Endocrine Abstracts

Background

Pituitary carcinoma (PC) is a very rare clinical entity, which is defined as a pituitary tumor that has metastasized to sites distant from the pituitary. It may present as hormone-secreting, invasive and recurrent macroadenoma causing a mass effect.

Case presentation

We present a 58-years old male patient with corticotroph pituitary carcinoma and brain metastases who underwent 9 neurosurgical interventions, radiotherapy and chemotherapy with temozolomide. In 1995 a non-functioning pituitary macroadenoma impinging the optic chiasm and causing visual filed defects was visualized on MRI. First debulking transcranial surgery was performed in 1995 and led to improvement in visual field but was complicated by anterior pituitary deficiency and diabetes insipidus. In 2006 a significant regrowth of a tumour was noted. The patient was again operated in 2006 and then due to aggressive tumor growth he required further debulking surgeries in 2007, 2008, 2009, 2010 and 2011. In 2012 ACTH-dependent Cushing syndrome was diagnosed and the patient was administered ketoconazole but long-term therapy was impossible because of the toxic liver injury. In 2013 stereotactic fractionated radiotherapy (5400 cGy/g) was applied and allowed for tumour size reduction and remission of hypercortisolemia. Despite clinical improvement, in 2014 routine pituitary MRI showed 3 brain metastases. Further imaging studies, i.e. 18-FDG PET/CT and somatostatin receptor scintigraphy were performed revealing increased radiotracer uptake only by a residual pituitary tumor mass. Transcranial biopsy from a lesion in the parietal lobe confirmed metastasis of corticotroph pituitary carcinoma. Pathology report from the next transcranial pituitary surgery in 2015 confirmed a highly proliferative Crooke cell corticotroph adenoma (ACTH (+) p53 >30%, Ki-67>5%, MGMT<5%). Subsequently, radiosurgery (gamma-knife) of 3 metastatic lesions was applied and temozolomide in a dose of 400mg/day for 5 days, 14 cycles in total, was initiated achieving stabilization of the disease. In 2017 MRI showed progression of the tumor requiring next transsphenoidal surgery and new brain metastases. Gamma-knife radiotherapy was performed again in 2019 to brain metastases and consecutive pituitary neurosurgery in 2020. Due to deteriorating symptoms of hypercortisolemia and positive response to short-acting pasireotide test, pasireotide LAR has been initiated in 2020.

Conclusions

The management of PC is challenging, requiring a multimodal approach using repeated neurosurgeries, radiotherapy and chemotherapy. Despite the usually described in the literature poor prognosis in PC, this multimodal management may lead to long-term survival, even 7 years as in presented case.