Basaloid squamous cell carcinoma of the penis with papillary features: a clinicopathologic study of 12 cases

Am J Surg Pathol. 2012 Jun;36(6):869-75. doi: 10.1097/PAS.0b013e318249c6f3.

Abstract

There are 3 distinct variants of penile squamous cell carcinoma frequently associated with human papillomavirus (HPV): basaloid, warty-basaloid, and warty carcinomas. Considering the high incidence rates of penile cancer in some countries, a large international study was designed to evaluate the presence of HPV, its genotype distribution, and its association with histologic types of penile cancer. In this international review of >900 cases, we found a group of highly distinct papillary neoplasms composed of basophilic cells resembling urothelial tumors but frequently associated with HPV. Macroscopically, tumors were exophytic or exoendophytic. Microscopically, there was a papillomatous pattern of growth with a central fibrovascular core and small basophilic cells lining the papillae. Positivity for HPV was present in 11 of 12 tumors (92%). Single genotypes found were HPV-16 in 9 tumors and HPV-51 in 1 tumor. Multiple genotypes (HPV-16 and HPV-45) were present in another case. Overexpression of p16 was observed in all cases. Uroplakin-III was negative in all cases. The differential diagnosis was with basaloid, warty-basaloid, warty, and papillary squamous cell carcinoma and with urothelial carcinomas. Local excision (4 cases), circumcision (3 cases), or partial penectomy (5 cases) were preferred treatment choices. Tumor thickness ranged from 1 to 15 mm (average, 7 mm). Two patients with tumors invading 11 and 15 mm into the corpus spongiosum developed inguinal nodal metastasis. Of 11 patients followed up (median 48 mo), 7 were alive with no evidence of metastatic disease, 3 died from causes other than penile cancer, and another died postoperatively. This morphologically distinct tumor probably represents a papillary variant of basaloid carcinomas (papillary-basaloid carcinomas). Unlike typical basaloid carcinomas, the overall prognosis was excellent. However, deeply invasive tumors were associated with regional nodal metastasis indicating a potential for tumor-related death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma, Papillary / metabolism
  • Adenocarcinoma, Papillary / pathology*
  • Adenocarcinoma, Papillary / therapy
  • Adenocarcinoma, Papillary / virology
  • Adult
  • Aged
  • Aged, 80 and over
  • Alphapapillomavirus / genetics
  • Alphapapillomavirus / isolation & purification
  • Biomarkers, Tumor / metabolism
  • Combined Modality Therapy
  • Cyclin-Dependent Kinase Inhibitor p16 / metabolism
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Invasiveness
  • Neoplasms, Squamous Cell / metabolism
  • Neoplasms, Squamous Cell / pathology*
  • Neoplasms, Squamous Cell / therapy
  • Neoplasms, Squamous Cell / virology
  • Papillomavirus Infections / metabolism
  • Papillomavirus Infections / pathology*
  • Papillomavirus Infections / virology
  • Penile Neoplasms / metabolism
  • Penile Neoplasms / pathology*
  • Penile Neoplasms / therapy
  • Penile Neoplasms / virology

Substances

  • Biomarkers, Tumor
  • Cyclin-Dependent Kinase Inhibitor p16