Primary papillary epithelial tumor of the sella and posterior pituitary tumor show similar (epi)genetic features constitute a single neurooncological entity

BACKGROUND

"Primary papillary epithelial tumor of the sella (PPETS)" is a recently described rare tumor entity of the central nervous system (CNS) with stereotypic location in the sella. Comprehensive molecular investigations and epigenetic profiles of PPETS have not been performed to date.

METHODS

We report a comprehensive clinical, histopathologic and molecular assessment of 5 PPETS cases in comparison with a cohort composed of 7 choroid plexus papilloma (CPP), 7 central neurocytoma (CN), 15 posterior pituitary tumor (PPT) including 4 pituicytoma (PC), 6 granular cell tumors of the sellar region (GCT) and 5 spindle cell oncocytoma (SCO).

RESULTS

All PPETS had good outcomes. Immunohistochemically, PPETS tumors showed positive staining with TTF1, EMA, AE1/AE3, MAP2, and Vimentin, but were negatively stained with Syn, GFAP, CgA, and S100, and sporadically stained with Ki-67. In unsupervised hierarchical clustering and t-SNE analyses of DNA-methylation data, PPETS and PPT tumors formed a distinct cluster irrespective of their histologic types. However, PPETS tumors did not cluster together with CPP and CN samples. Similar findings were obtained when our samples were projected into the reference cohort of the brain tumor classifier. Substantial fractions of the PPETS and PPT tumors shared broadly similar chromosomal copy number alterations. No mutations were detected using targeted next-generation sequencing.

CONCLUSIONS

Though more cases are needed to further elucidate the molecular pathogenesis of these tumors, our findings indicate that PPETS and PPT tumors may constitute a single neurooncological entity.

Surgical histopathologic findings of 232 Chinese children cases with drug-resistant seizures

OBJECTIVES

The drug-resistant seizures are characterized by frequent and severe onset of seizures in childhood. There is only little literature had extensively explored the types of pathological brain damage in Chinese children cases. The present study aims to investigate the histopathologic findings and seizure outcomes of drug-resistant seizures in cases of 0-14-year-old children.

MATERIALS AND METHODS

About 232 children cases were retrospectively who underwent epilepsy surgery. The medical records, onset age, age of surgery, disease course, seizure type, pathological reports, and seizure outcomes of these patients were retrospectively analyzed.

RESULTS

The most common categories were malformations of cortical development (focal cortical dysplasia (FCD) was the most common type (94.36%, 67/71), found in 30.60% of the patients, tumors in 18.11%, glial scar in 12.50%, and encephalitis in 11.63%). It was found that the effective seizure outcome of FCD cases with shorter duration of epilepsy (<2 years, 87.23%) was better than that with longer duration (≥2 years, 60.00%) and the difference was statistically significant (χ²  = 4.76, p < .05). Patients with FCD I, FCD II, and tumor showed the relatively better postsurgical seizure outcome than patients with other pathological types.

CONCLUSION

The malformations of cortical development (MCD) (most FCD) were the most common pathological type for children cases in China with drug-resistant seizures. It was speculated further that the FCD patients with shorter duration of epilepsy before surgery seem to have a higher ratio of being seizure-free after surgery.