Endocrine Abstracts

Introduction: Atypical pituitary adenomas have higher risk of aggressive behaviour in particular by the higher growth, local invasion and high risk of recurrence after surgery. In acromegaly the resistance to somatostatin analogues may be another manifestation of these adenomas since higher levels of Ki-67 are associated with poor response to therapy.

Case report: A 41-year-old woman presented to our consult with history of headaches, growth of the hands, hyperhidrosis, carpel tunnel syndrome and enlargement of the lips with 3 years of evolution. She also mentioned complaints of neck pain and reported an episode of visual changes that reversed spontaneously. Hormonal evaluation revealed the following alterations: IGF1 1687 μg/dl (64–336), GT basal 25.6 ng/ml (<8) and a lack of GH suppression to <1 ng/ml on oral glucose tolerance test. Pituitary MRI revealed pituitary lesion with 24 mm craniocaudal diameter and 5 mm transverse diameter with invasion of the cavernous sinus. She was submitted to transsphenoidal resection. Tumour pathology showed diffuse expression of GH, prolactin multifocal expression and absence of expression of other pituitary hormones. Ki-67 labelling index was 8%. Sparse representation of p53.

Conclusion: Atypical pituitary adenoma. The MRI repeated 3 months after surgery showed persistence of tissue attributable to residual tumour invading the right cavernous sinus. The patient began treatment with somatostatin analogues. This is a case of acromegaly with several predictors of a possible failure of response to somatostatin analogues: young age, elevated levels of GH and IGF1 at diagnosis, macroadenoma with invasive growth and Ki-67 labelling index of 8%. In the presence of cases of atypical adenomas a multidisciplinary team of endocrinologists, neurosurgeons, pathologists and oncologists must work together in attentive and personalised follow-up of the patient in order to prevent disease progression.