Diagnosis of penile cancer involves clinical appearance and history of penile cancer, imaging techniques such as ultrasonography, MRI, CT and PET scan, and penile biopsy.
Due to poor public awareness and feelings of shame, the majority of penile cancer patients have a delayed presentation which decreases the success rate of treatment and cure. The diagnostic procedures and techniques used for penile cancer diagnosis include:
Clinical appearance and history
Primary tumors of the penis are clinically visible if they appear as external lesions. In fact, the diagnostic pathway identifies histological subtypes and degree of involvement of the primary lesion and assesses metastatic disease in local or distal lymphatics. Most penile cancers are squamous cell carcinoma (SCC) (95%), which may be clinically suspicious in appearance and also in location. However, the physical position and superficial appearance of the penis are two distinct features that give rise to clinical suspicion and immediate investigation. These lesions are usually painless and may be associated with a purulent discharge under the foreskin1.
Unlike exophytic lesions, ulcerative glans or foreskin lesions have a broad differential diagnosis and should not be diagnosed as cancer of the penis unless histologically confirmed by incision or perforation biopsy to detect bigger and larger glans lesions. Clinical evaluation of the primary lesion to assess the extent of local infection in the surgical plan. The size, location (eg, glans, liver or foreskin) and also the morphology of the lesion should be evaluated in clinical examination.
Imaging is essential for determining the stage of cancer, for surgical planning, and also for identifying missed lesions in the corpus cavernosum. Cross-sectional imaging, such as CT, determines the disease stage at diagnosis and allows the identification of abnormal inguinal or pelvic lymphadenopathy and distant metastatic disease. In fact, penile ultrasound and MRI are the recommended types of primary lesions.
The main role of ultrasound examination in diagnostic work is the evaluation of inguinal lymph nodes. Fine needle aspiration (FNA) may be performed on morphologically abnormal lymph nodes. Alternatively, MRI ultrasonography can visualize the extent of cavernous or spongiosal infiltration using primary tumor imaging. Based on the final histological analysis, ultrasonography provides a more accurate estimate of the extent of cavernous infiltration than clinical palpation2.
Clinical and histological evaluation of the primary tumor correlates with penile MRI in the presence of pharmacologically induced erection3. However, comparison with histological analysis showed progressively better stage-specific sensitivity and specificity of MRI assessments according to tumor stage. Therefore, penile MRI is a useful aid in planning primary surgery, especially if the degree of cavernous infection is unclear and there is a need to adjust the extent of surgical resection to include the distal body when the tumor penetrates the tunica albuginea.
CT and PET/CT
Because of the potentially significant incidence of inguinal lymphadenectomy (ILND) and pelvic lymphadenectomy (PLND), the search for imaging techniques that can accurately identify PSCC lymphatic metastases continues8.
A diagnostic biopsy is generally considered necessary for the treatment of solid tumours. However, the penis is an external organ, and large tumors of the vulva are clinically evident. FNA, which confirms intralymphatic PSCC in the presence of apparent inguinal lymph nodes, denies the need for penile biopsy in the presence of clinically evident PSCC. As a result, treatment decisions in patients with metastatic disease do not change. However, ulcerative or inflamed lesions are sometimes secondary to benign disease. Foreskin PSCC lesions are easily removed by circumcision, which provides diagnostic biopsy and also final treatment4.
- 1.Favorito LA, Nardi AC, Ronalsa M, Zequi SC, Sampaio FJB, Glina S. Epidemiologic study on penile cancer in Brazil. Int braz j urol. Published online October 2008:587-593. doi:10.1590/s1677-55382008000500007
- 2.Agrawal A, Pai D, Ananthakrishnan N, Smile S, Ratnakar C. Clinical and sonographic findings in carcinoma of the penis. J Clin Ultrasound. 2000;28(8):399-406. doi:3.Petralia G, Villa G, Scardino E, et al. Local staging of penile cancer using magnetic resonance imaging with pharmacologically induced penile erection. Radiol Med. 2008;113(4):517-528. doi:10.1007/s11547-008-0273-64.Thomas A, Necchi A, Muneer A, et al. Penile cancer. Nat Rev Dis Primers. 2021;7(1):11. doi:10.1038/s41572-021-00246-5