Transcriptional Subtypes on Immune Microenvironment and Predicting Postoperative Recurrence and Metastasis in Pheochromocytoma and Paraganglioma

Tumor tissues from 87 patients with pheochromocytoma and paraganglioma (PCPG) were collected from surgical resection specimens that had been archived as formalin-fixed paraffin-embedded (FFPE) blocks. All patients had complete clinicopathological information and follow-up records, including postoperative recurrence and distant metastasis status. For each case, one representative tumor block was selected by a pathologist, and total RNA was extracted from FFPE sections using a standard deparaffinization and RNA purification protocol. RNA libraries were prepared for bulk RNA sequencing using an FFPE-compatible workflow and sequenced on a BGISEQ platform to generate paired-end reads. This study aimed to define transcriptional subtypes of PCPG, to compare immune-microenvironment–related gene expression among subtypes, and to link expression patterns with clinical outcomes (recurrence/metastasis).