Aim To report a case of a non-neoplastic variant of calcifying odontogenic cyst (COC) with the lining epithelium showing ameloblastomatous proliferation and capsule exhibiting features of a cholesterol granuloma. The importance of delineating this histologic variant from unicystic ameloblastoma and the formation of cholesterol granuloma in this variant is discussed. Background Calcifying odontogenic cyst is a developmental jaw cyst, which presents itself as both the neoplastic and the non-neoplastic forms. The ameloblastomatous variant of COC is often mistaken for unicystic ameloblastoma and treated aggressively. Case report A 68-year-old female who presented with a cystic enlargement of the posterior mandible on the right side was suggestive of unicystic ameloblastoma based on radiography and initial biopsy report. Microscopic examination of the excision specimen, however, was fitting in favor of calcifying odontogenic cyst with ameloblastomatous proliferation. Conclusion Identifying the non-neoplastic ameloblastomatous variant of COC from a cystic ameloblastoma is crucial as the treatment of the two lesions vary considerably. Clinical significance This case emphasizes the need for thorough examination of the entire surgical specimen before arriving at an appropriate diagnosis. How to cite this article Aparna M, Gupta M, Sujir N, Kamath A, Solomon M, Pai K, Radhakrishnan R. Calcifying Odontogenic Cyst: A Rare Report of a Nonneoplastic Variant associated with Cholesterol Granuloma. J Contemp Dent Pract 2013;14(6):1178- 1182.

A 4-month-old infant was referred by a paediatrician for a rapidly growing swelling on the right side of the mandible of 1.5 months duration. His medical and family history was unremarkable. Palpation divulged a firm and tender enlargement with the overlying soft tissue showing no significant alteration in colour. CT scan revealed cortical irregularity involving the ramus on the right side along with right masseter muscle hypertrophy. Routine haematological investigation yielded values within normal limits except for a raised erythrocyte sedimentation rate. Histopathological examination of the tissue submitted following an open biopsy procedure showed reactive lamellar bone and trabeculae with fibrous marrow exhibiting inflammation. The final diagnosis of infantile cortical hyperostosis was clinched based on the clinicopathological correlation. A rare reactive bone dystrophy which could pose a certain diagnostic dilemma is addressed herewith.