Images In...: Giant somatotropinoma

A 28-year-old man presented with fatigue and pronounced weakness. He had a history of headache, coarsening of facial features and progressive decline in vision for the previous 4 years. He also complained of cold intolerance, decreased libido, arthralgia in both knees, and proximal muscle weakness for the last 6 months. On examination, he had features suggestive of active acromegaly. On investigation, he was found to be hypothyroid (thyroxine (T4) 50 nmol/l, normal range (NR) 62–163 nmol/l; thyroid stimulating hormone (TSH) 0.2 uU/ml, NR 0.27–4.2 uU/ml), hypocortisolic (serum cortisol 12.8 nmol/l, NR, 171–536 nmol/l), and hypogonadal (serum testosterone 0.88 nmol/l, NR 9–27 nmol/l). His serum basal growth hormone (GH) was 142 ng/ml (normal <0.4 ng/ml), and it was non-suppressible after glucose load (155 ng/ml, normal <1 ng/ml). Serum IGF-1 concentration was 792 ng/ml (NR 117–329 ng/ml), and serum prolactin was 38.4 ng/ml (NR 5–20 ng/ml). Brain magnetic resonance imaging (MRI) showed sellar mass with huge lobulated suprasellar component (70×62×60 mm) with cystic changes and frontal lobe extension (fig 1). The patient underwent transsphenoidal followed by transfrontal subtotal excision of the tumour. Histopathology of the tumour showed pituitary adenoma with positive immunostaining for growth hormone. Currently, the patient is on hydrocortisone, L-thyroxine, and testosterone replacement, and treatment with radiotherapy is planned. Figure 1 Coronal (A) and sagittal (B) post-contrast magnetic resonance image T1 weighted sections showing a large intrasellar tumour with suprasellar component. Suprasellar solid component shows a lobulated margin with peripheral non-enhancing cystic areas (margins ...