Chikara Saito

Merkel cell carcinoma of palatal mucosa in a young adult: Immunohistochemical and ultrastructural features

The first case report of a merkel cell carcinoma arising from the palatal mucosa in a young adult is presented. The histopathological similarities of this tumour in skin and oral mucosa are also discussed. The patient was a 14-year-old female with a non-symptomatic painful swelling in the left molar region of the maxilla. Under the diagnosis of a malignant tumour, a partial maxillary resection was performed, but there was a recurrence, and finally the patient died of cerebral metastasis. The tumor was composed mainly of uniform small cells. Immunohistologically, a large number of the cells were reactive to neuron specific enolase (NSE) and cytokeratin CK19, and some of the cells were positive to CK8, CK13, CK20, PGP9.5 and CEA focally and slightly. Pseudo-rosette formation and squamous differentiation were frequently detected. The ultrastructure of the tumour cells showed abundant Golgi bodies associated with neurosecretory granules. We conclude that it is the first case of a Merkel cell tumour arising from palatal mucosa and invading underlying bone with reactive hyperplasia. These findings closely resemble those of the same tumour occurring in the skin

Nodular fascitis of the mandible in a child.

Nodular fascitis is an unusual, tumor-like, proliferative, fibroblastic lesion with infiltrative properties. We describe a case of nodular fascitis appearing in the mandible of a 2-year-old boy. A brief review of the literature on this lesion arising from intra or perioral regions, and the importance of differential diagnosis for this lesions are discussed.

Morphologic Evaluation for Safe Le Fort I Osteotomy in Cleft Lip and Palate

Objective: The present study aimed to determine the structure and morphology of the maxilla in patients with cleft lip and palate to ensure safe Le Fort I osteotomy. Patients: A total of 34 sides of 17 patients with unilateral cleft lip and palate (nonsyndromic cases) were included in this study. The control group included 10 sides of 5 patients who exhibited skeletal mandibular protrusion without malformation. Methods: Finite element analysis was performed to examine the distribution of occlusal force over the maxilla, and continuous 3-dimensional measurement was performed at the sites of stress concentration. Results: In patients with cleft lip and palate, bones at the lateral border of the piriform aperture and the anterior wall of the maxillary sinus were significantly thicker than those in controls (P < .05). Furthermore, the attachment of the pterygomaxillary junction was wider and thicker (P < .05), and the anterior distance to the descending palatine artery was shorter (P < .01) in patients with cleft lip and palate than in controls. Our results further indicated that alveolar bone grafting may significantly influence bone thickness and the attachment state of the pterygomaxillary junction. Conclusions: Our results suggest that the complications of LFI can be reduced in patients with cleft lip and palate by ensuring proper understanding of each patient’s maxillary anatomy and bone thickness, as well as the location of the descending palatine artery and the attachment state of the pterygomaxillary junction.