Module 07

Differential Diagnosis Tables

Head-to-head comparison tables by presentation. For finding-based filtering, use the interactive Differential tool.

20 tables

Adenomatoid Odontogenic Tumour

Odontogenic Tumors

Entity	Shared feature	Distinguisher
Dentigerous cyst	Radiolucency at CEJ	AOT extends apically beyond CEJ, shows flecks of calcification
CEOT	Driven snow	Middle-aged, posterior mandible, Liesegang rings
COC	Ghost cells + calcifications	Histology diagnostic

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Aneurysmal Bone Cyst

Non-odontogenic Cysts

Entity	Shared feature	Distinguisher
Solitary bone cyst	Empty cavity, scalloping	No cortical ballooning; adolescent
CGCG	Multilocular anterior mandible	Same histology (giant cells) — but no USP6 fusion, no fluid–fluid levels
Telangiectatic osteosarcoma	Malignant fluid–fluid levels	Cellular atypia, malignant osteoid; older patients
Ameloblastoma	Soap-bubble, expansile	Epithelial neoplasm; no blood-filled cavities

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Cementoblastoma

Odontogenic Tumors

Entity	Shared feature	Distinguisher
Hypercementosis	Widening of PDL preserved	No radiolucent halo; no root resorption
Cemento-osseous dysplasia	Multiple, apical, middle-aged Black female	Not fused to root; teeth vital; usually no expansion
Osteoblastoma	Bone matrix, not fused to root	Histology + radiographic relation
Condensing osteitis	Non-vital tooth, no expansion	Vitality of tooth

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Erythematous (Atrophic) Candidiasis

Red Lesions

Entity	Shared feature	Distinguisher
Erythroplakia	Red patch	Does not respond to antifungals; biopsy shows dysplasia
Denture allergy	Red palate under denture	Onset with new denture material; patch test positive
B12 deficiency glossitis	Red smooth tongue	Low B12, macrocytic anaemia

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Erythroplakia

Red Lesions

Entity	Shared feature	Distinguisher
Erythematous candidiasis	Red patch	Responds to antifungals; KOH positive
Atrophic lichen planus	Red areas with striae	Bilateral symmetrical, Wickham striae
Contact stomatitis	Red	History of allergen contact; resolves on removal
Early SCC	Red with induration	Induration, ulcer, invasive histology

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Geographic Tongue

Red Lesions

Entity	Shared feature	Distinguisher
Erythematous candidiasis	Red patch on tongue	KOH positive; static distribution; responds to antifungals
Nutritional glossitis	Smooth red tongue	Uniformly bald; low haematinics
Reiter's oral lesion	Geographic-like lesion	Arthritis, conjunctivitis, urethritis triad

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Lateral Periodontal Cyst

Odontogenic Cysts

Entity	Shared feature	Distinguisher
Lateral radicular cyst	Non-vital tooth	Vitality testing
OKC (lateral variant)	Larger, more aggressive	Parakeratin, higher recurrence
Botryoid odontogenic cyst	Multilocular grape-like	Higher recurrence than LPC

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Leukoedema

White Lesions

Entity	Shared feature	Distinguisher
White sponge nevus	Bilateral spongy folds	Does NOT disappear on stretching; onset in childhood
Leukoplakia	White plaque	Unilateral, focal, does not disappear on stretch
Cheek biting	Shredded white surface	Along occlusal line, history of parafunction

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Leukoplakia

White Lesions

Entity	Shared feature	Distinguisher
Frictional keratosis	Trauma-related	Resolves in 2–4 weeks after removing irritant
Lichen planus	Reticular Wickham striae	Bilateral symmetrical, band-like lymphocytic infiltrate
Candidiasis (pseudomembranous)	White curdy plaque	Wipes off, KOH shows hyphae
White sponge nevus	Bilateral spongy folds since childhood	Autosomal dominant, keratin 4/13 mutation

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Median Rhomboid Glossitis

Red Lesions

Entity	Shared feature	Distinguisher
Erythroplakia	Red velvety patch	Does not respond to antifungals; dysplasia on biopsy
Geographic tongue	Red patches with white borders	Migrating, multiple, benign
Granular cell tumour	Firm submucosal nodule	S100 positive on biopsy

