Endocrine Abstracts

Over the last decade 824 pituitary tumours have been removed in our centre. Of these, 114 (13.8%) were corticotroph adenomas. We present four unusual cases of corticotroph adenoma showing transition from Cushing’s disease to a hormonally inactive adenoma (case 1 and 2) or vice versa (case 3 and 4).

Case 1: A 51-year-old man was admitted with a 2-year history of weight gain, arterial hypertension and chiasmatic syndrome. Cushing’s disease (CD) due to an aggressive pituitary macroadenoma (stage 2C) was diagnosed. The tumour was partially removed by transphenoidal (TSF) approach. Six months later a second operation was carried out to remove the residual tumour and the patient developed panhypopituitarism requiring hormonal replacement therapy, which included cortisone acetate. Three years later a recurrence of the tumour in the subfrontal region was depicted by MRI without clinical or biochemical evidence of CD. A third operation was performed, but craniotomy was\necessary. Immunohistochemistry (IHC) studies of the specimens from the first, second, and third surgery were similar and showed diffuse immunoreactivity for ACTH.

Case 2: A 40-year-old woman was admitted because of a recurrence of a large pituitary adenoma (stage 2D). Five years before admission she had been operated by TSF approach because of CD. On admission, there were no signs or symptoms of hypercortisolism and biochemical analysis excluded CD. She underwent surgery by TSF approach; 3 years later, she was operated by craniotomy. IHC studies showed diffuse immunoreactivity for ACTH in all the specimens obtained from first, second, and third surgery. According to WHO classification, a diagnosis of atypical adenoma was made in the specimen obtained from the last operation.

Case 3: A 49-year-old man with a 2-year-history of nonfunctioning pituitary adenoma (NFA) was admitted because of clinical suspicion of CD, which was confirmed by biochemical tests. Of note, 1 year before admission a low-dose desametazone suppression test had been excluded CD. IHC studies of the specimens from surgery confirmed immunoreactivity for ACTH.

Case 4: A 47-year-old woman was operated because of aNFA (14 mm). IHC studies revealed diffuse immunoreactivity for ACTH. Throughout the follow up, the developed CD (3 years later).