A case of BPOP and osteochondroma

A 17-year-old female noticed a hard sublingual mass 3 months prior and experienced stiffness during yawning. The oral mucosa then became ulcerated, and a calcified mass was exposed with whitish and partially bluish color. On computed tomography, the mass was ovoid and lobulated with irregular calcification and measured about 30 × 20 mm on the lingual area of the right mandibular body. The calcified mass showed no continuity with the cortical bone of the mandible on X-ray (Fig. 1A); therefore, it was enucleated through simple intraoral dissection at Seoul National University Dental Hospital. The removed specimen was submitted to the Department of Oral Pathology, Gangneung-Wonju National University Dental Hospital (GWNUDH) for analysis. It was composed of cartilaginous and osseous tissues on gross observation. The cartilaginous tissue was approximated to the lingual surface of the mandibular body, while the osseous tissue had grown toward the sublingual area (Fig. 2A). The lesion was diagnosed as BPOP through pathological examination (OS2014-25).

Radiographic views of this study. A Computed tomography of BPOP, an irregularly calcified mass located on the lingual side of the mandibular body without cortical attachment (arrows). A1 Frontal plane. A2 Horizontal plane. B Panoramic view of osteochondroma, enlarged left condylar head (arrows)

BPOP. A1 Sublingual ulceration with a whitish calcified mass. A2 Removed mass showing partial bluish color (arrows). A3 BPOP specimen was composed of cartilaginous (1) and osseous (2) tissue. A4 Bizarre chondrocytes (arrows) in cartilaginous tissue. B HE stain. B1–B3 (area 1 of A3). B4, B5 (area 2 of A3). B1 and B3 show core cartilage covered with thick perichondral fibrous tissue. B4 and B5 show anastomosing trabecular bone centered from cartilaginous tissue, mimicking endochondral ossification. C–G IHC stains with no background stain. C PCNA. D BMP-2. E BMP-4. F RUNX2. G OC

A 39-year-old female presented with severe malocclusion and facial asymmetry, which had slowly progressed for 4 years. She was referred to GWNUDH with a chief complaint of slight pain on the left temporomandibular joint during mouth opening. Her left mandibular condyle was severely enlarged with cortico-medullary continuity from adjacent bone structures on orthopantomogram (Fig. 1B). The tumorous condyle was surgically removed by high condylectomy and diagnosed as osteochondroma through pathological examination (S2014-4).