title: A heterosexual man with rash and rectal mass.
mesh_terms: D000328:Adult; D001005:Anus Neoplasms / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D010267:Parapsoriasis / Q000209:etiology*; D012007:Rectum / Q000473:pathology*; D013587:Syphilis / Q000150:complications / Q000175:diagnosis* / Q000473:pathology