A case of pituitary neuroendocrine carcinoma defying survival timeline.
Giri Somdatta S, Rashmi K G KG, Gopalakrishnan M S MS, Kamalanathan Sadish Kumar SK et al.
Metastatic pituitary neuroendocrine tumours (PitNETs) are exceedingly rare, accounting for less than 0.2% of all pituitary tumours; they typically have a poor prognosis, with patient survival limited to 2-4 years because of aggressive local invasion and metastatic spread. We describe a unique case of a 50-year-old man with an adrenocorticotropic hormone (ACTH)-secreting pituitary macroadenoma initially resected in 2007 who subsequently developed multiple recurrences and ultimately developed a metastatic PitNET. The patient underwent repeated surgical resections, stereotactic radiosurgery, radiotherapy, and systemic therapies, including temozolomide (TMZ), peptide receptor radionuclide therapy (PRRT), and somatostatin analogues. Histopathology evolved from a low-grade to high-grade PitNET with a Ki-67 index of up to 50%, although p53 remained negative, possibly contributing to his unusually prolonged survival. Notably, methylation of the O-6-methylguanine-DNA methyltransferase (MGMT) promoter likely enhanced the patient's favourable response to TMZ. Despite multiple intracranial and extracranial metastases, including involvement of the temporal lobe, parotid gland, and scapular bone, the patient survived for 17 years from the initial diagnosis and for 9 years from a confirmed metastatic disease, defying the typical prognosis. This case highlights the importance of vigilant long-term surveillance; the recognition of prognostic markers, such as Ki-67, p53, and MGMT status; and the role of multimodal therapy, including surgery, radiotherapy, and TMZ, in extending survival in patients with aggressive pituitary tumours. Although metastatic PitNETs generally portend a dismal outcome, individualised and sequential treatment strategies can occasionally result in exceptional long-term survival.