Abstract
An 87-year-old woman developed warm, painful, and poorly demarcated erythema on both lower legs. The combination of these clinical manifestations, a slightly elevated serum C-reactive protein level, and leukocytosis led to a tentative diagnosis of cellulitis. However, the administration of antibiotics did not improve her symptoms. A histopathological analysis of a skin specimen taken from the erythematous lesion on her left leg revealed septal panniculitis and so we diagnosed the patient with erythema nodosum. Bed rest did not improve the patient’s symptoms, and her serum C-reactive protein levels continued to increase. A computed tomography scan revealed thickening of the gastric wall together with adenopathy of the perigastric and periaortic lymph nodes, and a gastric ulcer was found during endoscopy. A histopathological analysis of a biopsy specimen taken from the ulcer revealed diffuse large B-cell lymphoma. The final diagnosis in this case was erythema nodosum accompanied with Malignant Lymphoma. The possibility of a dermadrome involving an underlying malignancy should be considered in patients with persistent or refractory erythema nodosum, especially in elderly patients.
