Oliveira Alves et al. Journal of Medical Case Reports 2011, 5:406 http://www.jmedicalcasereports.com/content/5/1/406 C A S E R E P O R T JOURNAL OF MEDICAL CASE REPORTS Open Access Necrotizing sialometaplasia as a cause of a non- ulcerated nodule in the hard palate: a case report Mônica Ghislaine Oliveira Alves, Dárcio Kitakawa, Yasmin Rodarte Carvalho, Luiz Antonio Guimarães Cabral and Janete Dias Almeida* Abstract Introduction: Necrotizing sialometaplasia is a benign, self-limiting and rare inflammatory disease which, on clinical and histological examination, mimics malignant neoplasms. Case report: We report the case of a healthy 25-year-old Caucasian woman with a three-week history of a painless lump on her hard palate. Oral examination revealed a nodule consisting of two lobules on the right side that measured 2.5 cm. Her mucosa was normal in color and a fluctuant area was detected in the posterior region upon palpation. Our patient was submitted to incisional biopsy and histopathological examination. The histological diagnosis was necrotizing sialometaplasia. The lesion had healed spontaneously after 30 days, with observed signs of involution of the nodule. Conclusion: Histopathological examination is necessary for the diagnosis of necrotizing sialometaplasia because the clinical features of this condition can mimic other diseases, particularly malignant neoplasms. Introduction Necrotizing sialometaplasia is a benign, self-limiting and rare inflammatory disease of the minor salivary glands [1-6], which was first described as a distinct entity by Abrams et al. in 1973 [7]. Knowledge about the disease is required because it mimics malignant neoplasms on clinical and histological examination, particularly squa- mous cell carcinoma and mucoepidermoid carcinoma [2-4,6,8]. We report the clinical and histopathological features of a case of necrotizing sialometaplasia present- ing initially without ulceration in a young adult woman. Case report A healthy 25-year-old Caucasian woman was seen at our stomatology outpatient clinic with a three-week history of a lump on her hard palate, which was non-tender upon oral examination. Our patient reported the pre- sence of a stabbing pain radiating to the region of the temporomandibular joint in the previous week. The patient was a dentist and made a self-diagnosis of an abscess. * Correspondence: janete@fosjc.unesp.br Department of Biosciences and Oral Diagnosis, São José dos Campos Dental School, Universidade Estadual Paulista - UNESP, São José dos Campos, São Paulo, Brazil Clinical examination revealed a submucosal nodule on the right side of her hard palate that measured almost 2.5 cm in its major diameter. The color of the mucosal surface was normal (Figure 1A) and a fluctuant area was detected in the posterior region upon palpation. Occlu- sal radiography revealed no abnormalities (Figure 1B). The first diagnostic hypothesis was malignant salivary gland tumor; most likely mucoepidermoid carcinoma considering the stabbing pain, duration of the lesion and palpation of a fluctuant area. An incisional biopsy was performed. Histological examination of the specimen revealed a mucosal fragment lined with parakeratinized stratified epithelium exhibiting mild hyperplasia. Several minor salivary gland lobules were found deep in the lamina propria, which were characterized by atrophic, sometimes broken acini, leakage of mucus, intraglandu- lar ductal dilatation, and a moderate stromal mononuc- lear inflammatory infiltrate. Some lobules were necrotic, although the lobular architecture was preserved. The lobules were permeated by ducts with squamous meta- plasia. Leakage of eosinophilic amorphous material was observed, which was intermingled with an intense mixed inflammatory infiltrate containing foamy macrophages. No signs of malignancy were found. The diagnosis was necrotizing sialometaplasia (Figure 2). © 2011 Oliveira Alves et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.