RESUMEN
OBJECTIVE: To investigate the impact of a preoperative CT on surgical decision making in primary vulvar squamous cell carcinoma (VSCC) and the accuracy of detecting inguinal lymph node metastases (LNM). Secondly to assess prevalence and consequences of incidental findings and comorbidity using a CT. METHODS: This population-based study comprised of surgically treated patients with primary VSCC, at a regional tertiary center, using the Swedish Quality Registry for Gynecological Cancer for identification, and medical records were reviewed. Results from the preoperative CT was compared with the histological analysis from the lymphadenectomy in the total cohort and between tumor size <4 cm versus ≥4 cm. RESULTS: In total 134 women had undergone CT before sentinel node (SN) biopsy (n = 83) or inguinofemoral lymphadenectomy (IFL) (n = 51). Fiftyone patients (38%) had groin LNM. Accuracy of CT in detecting groin LNM was 76%; sensitivity 43% and specificity 96%. Positive (PPV) and negative predictive values (NPV) were 88% and 73% respectively. In tumors <4 cm (n = 87), sensitivity, specificity, PPV and NPV were 17%, 95%, 57% and 75% and in tumors ≥4 cm (n = 47) 67%, 100%, 100% and 69% respectively. CT altered surgical method from SN biopsy to IFL in only two cases. Incidental findings led to extra follow-up resulting in a benign diagnosis in 22 patients and major important findings in five patients. CONCLUSION: In primary VSCC, a preoperative abdominal-inguinal CT is of limited value for surgical decision making. In tumors <4 cm, it may be omitted due to low diagnostic accuracy and disturbing incidental findings.