ABSTRACT
The clinical characteristics and pathogenesis of acral melanoma of the foot (AMF) have not been sufficiently elucidated. Clinical or subclinical persistent inflammation of the feet is caused by dermatophytosis of the feet (DPF). Persistent inflammation is potentially associated with oncogenesis. Moreover, diabetes has been reported to be associated with the development of dermatophytosis and cancer. The present study aimed to elucidate the clinical association between DPF and AMF, with consideration of diabetes. The medical records of 114 Japanese patients were retrospectively examined and divided into an AMF group (n = 30) and a control group consisting of patients with foot diseases other than melanoma (n = 84). Microscopic DPF screening was performed on all patients who reported symptoms in the foot, with or without AMF. Patients underwent a microscopic test to detect the presence of dermatophytes, and the diagnosis of DPF was made based on a positive result. In the AMF group, 18 (60.0%) and eight (26.7%) patients had DPF and diabetes, respectively. Four patients (13.3%) had both DPF and diabetes. In the control group, 25 (29.8%) and 11 (13.1%) patients had DPF and diabetes, respectively. Five patients (6.0%) had both DPF and diabetes. Univariate analyses showed a significantly higher prevalence of DPF in the AMF group than in the control group (odds ratio, 3.540; p = 0.003, Pearson χ2 test). Furthermore, multivariate analyses of sex, body mass index, DPF, and diabetes revealed DPF as a significant factor associated with AMF (odds ratio, 4.285; p = 0.002, logistic regression analysis). The hyperkeratotic type of DPF was more frequently observed in patients with AMF than in control patients (odds ratio, 11.083; p < 0.001, Pearson χ2 test). In conclusion, the present study found a significantly higher prevalence of DPF, especially its hyperkeratotic type, in patients with AMF. DPF may be associated with AMF pathogenesis.
ABSTRACT
Cancer-associated hypercalcemia commonly occurs through abnormal secretions of parathyroid hormone-related protein (PTHrP) from cancer cells. Several cases of PTHrP-producing melanoma causing hypercalcemia have been reported; however, effective management of PTHrP-producing BRAF wild-type melanoma causing hypercalcemia after immune checkpoint inhibitor (ICI) failure is unclear. We report a case of PTHrP-producing BRAF wild-type melanoma leading to oncological emergency by hypercalcemia that was successfully treated with dacarbazine after ICI failure. A 65-year-old Japanese woman had advanced BRAF wild-type melanoma that was refractory to ICI, and then led to hypoxia through exacerbated lung metastases and pleural effusion. Moreover, hypercalcemia appeared in parallel with increase of the serum PTHrP level. Dacarbazine was administered, and after the first administration, the pleural effusion was gradually decreased and hypoxia rapidly disappeared, and the serum calcium and PTHrP levels were improved within normal limits. Dacarbazine after ICI failure is potentially a useful option for oncological emergency due to progression of BRAF wild-type melanoma including PTHrP-producing types. Dacarbazine should be reevaluated as a therapeutic option for oncological emergency in patients with BRAF wild-type melanoma after ICI failure.
