Cementoblastoma

§ overviewOverview

A benign odontogenic mesenchymal neoplasm characterised by proliferation of cementoblasts producing sheets of cementum-like tissue attached to the tooth root, with a peripheral radiolucent halo.

§ icdICD Classification

ICD-10 D16.5

§ etiologyEtiology

• 01Unknown; considered a true neoplasm arising from cementoblasts

§ riskRisk Factors

• 01Nil identified

§ geneticsGenetics & Molecular Biology

• 01No specific mutation identified

§ epidemiologyEpidemiology

< 1% of odontogenic tumours. 2nd–3rd decade. Slight male predilection. Mandibular first molar (~90%) most common.

§ pathogenesisPathogenesis

Neoplastic proliferation of cementoblasts synthesising sheets of mineralised cementum-like tissue continuous with the root cementum, causing root resorption/fusion.

§ clinicalClinical Features

• 01Slow-growing painful swelling (pain unusual in odontogenic tumours — a distinguishing feature)
• 02Associated tooth is vital
• 03Cortical expansion when large

§ signsSigns & Symptoms

• 01Vital, non-carious associated tooth
• 02Occasional trismus or paraesthesia when large

§ differentialDifferential Diagnosis

• 01Focal cemento-osseous dysplasia
• 02Osteoblastoma
• 03Hypercementosis
• 04Condensing osteitis
• 05Osteoma

§ criteriaDiagnostic Criteria

• 01Radiopaque mass fused to root with radiolucent halo
• 02Vital tooth
• 03Histology: sheets of cementum-like material with prominent cementoblastic rimming and reversal lines

§ histopathHistopathology

• 01Sheets and trabeculae of mineralised cementum-like tissue with prominent basophilic reversal lines
• 02Prominent cementoblasts rim the trabeculae
• 03Peripheral zone of unmineralised cementoid resembling osteoid seams
• 04Fibrous stroma; occasional multinucleated giant cells

§ radiographicRadiographic Features

• 01Well-defined round radiopaque mass fused to the tooth root
• 02Uniform radiolucent halo surrounding the mass (PDL-like)
• 03Root outline obscured/resorbed

§ opgOPG Findings

• 01Screening view; check tooth vitality

§ cbctCBCT Findings

• 01Assess extent, cortical integrity, IAN canal relation

§ ctCT Findings

• 01For very large lesions

§ mriMRI Findings

• 01Not indicated

§ investigationsInvestigations

• 01Vitality tests (must be vital)
• 02IOPA + OPG + CBCT
• 03Histology after excision

§ labsLaboratory Findings

• 01Non-specific

§ ihcIHC / Special Stains

• 01Osteocalcin positive; SATB2 positive; BSP (bone sialoprotein) positive

§ whoWHO Classification

WHO 2022: Benign odontogenic tumour of mesenchymal origin — Cementoblastoma.

§ classificationClassification

• 01Solitary lesion
• 02Multiple/gigantiform variant (extremely rare)

§ planTreatment Planning

• 01Extraction of tooth with attached tumour is standard as lesion is fused to root
• 02Root amputation with retention of remaining root and endodontic treatment attempted in select cases

§ treatmentTreatment

• 01Extraction of associated tooth with attached tumour + curettage of socket
• 02Selected small lesions — root amputation + endodontic therapy with preservation of tooth

§ medicalMedical Management

• 01Analgesics for pain

§ surgicalSurgical Management

• 01En-bloc tumour + tooth extraction with peripheral ostectomy
• 02Segmental resection reserved for very large aggressive lesions

§ reconstructionReconstruction Options

• 01Alveolar preservation graft after socket curettage; implant placement after healing

§ complicationsComplications

• 01Recurrence if incompletely removed
• 02Loss of adjacent teeth in aggressive lesions

§ recurrenceRecurrence Rate

Up to 22% if removed without associated tooth; < 5% after tooth + tumour extraction.

§ followupFollow-up Protocol

• 016 & 12 month post-op OPG then annually for 3 years

§ prognosisPrognosis

Excellent after complete removal.

§ preventionPrevention

• 01None applicable

§ examKey Examination Points

• 01Only true cementum neoplasm
• 02Painful odontogenic tumour
• 03Vital tooth
• 04Fused to root, radiolucent halo

§ revisionQuick Revision Summary

• 01Painful, mandibular first molar, vital tooth, fused to root, radiolucent halo, extract tooth + tumour

§ vivaBDS Viva Questions

• 01Define cementoblastoma.
• 02Why is it considered a true neoplasm?
• 03Radiographic hallmarks.
• 04Histology.
• 05Treatment.
• 06Recurrence rate.
• 07Differential from cemento-osseous dysplasia.
• 08IHC markers.
• 09Most common site.
• 10Sex predilection.

§ bdsBDS Professional Examination

• 01Short note: Cementoblastoma.
• 02Short note: Fibro-cemento-osseous lesions.

§ fcpsFCPS Residency Questions

• 01Discuss the classification and management of cemental lesions of the jaws.

§ pearlsClinical Pearls

• 01The only truly neoplastic cemental lesion; the rest are dysplasias.

§ mnemonicsMnemonics

• 014Fs = First molar, Fused to root, Fibrous halo, Fine pain

§ readingSuggested Reading

• 01Ulmansky M et al. Benign cementoblastoma: a review and five new cases. Oral Surg Oral Med Oral Pathol 1994.
• 02WHO 2022 blue book.

§ differentialDifferential Comparison

§ mcqsMCQs — Assessment (20)

§ relatedRelated Diseases

References

1. WHO Classification of Head and Neck Tumours, 5e (2022)
2. Neville BW. Oral and Maxillofacial Pathology, 4e
3. Shafer's Textbook of Oral Pathology, 9e