Vulvar squamous cell carcinoma arising on human papillomavirus-independent precursors mimicking high-grade squamous intra-epithelial lesion: a distinct and highly recurrent subtype of vulvar cancer Aims: Each category of vulvar squamous cell carcinoma (VSCC), human papillomavirus (HPV)associated and HPV-independent, arises on a specific intra-epithelial precursor: high-grade squamous intraepithelial lesions (HSIL) and differentiated vulvar intra-epithelial neoplasia (dVIN), respectively. However, a subset of HPV-independent VSCC arises on an intra-epithelial precursor closely mimicking HSIL. We aimed to explore the clinicopathological features of the HPV-independent tumours with HSIL-like lesions and compare them with HPV-independent VSCC with dVIN and HPV-associated tumours with HSIL. Methods and results: We retrospectively identified 105 cases of surgically treated VSCC with adjacent intra-epithelial precursors. The cases were classified into three groups based on the HPV status and the adjacent precursor identified: (i) HPV-associated VSCC with HSIL (n = 26), (ii) HPV-independent VSCC with dVIN lesions (n = 54) and (iii) HPV-independent VSCC with HSIL-like lesions (n = 25). We analysed the histological and clinical features including the recurrencefree survival and disease-specific survival in the three groups. Patients with HPV-independent VSCC with HSIL-like lesions and with dVIN were older than patients with HPV-associated VSCC (76 and 77 versus 66 years, respectively, P < 0.001). HPV-independent VSCC with HSIL-like lesions recurred more frequently [hazard ratio (HR) = 3.87; P < 0.001] than HPVindependent VSCC with dVIN (HR = 2.27; P = 0.1) and HPV-associated VSCC (HR = 1). In the multivariate analysis, HPV-independent VSCC with HSIL-like lesions remained significant for recurrence. No differences in disease-specific survival were observed between the three groups. Conclusions: Even though VSCC with HSIL-like lesions are not associated with higher mortality, they are more likely to recur and might benefit from more intensive treatment strategies and closer surveillance after treatment.

INTRODUCTION: Molecular lymph node (LN) staging in early colorectal cancer (CRC) has demonstrated to be more precise than conventional histopathology pN staging. Tumor budding (TB) and poorly differentiated clusters (PDCs) are associated with LN metastases, recurrences, and lower survival in CRC. We evaluated the correlation between the total tumor load (TTL) in LNs from CRC surgical specimens with patient outcome, TB, and PDC. METHODS: In this retrospective multicentre study, 5,931 LNs from 342 stage I–III CRC were analyzed by both hematoxylin and eosin and molecular detection of tumor cytokeratin 19 mRNA by one-step nucleic acid amplification. TB and PDC were evaluated by hematoxylin and eosin and cytokeratin 19 immunohistochemistry. Results: One-step nucleic acid was positive in 38.3% patients (n = 131). Tumor Budding was low in 45% cases, intermediate in 25%, and high in 30%. Poorly Differentiated Clusters were low-grade G1 in 53%, G2 in 32%, and G3 in 15%. TB and PDC correlated with TTL, high-grade, lymphovascular and perineural invasion, pT, pN and stage ( P < 0.001). TB, PDC, and TTL ≥ 6,000 copies/µL were associated with worse overall survival ( P = 0.002, P = 0.013, and P = 0.046) and disease-free survival ( P < 0.001). Discussion: The implementation of more sensitive molecular methods to assess LN status is a promising alternative approach to pN staging, which could be integrated to other factors to help risk stratification and management of patients with early-stage CRC. This study demonstrates the correlation of the amount of LN tumor burden with TB and PDCs. TTL is related to the outcome and could be used as a new prognostic factor in CRC (see Visual Abstract, Supplementary Digital Content 2, http://links.lww.com/CTG/A512 ).

Most human papillomavirus (HPV)-independent penile squamous cell carcinomas (PSCCs) originate from an intraepithelial precursor called differentiated penile intraepithelial neoplasia, characterized by atypia limited to the basal layer with marked superficial maturation. Previous studies in vulvar cancer, which has a similar dual etiopathogenesis, have shown that about one fifth of HPV-independent precursors are morphologically indistinguishable from high-grade squamous intraepithelial lesions (HSILs), the precursor of HPV-asssociated carcinomas. However, such lesions have not been described in PSCC. From 2000 to 2021, 55 surgical specimens of PSCC were identified. In all cases, thorough morphologic evaluation, HPV DNA detection, and p16, p53, and Ki-67 immunohistochemical (IHC) staining was performed. HPV-independent status was assigned based on both negative results for p16 IHC and HPV DNA. Thirty-six of the 55 PSCC (65%) were HPV-independent. An intraepithelial precursor was identified in 26/36 cases (72%). Five of them (19%) had basaloid features, morphologically indistinguishable from HPV-associated HSIL. The median age of the 5 patients was 74 years (range: 67 to 83 y). All 5 cases were p16 and DNA HPV-negative. Immunohistochemically, 3 cases showed an abnormal p53 pattern, and 2 showed wild-type p53 staining. The associated invasive carcinoma was basaloid in 4 cases and the usual (keratinizing) type in 1. In conclusion, a small proportion of HPV-independent PSCC may arise on adjacent intraepithelial lesions morphologically identical to HPVassociated HSIL. This unusual histologic pattern has not been previously characterized in detail in PSCC. p16 IHC is a valuable tool to identify these lesions and differentiate them from HPVassociated HSIL.