Tender cutaneous nodules of the legs: diagnosis and clinical clues to diagnosis.

BACKGROUND: "Tender cutaneous nodules of the legs" is a common manifestation in dermatology. Histopathological investigation is usually required for this condition, because clinical data are frequently insufficient to make a definite diagnosis. OBJECTIVE: To identify and analyze the causes of patients presenting with tender leg nodules and to reveal clinical clues that could help to differentiate causes. MATERIALS AND METHODS: The medical records and histopathological slides of patients presenting with tender cutaneous nodules of the legs between January 2005 and December 2007 were retrospectively reviewed. RESULTS: Of the total of 154 patients, 122 (79.2%) were female. Definite diagnoses were categorized into four groups: inflammation (84.4%); infection (5.8%); tumor (6.5%); and nonspecific (3.2%). The most common cause in the inflammation group was erythema nodosum. The infections found were Acremonium spp., Penicillium sp., Mycobacterium abscessus, Mycobacterium fortuitum and Mycobacterium leprae. The tumors included leiomyoma, leukemia cutis, and lymphomas. Clinical data that correlated with and could be used as clues for the inflammation group were female sex (P = 0.03, OR 6.43) and lower leg involvement (P = 0.03, OR 7.14). LIMITATIONS: The retrospective manner of this study is a limitation. CONCLUSION: Various inflammatory conditions, infections, and tumors can present as tender cutaneous nodules of the legs. Female sex and lower leg involvement were clinical data that could be used as clues for the diagnoses in the inflammation group. However, histopathological investigation is still crucial to determine a definite diagnosis in patients presenting with tender cutaneous nodules of the legs.