Penile Cancer: Classification

Histology of penile carcinoma

Squamous cell carcinoma 95 %
  • Classic squamous cell carcinoma: 48-65%, with or without keratinization. Prognosis depending on grading: 30% deceased from the disease.
  • Basaloid squamous cell carcinoma (basaloid-squamous carcinoma): 4-10%, aggressive subtype with early lymphogenic metastasis; poor prognosisHPV high-risk types 16 and 18 (rarely also HPV low-risk types (e.g., HPV 6 and 11)Prognosis: >50% deceased from disease.
  • Condylomatous squamous cell carcinoma: up to 10%, HPV-associated, benign subtype, metastasis only in exceptional cases.
  • Verrucous squamous cell carcinoma: 3-8 %, benign subtype, metastasis only in exceptional casesPrognosis: good.
  • Papillary squamous cell carcinoma: 5-15 %, benign subtype, metastasis only in exceptional casesPrognosis: good
  • Sarcomatoid squamous cell carcinoma: 1-3 %, aggressive subtype.Early vascular metastasisEarly vascular metastasisPrognosis: 75 % deceased from the disease.
  • Adenosquamous squamous cell carcinoma: < 1%Good prognosis.
Other

Tumor stages of penile carcinoma according to the Union for International Cancer Control (UICC).

T Primary tumor
TX Primary tumor not assessed
T0 No evidence of primary tumor
Tis Carcinoma in situ
Ta Noninvasive verrucous carcinoma 1
T1 Tumor invasion of the subepithelial connective tissue.
T1a tumor invasion of subepithelial connective tissue without vascular invasion and is not poorly differentiated (T1G1-2)
T1b tumor invasion of subepithelial connective tissue with vascular invasion or poor differentiation (T1G3-4)
T2 Tumor infiltrates corpus spongiosum (corpus cavernosum) with or without infiltration of urethra (urethra)
T3 Tumor infiltrates the corpus cavernosum(s)/a with or without infiltration of the urethra
T4 Tumor infiltrates other adjacent tissue structures
N Regional lymph node involvement
NX Regional lymph nodes (LK) cannot be assessed
N0 No palpable or visibly enlarged inguinal LK
N1 Palpable unilateral mobile inguinal LK
N2 Palpable mobile and multiple unilateral or bilateral inguinal LK
N3 Fixed inguinal LK mass or pelvic lymphadenopathy (lymph node swelling , unilateral or bilateral
M Distant metastases
M0 No distant metastases
M1 Distant metastases

1 Verrucous carcinoma not associated with detructive invasive growth.

Pathologic classification

The pT category is the same as the T category. The pN category is based on biopsy or tissue after surgical excision.

pN Regional lymph nodes
pNX Regional lymph nodes (LK) cannot be assessed
pN0 No regional lymph node metastases
pN1 Metastases in one or two inguinal LKs
pN2 Metastases in >2 unilateral inguinal LK or bilateral inguinal LK.
pN3 Metastasis(s) to pelvic LK, unilateral or bilateral extralymphatic growth of regional LK metastases
pM Distant metastases
pM0 No distant metastases
pM1 Distant metastases

Histopathological grading

G Histopathological grading
GX Degree of differentiation cannot be collected
G1 Well differentiated
G2 Moderately differentiated
G3-4 Poorly differentiated/undifferentiated

The World Health Organization (WHO) pathologic differentiation of penile squamous cell carcinoma types is as follows:

  • HPV-dependent carcinogenesis of basaloid, warty, or similar mixed types of penile carcinoma.
    • Basaloid HPV-associated subtype (5-10% of cases).
  • Largely HPV-independent carcinogenesis of the usually, well-differentiated and keratinized squamous cell carcinomas (70-75% of cases).