defined as a secondary cause. Immunohistochemical staining is supportive to confirm the diagnosis in our case.