A 21-year-old woman is in the third trimester of an uncomplicated pregnancy. She has noted an enlarging nodule in her mouth for the past 2 weeks. On physical examination, there is a 1-cm red nodule on the left lateral gingiva below the first molar. The nodule regresses the following delivery. What is this nodule most likely to be?

A so-called pyogenic granuloma is described. Half of them are related to trauma and represent an exuberant repair reaction with granulation tissue. They can ulcerate and bleed. Bacillary angiomatosis represents a vascular proliferation that occurs in immunocompromised patients infected with Bartonella organisms. Cavernous lymphangiomas can be deforming mass lesions in the neck region of children, and though technically benign they do not have well-defined borders and can be difficult to excise. A glomus tumor typically presents as a painful nodule beneath the fingernail. There are various forms of Kaposi sarcoma (classic, endemic, AIDS-related) but they all appear as reddish-purple patches, plaques, or nodules on the skin and are associated with Kaposi sarcoma herpes virus (KSHV), also called human herpesvirus 8 (HHV8).