Oliveira Alves et al. Journal of Medical Case Reports 2011, 5:406 http://www.jmedicalcasereports.com/content/5/1/406 formation of the ulcer. At the beginning of the healing stage, proliferation of the overlying epithelium is observed, which is demonstrated microscopically by pseudoepitheliomatous hyperplasia. If infarction is lim- ited, no sequestration occurs. Healing becomes evident by the phagocytic activity of histiocytes and neutrophils and the presence of granulation tissue [2,3]. In the pre- sent case, the biopsy was obtained at an early stage of the disease, a fact that may explain the absence of an ulcer. Squamous metaplasia of the ductal epithelium, accom- panied by pseudoepitheliomatous hyperplasia of the overlying epithelium, might be confused with squamous cell carcinoma [2] when viewed under the microscope, despite the presence of a minimum number of mitoses, pleomorphism, and hyperchromatism [3]. In the present case, the process was detected at the very early stage of the disease that is characterized by the absence of nodular ulcerated lesion. The ulcer that developed 14 days after biopsy showed spontaneous remission 30 days after its occurrence and involution of the nodule was observed. Necrotizing sialometaplasia resolves spontaneously and the lesion heals by secondary intention within four to ten weeks. Therefore, no treatment is necessary [2,3,10]. Once the lesion has healed, recurrence or func- tional impairment is not observed [8]. A biopsy is neces- sary when the clinical findings indicate other diagnostic hypotheses [2], as observed in the present case. Conclusion In conclusion, histopathological examination is neces- sary in cases of necrotizing sialometaplasia since the clinical features of this condition can mimic other dis- eases, particularly salivary gland tumors. Consent Written informed consent was obtained from the patient for publication of this case report and any accompany- ing images. A copy of the written consent is available for review by the Editor-in-Chief of this journal. Authors’ contributions MGOA was a major contributor in writing the manuscript. YRC performed the histological examination. JDA, DK and LAGC analyzed and interpreted the patient data, performed the surgical procedures, and took the photographs. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 25 April 2011 Accepted: 23 August 2011 Published: 23 August 2011 Page 3 of 3 References 1. Fava M, Cherubini K, Yurgel L, Salum F, Figueiredo MA: Necrotizing sialometaplasia of the palate in a cocaine-using patient. A case report. Minerva Stomatol 2008, 57:199-202. 2. Imbery TA, Edwards PA: Necrotising sialometaplasia: literature review and case reports. JADA 1996, 127:1087-1092. 3. Keogh PV, O’Regan E, Toner M, Flint S: Necrotizing sialometaplasia: an unusual bilateral presentation associated with antecedent anaesthesia and lack of response to intralesional steroids. Case report and review of the literature. Br Dent J 2004, 196:79-81. 4. Rizkalla H, Toner M: Necrotizing sialometaplasia versus invasive carcinoma of the head and neck: the use of myoepithelial markers and keratin subtypes as an adjunct to diagnosis. Histopathology 2007, 51:184-189. 5. Sandmeier D, Bouzourene H: Necrotizing sialometaplasia: a potential diagnostic pitfall. Histopathology 2002, 40:200-201. 6. Solomon LW, Merzianu M, Sullivan M, Rigual NR: Necrotizing sialometaplasia associated with bulimia: case report and literature review. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007, 103:e39-42. 7. Abrams AM, Melrose RJ, Howell FV: Necrotizing sialometaplasia: A disease simulating malignancy. Cancer 1973, 32:130. 8. Ylikontiola L, Siponen M, Salo T, Sándor GK: Sialometaplasia of the soft palate in a 2-year-old girl. J Can Dent Assoc 2007, 73:333-336. 9. Anneroth G, Hansen LS: Necrotizing sialometaplasia: the relationship of its pathogenesis to its clinical characteristics. Int J Oral Surg 1982, 11:283-291. 10. Lee DJ, Ahn HK, Koh ES, Rho YS, Chu HR: Necrotizing sialometaplasia accompanied by adenoid cystic carcinoma on the soft palate. Clin Exp Otorhinolaryngol 2009, 2:48-51. doi:10.1186/1752-1947-5-406 Cite this article as: Oliveira Alves et al.: Necrotizing sialometaplasia as a cause of a non-ulcerated nodule in the hard palate: a case report. Journal of Medical Case Reports 2011 5:406. Submit your next manuscript to BioMed Central and take full advantage of: • Convenient online submission • Thorough peer review • No space constraints or color ﬁgure charges • Immediate publication on acceptance • Inclusion in PubMed, CAS, Scopus and Google Scholar • Research which is freely available for redistribution Submit your manuscript at www.biomedcentral.com/submit