History: A 50-year-old lady presented in March-08 with clinical features consistent with Cushings syndrome and was diagnosed with pituitary driven ACTH-dependent Cushings disease on the basis of the following investigations; elevated 24 hours urinary free cortisol 1660 nmol/l; baseline cortisol 1230 nmol/l; serum cortisol levels post low dose and subsequent high dose dexamethasone suppression tests 722 nmol/l and 1032 nmol/l respectively; serum cortisol post 100 mcg CRH 979 nmol/l; basal ACTH 36 pmol/L in the context of cortisol 800 nmol/l; ACTH precursor conc. 271 pmol/L(NR <100). Her MRI pituitary showed a homogenous mass extending into the sphenoid sinus and posterior aspect of the clivus measuring 1.8×1.2 cm with no direct involvement of the pituitary fossa. Petrosal sinus sampling results are shown below. Management Metyrapone dose was titrated up to 4000 mg/d in preparation for transphenoidal hypophysectomy in September-08 (uncomplicated but with evidence of bony invasion and postoperative cortisol 94 nmol/l). Histolology was consistent with an anterior pituitary adenoma with positive immunohistochemistry for ACTH but a high mitotic rate and atypia with potential for aggressive behaviour. High dose (54 Gy) pituitary radiotherapy was administered (April-09). Residual ACTH-driven cortisol excess necessitated reintroduction of metyrapone (4000 mg/d) (June-10) and laparoscopic bilateral adrenalectomy (April-11). 1-month post adrenalectomy she developed weightloss, anorexia, worsening pigmentation, neck and popliteal lymphadenopathy and widespread induration of her skin. Lymph node FNA & biopsy and skin biopsies show histology consistent with original pituitary histology. FDG-PET scan confirmed metabolically active 4 cm right-cervical node and numerous areas of high metabolic activity in the skin. Octreotide scan showed uptake in the right cervical adenopathy. Systemic chemotherapy with Carboplatin and Etoposide has commenced.
Conclusions: Cushings disease associated with pituitary carcinoma is a rare. Metastatic pituitary carcinoma presents significant challenges in its management.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.
Pituitary Sinus Sampling Results Unable to cannulate left petrosal sinus