Skin metastasis of squamous cell carcinoma of the penis: case report

¹Service of Urology, Military Hospital of Instruction Mohamed V, Hay Ryad, 10100 Rabat, Morocco

^&Corresponding author
Tariqi Reda, Service of Urology, Military Hospital of Instruction Mohamed V, Hay Ryad, 10100 Rabat, Morocco

Introduction    

Squamous cell carcinoma of the penis is a relatively rare disease with low incidence rates of approximately 0.5-1.0 per 100 000 person-years in Europe and the United States. Treatment of small cell carcinoma of the prostate (SCCP) is stage dependent and includes, for no distant metastatic SCCP, surgery of the primary lesion as well as regional lymph node dissection when indicated [1]. The majority of penile cancers are epithelial, with squamous cell histology accounting for 95% of cases. Other histologies, including basal cell carcinoma, melanoma, sarcoma, and adenocarcinoma, are rarer. Risk factors associated with the development of squamous cell carcinoma include human papillomavirus (HPV) [2], phimosis, smoking, and human immunodeficiency virus (HIV), whereas circumcision may be protective [3]. The correct tumor staging according to the TNM classification, histological type, tumor grade, lymphatic and vascular invasion are essential for treatment planning and establishing a prognosis. Survival in case of lymph node metastases is pejorative, it is approximately 50% at 5 years if they are invaded [4,5]. Disease recurrence after primary treatment for SCCp with curative intent is associated with a high mortality risk [6]. The objective of this work was to report about the occurrence of squamous cell carcinoma of the penis in a patient being treated for urothelial carcinoma, the outcome of which was marked by skin metastasis.

Patient and observation     

Mr. M.C a 75 years old patient, married, father of 3 children, military withdrawal and living in Fez. He is a chronic smoker and has no medical or surgical history. Patient initially consults in 2015 for macroscopic hematuria without other associated signs. Pelvic ultrasonography showed a right and left lateral bladder lesion and was completed by a uroscan, in favor of a multifocal bladder urothelial tumor. The patient benefited from a complete and deep Trans-urothelial resection with a pt1 G2 urothelial carcinoma on anatomopathological examination. A second look realized one month later, showed a multifocal recurrence graded pt2 in anatomopathology. In front of a negative extension assessment, the patient benefited from a radical cysto-prostatectomy with bilateral ilio-obturator scouring and Briker-type urinary diversion. The definitive anatomopathological examination was in favor of a high-grade urothelial carcinoma classified pt3 N0M0R0. Two years later, the patient experienced pain in the penis with an induration of the left corpus cavernosum in its proximal part on a normal penile skin and free ganglionic areas. A penile ultrasound scan is performed and shows a fibrosis which gives an induration aspect, completed by a pelvic MRI without abnormality and a thoraco-abdomino-pelvic CT scan without particularity.

In front of the persistence of the induration at the level of the penis, FDG-PET/CT was requested, objectivizing an intense penile pathological hypermetabolism, extended over a length of 73.7mm, small bilateral inguinal ganglion foci, weakly hypermetabolic and a moderate hypermetabolism of the middle 1/3 of the thoracic oesophagus (Figure 1) gastroesophageal endoscopy with multiple biopsies and subsequent anatomopathological studies did not detect histological signs of malignancy. As urethroscopy with biopsy was not possible due to urethral meatus stenosis and a correct operability assessment and a favorable psychiatric opinion, and after multidisciplinary consultation, the patient underwent a penectomy with bilateral orchiectomy (Figure 2). The anatomopathological result was in favor of a moderately differentiated and infiltrating squamous cell carcinoma of the corpus cavernosum pT3R0 with three lesions corresponding to condyloma of low-grade dysplasia. The procedure was completed secondarily by bilateral inguinal scraping, 2N out of 11 positives on the right, without capsular effraction, classified as pN1 (Figure 3, Figure 4,, Figure 5). The multidisciplinary consultation decision in front of this squamous cell carcinoma of the penis classified pT3pN1R0 was a standard surveillance. Six months later, the patient developed multiple nodular, budding lesions on erythematous plaque on the anteromedial side of the right thigh. A biopsy with histological analysis confirmed the dermal metastatic localization of the squamous cell carcinoma (Figure 6). The patient subsequently received cisplatin- 5FU based chemotherapy, which was complicated after the second session by a proximal pulmonary embolism causing the patient's death 16 hours after admission to intensive care.

