Asymptomatic “Bump” on Dorsal Tongue

History of Present Illness

Rajish is a 33- year-old software engineer who recently immigrated to the United States. He presents to your office for evaluation of a “bump” on his tongue. He first noticed the lesion approximately 8 months ago and relates some sensitivity when eating spicy foods. Otherwise, the lesion is asymptomatic. His last visit to a dentist was 2 years ago in India.

Medical History

  • Adverse drug effects: sulfa drugs (erythema multiforme reaction associated with prior Septra exposure)
  • Medications: naproxen as needed for shoulder soreness
  • Pertinent medical history: osteoarthritis, prior BCG vaccination (recently completed a 9 month regimen of prophylactic Isoniazid)
  • Pertinent family history: paternal - fatal MI age 65 (long-term smoker), maternal - DM type 2 managed with diet. Siblings are healthy.
  • Social history: denies tobacco or alcohol exposure and denies recreational drug exposure

Clinical Findings

Extraoral examination reveals normal TMJ function, no facial muscle tenderness, and no cervical lymphadenopathy. Intraoral examination reveals a well-defined, elliptical, pink-colored plaque (~4 cm x 5 cm) on the left anterior-dorsal aspect of the tongue. The central aspect of the lesion exhibits a ring of erythema with a small, shallow, linear-shaped ulceration (Figure 1). There is no induration or discomfort noted on palpation. The remaining oral mucosal tissues are within normal limits. An incisional biopsy is performed and the tissue submitted for histopathologic examination.

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Figure 1. Pink-colored plaque on the left anterior-dorsal tongue.

Histopathologic Findings

The tongue biopsy shows an inflamed mucosal soft tissue fragment consisting of stratified squamous surface epithelium with underlying fibrovascular connective tissue and skeletal muscle. The superficial interface inflammatory infiltrate consists predominantly of small lymphocytes and histiocytes. The reactive surface epithelium displays hyperplasia with elongated ragged rete ridges, basal dissolution, lymphocytic exocytosis, scattered necrotic keratinocytes, basement membrane thickening, and hyperkeratosis (Figures 3-4). Direct immunofluorescence (DIF) shows shaggy basement membrane zone fibrin deposition. IgG, IgA, IgM, and C3 stains are negative.

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Figure 2. Low power histologic image of a mucosal soft tissue fragment exhibiting an interface chronic inflammatory infiltrate. The stratified squamous surface epithelium is hyperplastic and hyperkeratotic.

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Figure 3. High power histologic image showing the interface lymphocytic infiltrate with basal epithelial dissolution, lymphocytic exocytosis, and focal necrotic epithelial cells.