A rare case report: calcifying odontogenic cyst mimicking lateral periodontal cyst with 1-year Follow-up.

Background: Lateral periodontal cyst (LPC) and calcifying odontogenic cyst (COC) represent diagnostically challenging odontogenic lesions due to overlapping clinical and radiographic features. However, COC is exceptionally rare in periodontal tissues with only one case reported in the literature.

Case presentation: In this case, a 35-year-old male presented with an asymptomatic gingival swelling between teeth #22 and #23. Initial clinical examination revealed a 1.5 cm x 1 cm firm, translucent swelling with deep periodontal probing depths (PD) (14-15 mm). Radiographic evaluation demonstrated a well-circumscribed radiolucency between vital tooth roots, initially suggestive of LPC. However, histopathological analysis identified characteristic ghost cells and dystrophic calcifications, confirming a final diagnosis of COC. The lesion was managed with conservative enucleation and guided tissue regeneration, omitting peripheral ostectomy. At one year follow-up, complete osseous regeneration was observed with no evidence of recurrence. PD normalized to ≤ 3 mm, demonstrating successful periodontal restoration.

Conclusions: This case highlights three critical clinical insights: the necessity of histopathological confirmation for definitive diagnosis of radiographically ambiguous odontogenic cysts; the potential for conservative management in select COC cases without aggressive features; the importance of Cone-Beam Computed Tomography in evaluating cortical integrity and lesion extent. These findings contribute to evolving understanding of COC management paradigms, suggesting tailored surgical approaches may be appropriate based on lesion characteristics and radiographic findings. Long-term follow-up remains essential to validate treatment outcomes.