Penile squamous cell carcinomas (SCC) originating in the shaft are rare. pT1/pT2 categories in the American Joint Committee on Cancer (AJCC) staging manual (8th edition) are poorly defined for SCCs arising in the dorsal shaft as anatomic structures differ between the glans and dorsal shaft (corpus spongiosum vs dartos/Buck's fascia, respectively). We reviewed six penile SCC cases exclusive to the shaft, an unusual presentation, identified amongst 120 patients treated with penectomy. We propose a novel pT staging system for dorsal shaft tumors tailored to its anatomic landmarks, where tumors extending to Buck's fascia are considered pT2 instead of pT1. The mean age at penectomy, average duration of follow-up, and mean depth of invasion were 64 years, 45 months, and 9.8 mm, respectively. Four cases were moderately differentiated, HPV-negative SCCs of the usual type and two cases were HPV-positive basaloid and warty-basaloid carcinomas. Three cases had nodal or distant metastasis at the time of penectomy, and histologic assessment in these cases showed invasion into the Buck's fascia or deeper. According to the current AJCC system, only one of these three cases would be staged as ≥pT2. In contrast, all three metastatic tumors would be staged as ≥pT2 in the proposed model. At last follow-up, one patient died of disease-related complications. Based on this limited series, the proposed staging model appears to suggest better patient stratification for pT1/pT2 stages. This model incorporates Buck's fascia, which has been postulated as a pathway of tumor infiltration. Additional studies are needed to validate this model.
Human pathology. 2022 Dec 22 [Epub ahead of print]
Burak Tekin, Ruifeng Guo, John C Cheville, Sofia Canete-Portillo, Diego F Sanchez, María José Fernandez-Nestosa, Surendra Dasari, Santosh Menon, Loren Herrera Hernandez, Rafael E Jimenez, Lori A Erickson, Antonio L Cubilla, Sounak Gupta
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., University of Alabama at Birmingham, Department of Pathology, Birmingham, AL, USA. Electronic address: ., Instituto de Patología e Investigación, Asunción, Paraguay. Electronic address: ., Facultad Politécnica, Universidad Nacional de Asunción, San Lorenzo, Paraguay. Electronic address: ., Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Department of Pathology, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: ., Instituto de Patología e Investigación, Asunción, Paraguay. Electronic address: ., Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA. Electronic address: .