Double PitNETs: A Case Report and Literature Review.

Double pituitary neuroendocrine tumors (double PitNETs) are two distinct tumors in the same gland and are infrequent in clinical practice. In typical double PitNETs, an MRI detects two separate tumors that are diagnosed by pathology; they could also appear as a single tumor, and pathology would then identify the two independent tumors. A literature review was conducted, and 142 cases were analyzed to determine the characteristics of double PitNETs. Of these cases, acromegaly (45.5%) was the most common clinical feature, followed by Cushing's disease (35.1%) and prolactinoma (17.9%), indicating that double PitNETs are usually noticed by hormonal excess symptoms due to at least one functional tumor. The pathological analysis of 284 tumors showed that somatotroph (28.9%) and corticotroph (26.8%) tumors were predominant, with a recent increase in the proportion of gonadotroph tumors. Regarding transcription factors, 51.1% were of GH-PRL-TSH PIT1-lineage, 26.1% ACTH TPIT-lineage, and 17.9% LH-FSH SF1-lineage. The radiological analysis of 82 cases revealed that double tumors (45.1%) and single tumors (47.6%) were comparable, suggesting that double PitNETs are often detected as a single tumor, and attention should be paid to hidden micro-tumors during surgery. Double PitNETs are complicated by a wide variety of clinical, radiological, and pathological findings, but diagnostic and therapeutic approaches are advancing.