Figure 1: Sagittal T2 weighted image demonstrates a large mass in the right scrotum with central areas of necrosis. This mass demonstrates invasion into the base, proximal and mid-penis (corpus spongiosum and right corpus cavernosum). The testes are intact (not shown).

Figure 2: Coronal T2 weighted image again demonstrates a large mass in the right scrotum. There are enlarged lymph nodes in the right inguinal region with small areas of central necrosis. Note that the signal characteristics of the lymph nodes are similar to that of the primary mass.

Squamous cell carcinoma of the scrotum.

Malignant tumors of the scrotum are rare in the United States, with approximately 10 new cases per annum reported in 1976. Scrotal carcinoma has been and is almost 20 times more common in the United Kingdom than in the United States. The most common carcinoma to involve the scrotum is squamous cell carcinoma.

Squamous cell carcinoma (SCC) of the scrotum was one of the first cancers that was directly linked with a specific occupation. Sir Percivall Pott in 1775 noted a high incidence of squamous cell carcinoma of the scrotum in chimney sweepers. Since then other occupations have been associated with an increased incidence of scrotal carcinoma including paraffin or shale oil workers, mule (cotton) spinners, machine operators in engineering, petroleum wax pressman, workers in the screw-making industry, and automatic lathe operators. Other factors related to scrotal SCC are social class, with laborers being at a higher risk, race (white men > black men), and variations in hygiene. Today, squamous cell carcinoma is a very uncommon neoplasm. However, new potential etiologies have emerged. PUVA ( psoralen (P) and long-wave ultraviolet radiation (UVA)), used to treat psoriasis, has recently been shown to increase the incidence of both penile and scrotal malignancies. The risk of squamous cell carcinoma of the genitalia is 5-15 times that of other parts of the body. A study by Stern et al. demonstrated that the risk of invasive squamous cell carcinoma of the genitalia among men exposed to high-intensity PUVA is nearly 300 times that of the general population. Also, Burmer et al. documented an association between scrotal carcinoma and Human Papilloma Virus (HPV) type 18, while areas of dysplasia were associated with either HPV type 18, 16, or 6/11.

Men with scrotal SCC usually present during the 5 th to 6 th decade of life, with the average age at presentation in the fifties. Patients who have industrial exposure require prolonged contact and there is a latency period before the cancer develops. Scrotal SCC most frequently presents as a solitary lesion. The early lesion is a slowly growing pimple, wart, or nodule on the anterolateral aspect of the scrotum, and excluding occupational exposure, there appears to be no predilection for a side. This lesion persists for approximately 6 months before ulcerating. Most patients have the initial lesion for 8-12 months before seeking medical assistance and diagnosis. Invasion of the scrotal contents or of the penis has been observed in patients with advanced lesions. At the time of presentation, 40-50% of patients have ipsilateral inguinal adenopathy, and approximately half of these men will have metastases in the surgical specimens. Multiple tumors are found in as many as 25% of cases.

Various malignant and benign lesions of the scrotum must be differentiated from squamous cell carcinoma. The benign lesions include cutaneous nerves, sebaceous cyst, eczema, psoriasis, oil folliculitis, sclerosing lipogranuloma, hemangioma, lymphangioma, and neurilemoma. Benign diseases that may cause scrotal lesions include unusual presentations of secondary and tertiary syphilis, tuberculous epididymitis with a draining sinus, and periurethral abscess. Malignant lesions that involve the scrotum include basal cell carcinoma, malignant melanoma, extramammary Paget's disease, erythroplasia of Queyrat, various sarcomas, and metastatic lesions.

Stage A1 Localized to scrotal wall
Stage A2 Locally extensive tumor invading adjacent structures (testis, spermatic cord, penis, pubis, perineum)
Stage B Metastatic disease involving inguinal lymph nodes only
Stage C Metastatic disease involving pelvic lymph nodes without evidence of distant spread
Stage D Metastatic disease beyond the pelvic lymph nodes involving distant organs.

The treatment of choice for primary scrotal SCC is wide local excision with a 2 cm margin with resection of the skin and underlying dartos muscle in the region. Sentinel node biopsy and ilioinguinal or inguinal lymphadenectomy are also recommended in patients with suspected lymph node metastases. Small and medium sized tumors can be excised and the scrotal wall approximated without difficulty. However, large cancers require other measures, such as placing the testes subcutaneously in the thigh or femoral region, using local thigh flaps to close the defect, or using a split-thickness skin graft to cover the scrotum. Local recurrence, most often adjacent to or around the area of the previously excised lesion, secondary to new foci of carcinoma or residual carcinoma is seen in 20-40% of patients. For low stage lesions, laser therapy has been used to treat the local lesion with the possible advantage of a better cosmetic result. Radiation therapy frequently has a minimal role in the treatment of squamous cell carcinoma of the scrotum and is used as a last resort for non-resectable residual or recurrent disease, although without significant effect.

Patients with squamous cell carcinoma of the scrotum typically have a poor survival in spite of surgical intervention, possibly because most patients present at 8-12 months when involvement of lymph nodes and distant metastases has occurred. Patients with Stage A1 disease have approximately a 75% or better chance for long- term survival. However, for patients with stage C or stage D disease, the long-term prognosis is poor.

References:

1. Scrotal Malignancies: The University of Iowa Experience and a Review of the Literature. Urology. 1985; 26(4): ************
2. Stern RS, and R Lang. Non-melanoma skin cancer occurring in patients treated with PUVA five to ten years after first treatment. Journal of Investigative Dermatology. 1988; 91(2):120-4.
3. Stern RS, and R Lang. Non-melanoma Skin Cancer Occurring In Patients Treated With PUVA Five To Ten Years After First Treatment. Journal of Investigative Dermatology . 1988; 91(2):120-4.
4. Schellhammer PF , Jordan GH, et al. Premalignant Lesions and Nonsquamous Malignancy of the Penis and Carcinoma of the Scrotum. Urologic Clinics of North America . 1992; 19(1): ************
5. F.C. Lowe. Squamous-Cell Carcinoma of the Scrotum. Urologic Clinics of North America . 1992; 19(2): 397-405.
6. Burmer GC, True LD, and JN Krieger. Squamous Cell Carcinoma of the Scrotum Associated With Human Papillomaviruses. Journal of Urology. 1993; 147: 374-377.
7. Taniguchi S, Furukawa M, et al. Squamous Cell Carcinoma of the Scrotum. Dermatology. 1996; 193: 253-254.
8. Muglia V, Tucci S, et al. Magnetic Resonance Imaging of Scrotal Diseases: When It Makes The Difference. Adult Urology. 2002; 59: 419-423.