Malignancy arising in adamantinomatous craniopharyngioma: Report of a rare case with unusual morphologic features.

Adamantinomatous craniopharyngioma is a grade 1 tumor that arises in a sellar/suprasellar location. Despite being a grade 1 tumor, there is high recurrence and endocrinal insufficiency. Malignancy arising in craniopharyngioma is extremely rare, has a dismal prognosis, and is currently not included as a separate entity in the World Health Organization Classification of Central Nervous System 5th edition. Here we describe a case of adamantinomatous craniopharyngioma and its malignant counterpart. The malignant part had unique histomorphology and basaloid cells with pseudoglandular architecture and a myxoid background. It bore a striking resemblance to adenoid cystic carcinoma. Both the benign and malignant counterparts were beta-catenin and SOX-2 positive, providing proof of the malignant part arising from the benign part. Tumors like squamous cell carcinoma and odontogenic ghost cell carcinoma have been described in cranipharyngioma. This case study is the first to describe this unique morphology of adenoid cystic carcinoma-like features. The possibility of adenoid cystic carcinoma was excluded by immunohistochemistry.

Evaluation of prognostic biomarkers in meningiomas and their clinical implications in settings with limited resources.

Background: The 5th edition of the World Health Organization (WHO) Central Nervous System (CNS) tumor classification for meningiomas acknowledges the clinical relevance of genomic profiling studies and emphasizes the importance of incorporating molecular information alongside histopathological features, leading to more accurate diagnoses and improved patient care. Methods: We analyzed 206 meningioma samples (108 histological grade 1, 89 grade 2, and 9 grade 3) to study pTERT mutations, CDKN2A/B homozygous deletion, loss of H3K27me3, and p16 expression. The association of these molecular markers with survival outcomes was also assessed. Results: pTERT mutation was found in 4.85% of cases, predominantly occurring in histological grade 2 (11.24%), while none of the histological grade 1 or 3 meningiomas exhibited this mutation. CDKN2A/B gene deletion was absent in grade 1 and detected in 2.24% of grade2, and 33.3% of histological grade 3 cases. There was a significant increase in loss of H3K27me3 with higher tumor grades, while p16 loss was observed in over 50% of cases across all histological grades. The presence of pTERT mutation and CDKN2A/B homozygous deletion resulted in the reclassification of 5.33% (11/206) of meningiomas as integrated grade 3. pTERT mutation and CDKN2A/B deletion, emerged as prognostically relevant markers, showing significant differences in progression-free survival (PFS) between integrated grade 3 and histological grade 2 meningiomas (P = .0002). Conclusions: pTERT mutations are the most clinically relevant genetic alterations in meningiomas. Routine testing for pTERT mutations can identify high-risk cases of histologically grade 2 meningiomas, providing crucial prognostic information for treatment planning. CDKN2A/B alteration is rare and not cost-effective in assessing meningiomas. Immunohistochemical assessment of p16 and H3K27me3 expression lacks significant prognostic value. Assessment of pTERT mutations offers a cost-effective and valuable diagnostic tool for meningiomas.

Novel EGFR mutations in diffuse midline gliomas using cost-effective strategies: A report of 2 cases.

Background: Diffuse midline gliomas (DMGs) are malignant tumors predominantly affecting children, often leading to poor outcomes. The 2021 World Health Organization classification identifies 3 subtypes of DMGs, all characterized by the loss of H3K27 trimethylation. Here, we report 2 cases of DMG with Epidermal Growth Factor Receptor (EGFR) mutations within exon 20, contributing to the understanding of the molecular complexity of these pediatric brain tumors. Methods: An economical immunohistochemical panel was designed to aid in the diagnosis of most DMGs in resource-constrained regions. Sanger sequencing was employed to identify rare EGFR mutations in exon 20 of 2 cases. Results: Molecular analyses of 2 cases of DMG revealed novel EGFR mutations within exon 20. These mutations were identified using cost-effective diagnostic approaches. The presence of EGFR mutations expands the molecular landscape of DMGs and highlights the genetic heterogeneity within this tumor entity. Conclusions: These findings underscore the molecular heterogeneity of DMGs and the significance of identifying novel mutations, such as EGFR mutations in exon 20. Further research into the molecular mechanisms underlying DMGs is warranted to advance therapeutic strategies and improve outcomes for pediatric patients.