Diagnostic Information

History of Present Illness A 36-year-old female physician presents to your office for a new patient examination. The patient is asymptomatic but noticed a “bump on the roof of my mouth” several months ago. She denies local trauma and all teeth in the area are asymptomatic and demonstrate normal vitality testing. A periapical radiograph of the affected area is within normal limits. Medical History - Adverse drug effects: none

- Medications: none

- Pertinent medical history: seasonal allergies

- Pertinent family history: paternal - alive and healthy, maternal - breast cancer survivor; no siblings

- Social history: denies tobacco, alcohol, and recreational drug use; patient is a marathon runner Clinical Findings Extraoral examination is within normal limits. Intraoral examination reveals a well-defined, 1.5 x.1.5 cm smooth surfaced mass on the right side of the posterior hard palate, just anterior to the vibrating line (Figure 1). The overlying surface mucosa is intact. An incisional biopsy is performed and the tissue submitted for histopathologic examination.

Figure 1. Smooth surfaced mass on the right posterior hard palate just anterior to the vibrating line.

Histopathologic Findings The incisional biopsy shows a circumscribed partially encapsulated glandular neoplasm composed of ductal epithelial cells, myoepithelial cells, and mesenchymal stromal elements. The myoepithelial cells display a plasmacytoid morphology with pink cytoplasm. The stroma consists of fibrohyaline to loose myxoid fibrous connective tissue with areas of cartilaginous matrix. No marked cytologic pleomorphism, mitotic activity, necrosis, or infiltrative growth are identified.

Figure 2. Low-power histologic image showing a circumscribed partially encapsulated glandular neoplasm composed of epithelial cells, myoepithelial cells, and stromal elements including fibromyxoid connective tissue and adipose tissue.

Figure 3. High-power histologic image showing ducts lined by epithelial cells with surrounding sheets of plasmacytoid myoepithelial cells and myxoid to pink hyaline stroma.

Figure 4. High-power histologic image with islands of plasmacytoid epithelial cells and myxoid to chondroid stromal elements.