Mucoepidermoid carcinoma presenting as a retromolar mucocele
A 44-year-old female presented with painless intraoral swelling in left retromolar area since 2 years. This swelling was gradually increasing in size with time. Clinical examination revealed a 2 cm smooth, spherical swelling at left retromolar region, which was normothermic, non-tender, soft in consistency, fluctuant, fluid-filled, bluish in color with stretched mucous membrane []. Regional lymph nodes were not palpable.\nUltrasound examination showed a thick walled cystic space occupying lesion in the floor of mouth in left submandibular region. Blood examination revealed hemoglobin 12.2 gm/dl, chest X-ray was normal. Ultrasound-guided fine needle aspiration was done using 18 G needle, which revealed hazy, straw color fluid. Aspirate was sent for fluid analysis, which revealed amorphous nature of fluid without presence of cells. After aspiration size of swelling reduced significantly. Blood picture was non contributory to any systemic pathology. Preoperative clinical diagnosis of retention cyst of salivary gland was made. Surgical excision was planned but unfortunately patient did not turn up for next appointment as swelling was reduced after aspiration.\nAfter 2 years patient again visited with the same complaint of intraoral swelling since 3 months. Size of swelling was increased significantly to 4 cm extending from left retromolar region to left maxillary tuberosity. CT scan revealed hypodense non-enhancing lesion medial to left mandibular angle. The imaging gave a conclusion remark of possibilities such as mucocele, lymphangioma, or necrotic lymph node [Figures and ].\nClinical diagnosis of mucocele was made and surgical excision was planned via submandibular approach. Under general anesthesia left submandibular incision was given. Blunt dissection was done to expose left submandibular gland. Care was taken to preserve marginal mandibular nerve. Cystic sac was identified on medial aspect of angle of mandible. Blunt dissection was performed to gently free sac from adjacent soft tissue attachments. Cystic sac was excised [], with care taken to prevent any damage to cyst wall. Intraoral examination was done to check for complete enucleation. Hemostasis was achieved and closure was done in layers. Specimen was marked and sent for histopathological examination.\nPatient was discharged after 3 days of observation. Follow-up revealed uneventful healing without any major complications or recurrence. A follow-up of 15 months was uneventful.\nThe histopathology picture showed a large macrocystic area lined by the dysplastic epithelial cells. The connective tissue capsule was thick with a variety of patterns presented by the dysplastic epithelial cells. Large sheets with syncytial arrangement of cells, small nests and islands, single strands of cells forming India file and reticular pattern. The connective tissue showed a dense lymphocytic response with formation of germinal centers. Very few microcysts were seen. The unique feature histopathologically is that the tumor showed all types of cell differentiation: epidermoid, squamous, intermediate, mucus, clear, and columnar cells forming variety of epithelial patterns [Figures and ].