Dear Editor, Vulval location: An indication for staging in basal cell carcinoma? Recently, DeAmbrosis et al. reported in the journal a case series of four vulval basal cell carcinoma (BCC). All the tumours were primary, and the maximum tumour size was 15 mm. The histopathological exam did not report invasion of deep structures, and none of the patients had previous history of radiation therapy. No clinical evidence of lymphadenopathy was reported at time of presentation. All patients underwent computed tomography (CT) of the abdomen and pelvis as a component of screening prior to surgery.1 The authors make several assertions that we disagree with. In the discussion, the authors recommend the use of this technique, as ‘CT scanning improves diagnosis accuracy’.1 In their opinion, ‘the risk of missing malignant inguinal lymphadenopathy is greater than the very marginal risk of the radiation from the CT scan’.1 We believe that in medical practice, before carrying out a particular technique, a careful benefit/risk analysis should be performed. A clear example is cutaneous malignant melanoma. Despite the marginal risk of the radiation from the CT scan, asymptomatic stage I melanoma patients should not be staged by imaging, as the true-positive pick-up rate is low and the false-positive rate is high.2 In other words, the benefit/risk relationship is unfavourable because the risk is low but the benefit is even lower. Although BCC is the most common skin cancer, metastatic BCC (MBCC) is rare, with an incidence of 0.0028–0.1%.1 Risk factors that should lead to a higher index of suspicion among clinicians for identifying MBCC include large tumour size, significant tumour depth, previous irradiation, recurrence, immunocompromised patients, and primary BCC of the head and neck.3, 4 Even though higher rates of metastasis occur from primary lesions on the face, scalp and genitalia, MBCC arising from a primary tumour less than 2 cm in diameter is extremely infrequent.4 Risk of metastasis has been further shown to specifically correlate with the size of the primary tumour: tumours greater than 3 cm conferring 2% risk, greater than 5 cm conferring 25% risk, and greater than 10 cm conferring 50% risk.3 Except for their location, none of the cases of DeAmbrosis et al. exhibit any of the recognizable risk factors for MBCC (with the exception of case 1, which presents squamous differentiation). Although we agree that vulval location is a risk factor for MBCC, we feel that CT scanning should not be performed in all cases of vulval BCC, as it should not be performed in all cases of facial BCC (albeit two-thirds of MBCC arise from primary tumours on the face4). We believe that ‘the very marginal risk of the radiation from the CT scan’ does not justify the routine staging use of this technique in asymptomatic patients unless it is supported by the presence of the risk factors recognized in the medical literature.