Squamous cell carcinoma of the penis: a case report

Clinical History

A 65-year-old patient was affected by severe fimosis. Biopsy revealed squamous cell carcinoma (SCC) of the penis. The patient was referred to our department for staging and a magnetic resonance imaging (MRI) examination of the penis was performed.

Imaging Findings

MRI (Fig. 1) confirmed the presence of an infiltrating lesion with irregular margins circumferentially involving the glans penis. The lesion showed marked contrast enhancement partially extending to the left corpus cavernosum. A subcentimetric (7mm) left inguinal lymph node was also found without evidence of enlarged pathological pelvic lymph nodes.
The patient underwent partial penectomy. Histophatologic examination of the surgical specimen revealed well-differentiated keratinising squamous cell carcinoma with lymphovascular invasion, free resection margins, and no invasion of urethra and corpora cavernosa (T1bNxG1).
Two months later, a follow-up MRI examination (Fig. 2) showed bilateral inguinal lymph nodes, the largest measuring 12x10mm in its transverse diameters. The patient underwent bilateral inguinal lymphadenectomy, and pathological examination of the resected lymph nodes revealed metastasis in 2 out of 25 lymph nodes.

Discussion

Squamous cell carcinoma of the penis is a relatively rare malignancy, accounting for approximately 0.4–0.6% of all malignancies diagnosed among men in the USA and Europe, and 10% of cases diagnosed in some African and South American countries [1]. The lowest incidence has been reported in Israeli Jews, who are routinely circumcised at birth [2].
Penile cancer is most commonly diagnosed in men aged 50–70 years. However, in 22% of cases SCC is diagnosed in men younger than 40 years [3].
Factors known to be associated with a higher risk of penile carcinoma include age, poor socioeconomic status, smoking, multiple sexual partners, chronic balanitis and inflammation, phimosis, and redundant prepuce [4]. Circumcision carried out early in the patient’s childhood is considered a protective factor. Further investigations showed that the pathogenesis of penile carcinoma could be correlated with human papilloma virus [5], specifically subtypes 16 and 18.
In most patients the clinical presentation is pruritus and pain; other presenting complaints are bleeding or foul smelling discharge. The lesion can be in the form of a lump or nodule (47%), an ulcer (35%), or erythematous lesion (17%) [6]. The most common lesion sites are the glans penis (34.5%) and the prepuce (13.2%) [7].
About two thirds of patients present with a localised lesion on the penis. Ultrasound or MRI may be useful in men with large tumours to evaluate the anatomical relationship with the surrounding structures.
Either CT or MRI can be used for lymph node staging based on size and shape criteria. However, MRI allows assessing functional aspects of lymph nodes. Diffusion-weighted imaging (DWI) is another promising MRI technique, which does not rely on the administration of contrast material [8].
Localised disease can be managed by surgical resection (partial or total penectomy) or penis-preserving surgery and radiotherapy. Prophylactic localised inguinal lymphadenectomy may improve survival.
In advanced cases, surgery with or without radiation is often used for palliation and local disease control. Metastases may involve distant lymph nodes, lung, liver, brain and bone, and is managed with chemotherapy. In any case, treatment of invasive SCC is aggressive and can leave physical and psychological sequelae. The overall carcinoma-related death rate among patients with SCC is 41% and survival appears to be influenced by age, race, and stage at diagnosis [3, 6].

Differential Diagnosis List

Final Diagnosis

Squamous cell carcinoma of the penis

URL:	https://www.eurorad.org/case/10561
DOI:	10.1594/EURORAD/CASE.10561
ISSN:	1563-4086