HPV positive primary scrotal and perianal squamous cell carcinoma with locoregional reconstruction

Scrotal and perineal squamous cell carcinoma (SCC) is a rare, aggressive skin cancer typically seen in older men.1, 2 Risk factors include chronic skin irritation or inflammation, ultraviolet radiation exposure, smoking, human papilloma virus (HPV) infection, and a history of precancerous or cancerous skin lesions.1, 2 Diagnosis is made by biopsy, while imaging modalities such as CT or MRIs can determine cancer's extent.1 Treatment depends on the cancer stage and patient health, with surgery being the mainstay.1 Surgical resection is limited to the primary tumour in the early stages, while advanced stages require radical resection involving removal of the testis, lymph nodes (LN), and surrounding tissue.2 Recommendations for surgical margins differ in the literature, with most cutaneous SCC management guidelines starting at a 6 mm margin for large poorly-defined lesions while some authors recommend 2-3 cm.3-5 Inguinal LNs management is controversial due to low incidence rates and limited studies.1, 2 Current recommendations involve a risk-based approach using sentinel LN biopsy.1, 2, 5 Adjuvant therapy with radiation and/or chemotherapy may be used to reduce recurrence risk.1 Prognosis is typically unfavourable, with 5-year survival rates of 40%–60%.2 Poor prognosis correlates with late-stage diagnosis, high tumour grade, and low cell differentiation.2 A 48-year-old male with a 7-month history of an enlarging ulcerating skin lesion of the scrotum and perineum was referred for intervention. The patient was a long-term smoker with no history of occupational/radiation exposure or chronic irritation/inflammation. A 10 cm large fungating mass with serous discharge and potential infection was observed, with no clear involvement of the anus, rectum, or testicles (Fig. 1). Bilateral inguinal lymphadenopathy was noted. His initial biopsy established a HPV negative SCC while the pre-operative CT chest/abdomen/pelvis showed no metastatic or nodal disease. Positron emission tomography demonstrated an avid scrotal lesion and low avidity uptake in left inguinal LN. CT-guided biopsy yielded no nodal tissue. MRI confirmed the large ulcerated left scrotal/perineal SCC and borderline enlarged left inguinal LNs. The multidisciplinary team consensus was for bilateral inguinal LN dissection without neoadjuvant treatment or preoperative antibiotics. The patient underwent wide local excision with 10 mm margins, bilateral superficial/deep inguinal LN dissection and a vertical rectus abdominus musculocutaneous (VRAM) pedicled flap in a combined urological and plastics procedure. The SCC was excised en-bloc, and frozen sections confirmed negative margins (Fig. 2). Postoperative complications included a day-zero groin dissection haematoma evacuation and day-11 bilateral inguinal seroma drainage. Histopathology confirmed HPV-associated (p16 positive) SCC with clear surgical margins and no lymphovascular or perineural invasion. Bilateral inguinal LNs were negative for malignancy (Staging – T4 N0 M0). There was no evidence of recurrence with good cosmetic results at the 3 months follow up. In the realm of oncological perineal defect reconstruction, achieving an optimal outcome necessitates the utilization of adequate skin coverage and well-vascularised, non-irradiated tissue to adequately occupy the dead space.6 Although secondary intention healing, negative pressure wound therapy, and skin grafting are occasionally applicable for small defects, contemporary practices favour flap reconstruction. Skin grafts particularly in the perigenital region, present challenges due to the high bacterial load, often culminating in graft loss, prolonged healing periods, suboptimal scar quality, and contractures that may disrupt normal urination or coitus.7 In this specific case, the patient's extensive history of smoking amplified the risk of graft failure. Additionally, the site's volume deficit and high bacterial presence rendered primary closure unsuitable for the defect. The VRAM flap provides numerous advantages, including a long robust pedicle, significant volume and surface area, relative ease of harvest, and a low propensity for necrosis.6 The strategic tunnelling of the VRAM flap minimizes the distance traversed by the pedicle. However, this process mandates meticulous technique to preclude potential pedicle kinking or twisting, particularly when repositioning the patient from a supine to prone orientation (Fig. 3). HPV p16 scrotal SCC is an uncommon aetiology and supports the role of HPV prevention by immunization amongst males. Although ultimately histologically negative, the decision for bilateral inguinal LN dissection was based on clinical and radiological evidence of positive LNs. While many alternative reconstructive methods exist, the VRAM locoregional pedicled flap was robust and yielded a good cosmetic result. This case highlights the significance of early intervention and timely management of scrotal lesions and serves as a reminder for patients who may be unaware of their risk factors to promptly seek medical advice if they notice any suspicious scrotal lesions. Open access publishing facilitated by University of New South Wales, as part of the Wiley - University of New South Wales agreement via the Council of Australian University Librarians. Damien Gibson: Conceptualization; data curation; writing – original draft; writing – review and editing. Ishith Seth: Conceptualization; writing – review and editing. Wenjie Zhong: Formal analysis; writing – review and editing. Matthew Jennings: Data curation; writing – review and editing. Benjamin Sebastian: Writing – review and editing. Alex Cameron: Writing – review and editing. Rohan Hall: Supervision; writing – review and editing.