Discussion     

In the literature and according to the Jean-Nicolas Cornu et al. series, the average age was 58.8 years [7]. In the Moroccan study by In. Nouri et al. the average age was 60.5 years [4]. Our patient's age of discovery is consistent with the average age described in the literature, where incidence increases after the age of 50 [8, 9]. The site of the lesion is usually reported distally involving the prepuce, glans and the balano-preputial fold, unlike in our case where the location was more proximal. The locoregional extension is mainly lymphatic towards the inguinal lymph nodes, which conditions the prognosis [10]. It has been well established that penile squamous cell carcinoma (SCC) can arise from chronic inflammatory conditions as well as infection with human papillomavirus (HPV) [11]. A recent meta-analysis found that 50.8% of penile cancer cases were HPV related and that the predominant oncogenic HPV type was HPV16.7 [12]. In our case, we note the presence of the condylomas in anatomopathological analysis. Another contributing factor is Bowen's disease, which appears in the same age group. It corresponds to squamous cell carcinoma in situ, with a risk of progression to invasive squamous cell carcinoma in the absence of treatment [13]. According to the Cancer Research Committee of the French Association of Urology (CCAFU), there is no recommendation that determines the indication between radiological tests, such as ultrasound, CT scan of the abdomen and pelvis, and MRI. The 18F-FDG-PET/CT may be useful in patients with SCCP and metastatic inguinal nodes, to assess the response to chemotherapy and in the rare cases of cutaneous metastases to detect other unsuspected metastases [14]. Unresolved controversies about which imaging procedures should be included in the diagnosis and staging of the SCCP. The European Association of Urology (EAU) recommends MRI with pharmacologically induced erection by injection into the corpora cavernosa of 10 mg of prostaglandin E1 2 in order to determine the local extent of the tumor. In our case, the patient has a history of radical cysto-prostatectomy for a bladder tumor infiltrating the muscle, which influenced the choice of complementary tests. First of all, the patient benefited from an ultrasound of the penis which only showed induration and a thoraco-abdomino-pelvic CT scan with no particularities, followed by an inconclusive penile and pelvic MRI scan. This led us to perform a positron emission tomography (PET) scan of the fluorodeoxyglucose (FDG), which objectifies a pathological penile hypermetabolism and bilateral inguinal ganglion foci.

The therapeutic model according to the recommendations of the Cancer Research Committee of the French Association of Urology (CCAFU) is the most followed in the literature. It is made in adequacy with the clinical presentation, the lymph node status and the local-regional and remote extension. Inguinal lymph node dissection (ILND) occupies a central role in the management of non-metastatic penile cancer [15,16], and is used either for diagnostic or therapeutic purposes [17,18]. The National Comprehensive Cancer Network and the European Association of Urology guidelines recommend ILND or dynamic sentinel lymph node excision in patients with squamous cell carcinoma of the penis (SCCP) starting from high-grade T1 stage and beyond [18]. Our patient underwent a penectomy with bilateral orchiectomy initially, followed by bilateral inguinal excision and was classified as pT3pN1M0RO and placed under surveillance. The skin metastases of SCCP, regional as well as distant, are rare, have a poor prognosis and are often associated with metastases to other organs [10,12]. Of the 111 cases of cutaneous metastases secondary to neoplasms of the genitourinary system collected in the review work of Mueller et al. [19], only one case of penile carcinoma is included. The visceral malignancies that most frequently lead to cutaneous metastases arise from breast, lung, colon and ovarian cancer in women, while in man they correspond to colon and head and neck. According to the study of Rieken et al. [6], a shorter time from surgery to recurrence would be associated with a shorter time from recurrence to death. Data from 314 patients from centers treated between 1949 and 2012, median time from surgery to disease recurrence was 10.5 months, 108 patients died of SCCP and 41 patients died of causes other than SCCp. The 1-year risk of death from cancer was 20% for patients who recurred at 1 year. The time from surgery to disease recurrence is an independent predictor of cancer specific mortality CSM in patients with SCCp recurrence. The probability of cancer specific death was significantly higher in patients recurring at the first year after surgery compared with patients recurring at 3 and 5 year. The early occurrence of distant recurrences, which are associated with a poor prognosis [20]. Subsequently, our patient developed a skin metastasis 6 months after penectomy and was referred for chemotherapy and died shortly after the second session.

Conclusion     

Squamous cell carcinoma of the penis is a rare male malignancy and has a heterogeneous presentation, which explain the lack of systematized coverage. Node metastasis is associated with a severe prognosis and recurrence after penectomy is associated with a high risk of mortality. The skin metastases of SCCP, regional as well as distant, are rare, have a poor prognosis and are often associated with metastases to other organs.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

All the authors have read and agreed to the final manuscript.

Figures     

Figure 1: exploration 18F-FDG PET/CT showing: intense pathological hypermetabolism of the penis, extended over a length of 73.7mm, moderate hypermetabolism of the middle 1/3 of the thoracic oesophagus and weakly hypermetabolic bilateral inguinal ganglion foci

Figure 2: operative specimen

Figure 3: peroperatory images of an inguinal lymph nodes dissection. A) right dissection; B) left dissection

Figure 4: lymph node specimen. A) right dissection; B) left dissection

Figure 5: post-operative image

Figure 6: dermal lesions on the anteromedial side of the right thigh in favor of skin metastasis of squamous cell carcinoma of the penis

References