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Nasolabial Cyst

Non-odontogenic Cysts

Entity	Shared feature	Distinguisher
Radicular cyst	Bony radiolucency at root apex	Non-vital tooth; visible on radiograph
Nasopalatine cyst	Midline anterior maxilla	Intra-osseous, heart-shaped radiolucency
Salivary gland tumour of lip	Firm nodule in labial mucosa	Different location; solid on imaging
Dermoid cyst	Midline or lateral, contains skin appendages	Histology: keratin, hair follicles

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Nasopalatine Duct Cyst

Non-odontogenic Cysts

Entity	Shared feature	Distinguisher
Radicular cyst	Root apex radiolucency	Non-vital tooth; not midline
Large incisive foramen	< 6 mm, no expansion, no symptoms	Normal anatomy; watchful waiting
Nasolabial cyst	Soft-tissue swelling of upper lip/ala	Extra-osseous; no radiographic radiolucency
OKC	Aggressive, scalloped	Parakeratinised lining; posterior mandible more common

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Odontogenic Keratocyst

Odontogenic Cysts

Entity	Shared feature	Distinguisher
Dentigerous cyst	Attached CEJ, unilocular	Buccolingual expansion; parakeratin absent; recurrence rare
Ameloblastoma	Multilocular soap-bubble	Marked buccolingual expansion; ameloblast-like palisading; BRAF V600E
Aspirate	Thick cheesy/dirty white	Protein < 4 g/dL (vs > 5 in radicular cyst)

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Odontogenic Myxoma

Odontogenic Tumors

Entity	Shared feature	Distinguisher
Ameloblastoma	Soap-bubble	Ameloblast-like palisading; BRAF V600E; different histology
CGCG	Multilocular anterior mandible	Multinucleated giant cells; often crosses midline
Central haemangioma	Multilocular	Aspiration → blood; life-threatening bleed

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Odontoma

Odontogenic Tumors

Entity	Shared feature	Distinguisher
Ameloblastic fibro-odontoma	Radiopacity + soft-tissue component	Younger age; ameloblast-like epithelium histology
CEOT (Pindborg)	Driven snow / scattered radiopacities	Liesegang rings, amyloid histology
Osteoma	Dense uniform bone	No enamel/dentin components

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Oral Candidiasis

White Lesions

Entity	Shared feature	Distinguisher
Leukoplakia	White plaque	Cannot be wiped off
Chemical burn	White slough	History of caustic contact; wipes off with bleeding
Milk residue	White in infant mouth	Wipes off with no erythema; no hyphae on KOH

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Oral Lichen Planus

White Lesions

Entity	Shared feature	Distinguisher
Lichenoid drug reaction	Unilateral, asymmetric	Temporal relation to drug; resolves on withdrawal
Discoid lupus	Central atrophy with radiating striae	Positive ANA, direct IF shows granular IgG at BMZ
Leukoplakia	Unilateral homogeneous plaque	No striae, no bilateral symmetry
MMP	Desquamative gingivitis	Nikolsky positive, sub-epithelial split, linear IgG/C3 at BMZ

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Radicular Cyst

Odontogenic Cysts

Entity	Shared feature	Distinguisher
Periapical granuloma	< 1 cm, ill-defined	Histology required; cannot distinguish reliably on radiograph
Dentigerous cyst	Surrounds crown of unerupted tooth	Attached at CEJ, associated tooth is vital
Nasopalatine cyst	Heart-shaped, midline	Between vital central incisors
COD (early)	Multiple periapical radiolucencies	Associated teeth are vital; middle-aged Black females

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Solitary Bone Cyst

Non-odontogenic Cysts

Entity	Shared feature	Distinguisher
OKC	Scalloped, aggressive	Epithelial lining with parakeratin on histology
Central giant cell granuloma	Multilocular expansile	Multinucleated giant cells; often anterior mandible
Stafne cavity	Well-defined lucency below IAN canal	Depression of lingual cortex containing salivary tissue — no true cavity
Aneurysmal bone cyst	Rapidly expanding, multilocular	Blood-filled spaces; younger patients

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White Sponge Nevus

White Lesions

Entity	Shared feature	Distinguisher
Leukoedema	Bilateral milky	Disappears on stretching; adult onset; ethnic
HBID	Spongy plaques + conjunctival plaques	Haliwa–Saponi Native American heritage; eye involvement
Pachyonychia congenita	Oral leukokeratosis + palmoplantar keratoderma + nail changes	KRT6/16/17 mutations; systemic features

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