Rare paraneoplastic erythroderma associated with ectopic neuron-specific enolase deposition in basal cells

The cutaneous symptom of the paraneoplastic erythroderma can be the only symptom of a malignancy. Although many cases associated with malignancies have been reported, the pathogenesis of cancer related erythroderma is still unclear. Herein we presented a patient with large cell neuroendocrine carcinoma (LCNEC) of the lung and contemporary severe erythroderma. The patient suffered from skin erythema and scaling all over the body and the cutaneous lesions recovered completely after 3 weeks of surgery. Strong expression of neuron-specific enolase (NSE, 2+ positive) was found in both primary cancer and basal cells of the preoperative skin. Three months later, postoperative skin biopsy presented nearly normal skin tissues, accompanied with a negative expression of NSE. Nine months after surgery, cancer recurred in the liver and brain with the first symptom of skin erythema and scaling. The pathology of liver biopsy tissues illustrated the LCNEC and 3+ positive expression of NSE. The skin biopsy tissues showed 2+ positive stain of NSE. Evaluation after two cycles of chemotherapy showed marked improvement in erythroderma and reduction of tumor volume. However, the patient experienced recurrent worsening of erythroderma when chemotherapy was terminated due to severe myelosuppression. Eleven months after surgery, the patient died of cancer cachexia and multiple organ failure. To our knowledge, this was the first case of paraneoplastic erythroderma associated with LCNEC of lung. Furthermore, we firstly discovered that the deposition of NSE in basal cells might be a crucial pathogenic factor of erythroderma.