Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 52 7 2014 07 15 578 581 Vitorino Modesto dos Santos Catholic University Medical Course, Brasília-DF, Brazil. AND Department of Internal Medicine, Armed Forces Hospital, Brasília-DF, Brazil. Thiago Pereira Loures Department of Internal Medicine, Armed Forces Hospital, Brasília-DF, Brazil. João Daniel Bringel Rego Division of Pneumology, Armed Forces Hospital, Brasília-DF, Brazil. Christiane Aires Teixeira Division of Pneumology, Armed Forces Hospital, Brasília-DF, Brazil. Kayursula Dantas de Carvalho Department of Internal Medicine, Armed Forces Hospital, Brasília-DF, Brazil. Afonso Lucas Oliveira Nascimento Department of Internal Medicine, Armed Forces Hospital, Brasília-DF, Brazil. 2015 10 11 Pachyonychia congenital (PC) is a rare autosomal dominant genodermatosis characterized hyperkeratosis affecting the nails and palmoplantar areas, oral leukokeratosis, and cystic lesions. A 39-year-old woman with PC type 1 (Jadassohn-Lewandowsky syndrome) and B-cell lymphoma is described. No similar disorders or parental consanguinity were found in her family. Typical features of PC developed since her early childhood and the diagnosis of B-cell lymphoma was established seven years ago, without a clear causal relation between these entities. Despite inherent limitations of a single case, this report may contribute to PC understanding. https://acta.tums.ac.ir/index.php/acta/article/view/4571 https://acta.tums.ac.ir/index.php/acta/article/download/4571/4520