A negative p16 does not rule out HPV-associated cervical carcinoma

The edition in brief

In a single-institution series of 201 cervical squamous cell carcinomas, 11 (5.5%) showed negative or focal p16: four with high-risk HPV, six HPV-independent and one with low-risk HPV. Three of the four high-risk HPV cases with complete p16 loss also lost MTAP, suggesting p16/MTAP co-deletion, and this was seen in precursor lesions too. The authors recommend pairing p16 with HPV testing or prior HPV results. The Italian PROMETHEUS study ran comprehensive genomic profiling with an HRD assay on 295 high-grade serous carcinomas, with 96.6% technical success, BRCA1 or BRCA2 variants in 23%, a genomic instability score of 42 or more in 46.7%, and germline variants in 32 of 46 patients referred for counselling. A Histopathology series of 58 borderline or malignant phyllodes tumours found stromal mitoses of 30 or more per 10 HPF and malignant heterologous elements independently linked to metastasis; the Tan system matched WHO 2019 in 97%, while the Refined Criteria upgraded half of borderline tumours without better prediction. A four-case series describes a vulvovaginal epithelioid mesenchymal neoplasm with deciduoid morphology, two with germline BAP1 variants. The pearl covers sampling phyllodes tumours.