Background:
Squamous Cell Carcinoma (SCC) of the Vulva are associated with later presentation, more advanced disease, and a propensity to metastasise at the time of diagnosis when compared with similar cutaneous SCC in other sites of the body. Increased tumour staging requires more radical surgical treatment and increases the likelihood of requiring post-operative adjuvant radiotherapy. Advanced tumours generally spread via lymphatics to the lymph nodal basins which is associated with worse prognosis. Dermal in-transit metastases are a rare but aggressive clinical phenomenon which have been reported in other sites of the body from cutaneous SCC and demonstrate dermal lymphatic halting and localised growth in the subcutis. This has rarely been described in the vulval literature, with only 16 cases reported to date1. However in all reported cases the prognosis was very poor (with some studies stating a 13% 5 year survival rate2) and therefore recommended treatment is a combination of surgery and adjuvant radiotherapy.
Clinical Case:
A 78 year old woman was referred to our gynaecology oncology unit with a 4cm vulval SCC and underwent an anterior radical vulvectomy and bilateral inguinofemoral lymph node dissection. Histopathology results diagnosed Stage 1B Grade 2 HPV associated SCC (no LVSI, DOI 10mm, clear of margins) with 0/16 lymph nodes involved. In addition, there was an isolate subcutaneous metastatic deposit (3.1mm), also clear of the margins and not associated with a definite nerve or lymphovascular space (2.7mm from right lateral margin and >5mm from the deep margin). This unusual finding was discussed in the gynaecology oncology multi-disciplinary team meeting and the consensus made for adjuvant radiation therapy based on the scant literature available.
Conclusions:
Vulval in-transit metastases are an extremely rare finding but based on literature available (mostly regarding SCC arising in other primary locations) they are associated with high rates of recurrence and poor prognosis. Clinical and pathological recognition of this rare entity is critical as adjuvant radiation is recommended in this setting and close follow up with biopsies of any suspicious lesions on any part of the body.