Poster Presentation The Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2014

Acromegaly in a patient with Primary Polycythaemia: A case report (#267)

Rakesh Mallikarjunan 1 , Sally Newsome 1
  1. Canberra Hospital, Phillip, ACT, Australia

A 66-year-old man with recent diagnosis of Primary Polycythaemia was referred for management of Pituitary macroadenoma, identified on a pituitary MRI performed for frequent dizzy spells. It showed a 2.4cm sellar mass compressing and elevating the optic chiasm. On further questioning, he reported increase in ring and shoe size, arthritis affecting his hands, elbows and knees and symptoms of obstructive sleep apnoea. Physical examination findings consistent with acromegaly such as spade like hands, wide feet, increased interdental separation were present. There was bilateral gynaecomastia. His blood pressure was 150/95 mm of Hg. A formal visual field assessment showed early bitemporal hemianopia. Further investigations revealed an elevated IGF 1 level of 53nmol/L (8-42), but GH didn’t fall below 1 ng/ml during an oral Glucose tolerant test. Prolactin level was mildly elevated at 1030mIu/L and testosterone was low normal at 10nmol/L. Rest of the pituitary profile was normal.

He was diagnosed with GH secreting pituitary tumour and underwent transphenoidal resection of the pituitary tumour. Unfortunately, his postoperative period was complicated by epistaxis and respiratory arrest requiring mechanical ventilation. Post operatively, polycythaemia resolved, GH levels became undetectable, IGF 1 levels normalised. Pituitary MRI didn’t show a residual tumour. His recovery was complicated with panhypopituitarism.

Discordant IGF 1 and GH values have been reported in acromegaly. Importance of this phenomenon is uncertain, but it can pose significant dilemmas during management. Secondary polycythaemia can occur in acromegaly due to excessive chronic stimulation of JAK2/STAT pathway leading to proliferation of myeloid progenitor cells but co-occurrence of acromegaly and primary polycythaemia is an extremely rare event, with only one case report published to date. Another report suggested increased prevalence of myeloproliferative neoplasms in acromegalic patients. The role of JAK2 mutation in development of acromegaly remains to be determined in these patients.