Intracranial seeding of pituitary neuroendocrine tumor: a case report.

Background: Pituitary neuroendocrine tumors (PitNETs) are predominantly benign, though a minority may exhibit invasive tendencies. A diagnosis of metastatic PitNETs, in the absence of malignant histology, hinges on the identification of craniospinal and/or systemic metastases. Only a minority of PitNETs exhibit intracranial seeding. Notably, craniotomy for PitNETs excision is a prominent catalyst for iatrogenic seeding. Case Description: This article presented a compelling case that 15 years following craniotomy for the resection of a somatotroph PitNET, a lesion emerged at the left frontal base within the ethmoid sinus. Subsequent post-operative pathology unveiled a mature plurihormonal pituitary specific transcription factor 1 (PIT-1)-lineage PitNET. Growth hormone (GH) levels decreased significantly from 22.8 ng/mL pre-operation to 2 ng/mL post-operative, and concurrently, prolactin (PRL) levels decreased from 26.7 ng/mL pre-operation to 4.5 ng/mL post-operation. Furthermore, in the follow-up examination conducted 5 months after the operation, both GH and PRL levels were found to be within the normal range for the patient. This robustly suggested that the initial surgical procedure played a key role in the development of the lesion. Conclusions: This underscores the paramount significance of strictly adhering to the non-tumor removal during craniotomy for PitNETs excision. Regardless of apparent complete resection on imaging, it remains imperative to conduct routine follow-up evaluations, encompassing both imaging studies and hormone level assessments.