Final answer:
The bump on the external genitalia described as a cauliflower-like mass is likely genital warts, which are caused by certain strains of the human papillomavirus (HPV).
Step-by-step explanation:
A person who has observed a small cauliflower-like mass on their external genitalia that has grown over a few weeks, which is not particularly painful and has no other symptoms, is likely experiencing genital warts. Genital warts are small, rough growths caused by an infection with certain strains of the human papillomavirus (HPV). They are a commonly seen sexually transmitted infection, and while they are not usually painful, they can be a cause for concern due to the association of HPV with other health issues, such as cervical cancer. It is important for anyone with symptoms of genital warts to consult a healthcare professional for diagnosis and treatment.