Case #1:

Clinical Presentation:
A 35 year old HIV+ man with AIDS complains of a painful oral lesion

Case 1 Image 1 shows: an erythematous, punched-out ulcer on the buccal mucosa with an overlying necrotic membrane. On examination, the lesion is exquisitely tender and friable. There is a foul odor.

Clinical Diagnoses:
Herpes simplex
Apthous ulcer
Fungal ulcer: histoplasmosis, cryptococcosis
Cytomegalovirus
Syphilis

Microscopic examination of lesion scrapings:
(Case 1 Image 2) Gram stain: gram-negative, spindle-shaped bacilli admixed with enormous numbers of gram-negative spiral forms characteristic of Borrellia species (Case 1 Image 3) Giemsa stain: spindle shaped bacilli, superimposed onto a lawn of spiral forms

Discussion:
Microbiologic Diagnosis:
Oral Fusospirochetosis
Diagnosis of oral lesions in the setting of HIV can be aided by microscopic examination of Gram and Giemsa stained smears of lesion scrapings. Fusospirochetosis is an overgrowth of normal anaerobic oral flora, often secondary to an underlying primary lesion (eg viral ulcers).