Metaplastic Ossification in Nasal Polyp

Bilateral multifocal inverted papilloma with osseous metaplasia of the sinonasal cavity

“… 4 However, in agreement with most reported cases of osseous metaplasia of the sinonasal region, our case had no history of sinonasal surgery. 1 , 2 , 3 , 4 , 5 Calcification of nasal polyps due to hypercalcemia have been reported, 4 but the serum calcium level of our case was normal. Hamartomas are tissue development errors and consist of abnormal mixture of focal tissues.…”

“…Metaplasia is the conversion of one type of tissue into a tissue different from its lineage. 1 Genetic reprogramming of epithelial stem cells or undifferentiated mesenchymal cells is thought to cause the metaplasia. 3 Metaplasia can occur in epithelial tissue or connective tissue.…”

“…The change from one cell type to another may be part of a normal maturation process or caused by an abnormal stimulus. 1 An inverted papilloma is a benign epithelial tumor composed of well-differentiated columnar or ciliated respiratory epithelium having variable squamous differentiation; it has a high recurrence rate and a squamous cell carcinoma association. Although bony metaplasia has frequently been described in polyps of the gastrointestinal tract, it is rarely encountered in the head and neck region.…”

“…Although bony metaplasia has frequently been described in polyps of the gastrointestinal tract, it is rarely encountered in the head and neck region. 1 , 2 In the head and neck region, lipomas are the most common lesions with osseous metaplasia; these are known as osteolipomas. 3 Osseous metaplasia is rarely encountered in nasal polyp cases and has not been reported in inverted papilloma.…”

Nasal Polyp With Heterotopic Bone Formation (Osseous Metaplasia): A Case Report

“…Nasal polyp is a common disease that usually present in 4% of the population, followed by chronic sinonasal infection and inflammatory condition [2]. OM is an unusual event that may occur anywhere but its presence in the nasal polyps is very rare, and has been reported in only eight cases in the English language literature [1,3]. In this report we present a rare case of OM in nasal polyp.…”