Squamous cell carcinoma of the scrotum - still an occupational hazard.

Squamous cell carcinoma (SCC) of the scrotum was one of the first occupational diseases to be described, and acquired its eponym from Sir Percivall Pott. The condition has now become rare owing to the establishment of industrial health norms. A 45-year-old male with a history of long-term exposure to petrochemicals presented to our institution with a scrotal lesion and underwent wide-local excision of the same. Histopathology revealed well-differentiated SCC involving the epididymis. Treatment options included excision with ilio-inguinal bloc dissection (in the event of lymphadenopathy) with subsequent chemotherapy and/or radiotherapy. Tumors following occupational exposure thus continue to contribute to the rapidly decreasing incidence of scrotal carcinoma.

INTRODUCTION

The myriad synonyms of squamous cell carcinoma (SCC) of the scrotum are testament to the gradual evolution of the etiopathological associations of this condition. It was, in fact, the first occupational disease to be described when Percivall Pott discovered its unusually frequent occurrence in chimney sweeps.[1] Throughout history, the three main occupational groups that have been at risk are chimney sweeps, those who work with distillates of coal, and those who work with mineral oil.[2] This disease is considered rare in the present era, with occupation-related cases being even more uncommon. Here, we present the case of SCC of the scrotum in a petrochemical worker.

CASE REPORT

A 45-year-old man presented to our outpatient department with the complaints of a large bleeding lesion on the scrotum with copious foul-smelling discharge. He had noted a small 2 × 1 cm swelling at the same site 3–4 months ago, which enlarged over time and did not seem to respond to alternative medicines obtained from a local practitioner. The onset of discharge and recurrent bouts of bleeding from the lesion compelled him to visit the hospital. There was no history of febrile episodes, symptomatology suggestive of sexually-transmitted diseases, promiscuity, or other high risk behaviors. There were no comorbidities or significant illness/hospitalization in the past. Occupational history was significant for a long-term proximity (20-22 years) to petrochemicals during his work as a mobile-oil dealer.

Examination revealed an irregular 7 × 4 cm ulcero-proliferative lesion oriented along the longitudinal axis of the scrotum and occupying the left hemiscrotum [Figure 1]. The ulcer was non-tender, with everted margins, a depth of 4 mm and appeared to be free from the underlying testis [Figure 2]. There was no associated inguinal lymphadenopathy. The rest of the physical examination was unremarkable. A wedge biopsy revealed well-differentiated SCC. Contrast-enhanced computed tomography (CECT) of the abdomen and pelvis did not show any lymphatic or distant metastasis.

Figure 1

Ulcero-proliferative lesion over the left hemiscrotum

Figure 2

Everted margins characteristic of squamous cell carcinoma

The patient underwent a wide local excision with 2-cm margins under spinal anesthesia. Peroperatively, the base of the ulcer was found to be adherent to the mobile cauda epididymis. The patient had not consented for orchidectomy, and the epididymis was partially resected in order to mobilize the growth. The wound was closed primarily. The histopathology report showed well differentiated SCC with involvement of the epididymis. The patient has been planned for a left orchidectomy and hemiscrotectomy with subsequent chemoradiation therapy.

DISCUSSION

It took more than a century to establish the carcinogenicity of tar and tar-based products with Kennaway[3] and later Cook experimenting extensively with synthetic hydrocarbons after World War I. Cook et al. then isolated a highly carcinogenic crystalline compound from the distillate of two tons of pitch and showed this to be 3, 4 benzpyrene (benzo (a) pyrene).[4] The case for mineral oil and derivatives as carcinogens became stronger when, apart from “Chimney sweeps cancer”, other professionals such as mule spinners, shale oil workers, and engineering workers were found to be at risk for epidermoid carcinoma of the scrotum and came under the purview of various industrial compensation acts.[2] Apart from petrochemical compounds, various other non-occupational factors have been noted such as poor hygiene, PUVA (Psoralen with Ultraviolet therapy used to treat psoriasis)[5], Human papilloma virus type 18,[6] and radiotherapy. Other associations such as chronic lymphedema[7] and chronic inflammation[8] remain to be established.

SCC is only one of the pathological types of neoplasms affecting the scrotum; the others being basal cell carcinoma, melanoma, sarcoma, Paget's disease, adnexal skin tumors, and metastatic tumors. The demographic has changed gradually from the 2nd or 3rd decade in Pott's time to the 5th to 7th decades now. Presentation is usually as a painless solitary wart or nodule. A delay in presentation due to ignorance or embarrassment has been noted worldwide with most patients seeking help only after the lesion is advanced, ulcerated, or associated with nodal metastases. McDonald[9] and Ray and Whitmore[10] have found that the lag period between patient awareness of the lesion and presentation was 3.3 years and 26 months, respectively. The tumor rarely involves the scrotal contents or penis, and distant metastasis is unusual.[10] The pubic bone may be involved by direct extension. Spread is to the inguinal nodes, which may be unilateral, bilateral, or crossed, iliac nodes, the para-aortic nodes, and may also reach the lungs.[11]

Diagnosis is conclusively established by biopsy. The patient may also require fine-needle aspiration cytology in the event of palpable inguinal lymphadenopathy. As demonstrated by Johnson, the overall survival in those with SCC as opposed to any other histological type is poor.[12] It is dependent on locoregional and distant spread, with a 5-year survival rate of 25% in those with inguinal lymphadenopathy and almost zero survival in iliac nodal metastases. Also, a high incidence of other primary tumors has been noted in scrotal carcinoma patients.[10] Appropriate investigations to exclude any other internal malignancy and distant metastasis include abdominopelvic ultrasonography and CECT of the abdomen and chest. Magnetic resonance imaging (MRI) is also of late being considered a useful tool in the differential diagnosis of scrotal conditions.[13]

Surgical excision with at least a 2-3 cm wide margin has been established as the standard of care. Resection of scrotal contents en-bloc is necessary in the event of involvement by the primary,[10] as was the case with our patient. Options for resurfacing of the exposed scrotal contents include primary closure, local thigh flaps, myocutaneous gracilis or adductor minimus myocutaneous flaps, heterologous fascia grafts, ipsilateral orchidectomy, placement of the testis in a subcutaneous pouch in the anteromedial thigh, or even contralateral testicular transposition.[14] The option selected should depend on the individual being treated and the proficiency of the surgeon.

As regards management of the clinically negative or positive groin, the picture remains unclear and has been encapsulated well by Azike in his 2009 review.[14] The controversy has echoes of the debate that still rages on for penile carcinoma. However, due to the extremely low incidence of the disease, it will be difficult to conduct randomized trials to establish the superiority of any one protocol over the other. For the same reason, it will be difficult to agree on chemoradiation schedules when their very use is anecdotal. Both adjuvant and neo-adjuvant regimes have been used, such as the four courses of methotrexate, bleomycin, and cisplatin with radiotherapy used by Aria et al. after resection and thought to increase disease-free survival.[15] The patient should be followed up indefinitely.

There is no doubt that the betterment of safeguards in petrochemical and associated industries with higher standards of sanitation and hygiene has diminished the cases of scrotal SCC due to occupational exposure. This patient will remain at best an anomaly in the 21st century where only about 10 cases per year[16] and recently 2-3 per year[17] have been recorded (United States data). Patient education as well as vigilance on the part of the physician will go a long way in the early detection of such potentially lethal work-related conditions.