CT Report

History

A 30-year-old female patient presents with a three-month history of swelling on the left side of the face, complaints of swelling in the floor of the left nasal cavity, giddiness for two months, pain on the left upper tooth, and a recent episode of bleeding from the nose.

Technique

Contrast-enhanced CT study of the paranasal sinuses was performed.

Findings

Lesion Characteristics

• A hypodense lytic lesion measuring 1.9 x 2.1 x 1.4 cm is seen in the left pyramidal location in the anterior aspect of the maxilla.
• The lesion shows a plain CT value of 39 to 45 HU.
• The margins are well-circumscribed laterally with significant thinning and mild cortical break in the anterior aspect.
• The lesion involves the central incisors of the left side and partly of the right side, extending to the root region of the second tooth from the midline on the left side and partly to the root of the third tooth from the left side.
• A tooth measuring 8.7 x 4 mm is embedded within the cystic area, separate from the other roots.

Extension and Enhancement

• The lesion bulges into the left nasal cavity, extending posteriorly for a length of 95 mm, and causes mild mucosal thickening.
• No breach in the inferior wall of the cyst is observed.
• Post-contrast images show minimal enhancement of the cyst wall with no enhancing components within the lesion.

Additional Findings

• Minimal mucosal thickening is noted in the right maxillary sinus, bilateral anterior and right posterior sinuses, left frontal sinus, and right sinus without air-fluid levels.
• Conchobullosa is observed in the right middle turbinate with mucosal thickening.

Impression and Recommendation

Based on the imaging findings and clinical history, the differential diagnosis is categorized as follows:

Single Most Likely Diagnosis

• Odontogenic Keratocyst (OKC): The presence of a tooth within the cystic lesion, the location in the maxilla, and the characteristics of the lesion (hypodense, lytic, and well-circumscribed with cortical thinning) are consistent with an OKC, now more commonly referred to as a Keratocystic Odontogenic Tumor (KCOT).

Other Likely Diagnoses

• Dentigerous Cyst: Given the association with an unerupted tooth and the location, a dentigerous cyst is a plausible diagnosis, although the presence of a tooth within the cyst and the specific characteristics might lean more towards an OKC/KCOT.
• Radicular Cyst: This is a common odontogenic cyst that could present similarly, especially if associated with a non-vital tooth. However, the presence of a tooth within the cyst and the specific location and characteristics might make this less likely.

Do Not Miss Diagnoses

• Ameloblastoma: Although less likely given the clinical presentation and imaging characteristics, ameloblastoma is an important diagnosis not to miss due to its potential for aggressive behavior and the need for appropriate management.

Rare Diagnoses

• Calcifying Epithelial Odontogenic Tumor (CEOT): This is a rare odontogenic tumor that could present as a cystic lesion in the jaw, but it typically has distinctive calcifications within the lesion, which were not described in this case.
• Glandular Odontogenic Cyst: A rare jaw cyst that could present similarly, but it often has a more aggressive behavior and specific histological features that would require biopsy for diagnosis.

Given the clinical presentation and imaging findings, the most likely diagnosis is an Odontogenic Keratocyst (OKC), now referred to as a Keratocystic Odontogenic Tumor (KCOT). Further evaluation, including biopsy and histopathological examination, is recommended to confirm the diagnosis and guide appropriate management.