Case002-Arrested Pneumatization of the Sphenoid Sinus – A Professional Teaching Case
Updated: 6 days ago
Clinical History
46-year-old female patient with the chief complaint of headache.
Imaging Findings
CT Findings (Paranasal Sinus):
Well-defined area in the sphenoid sinus.
Contains fat density foci and small punctate calcifications.
No aeration in this region; the rest of the sinus is patent.
No bone expansion, cortical thinning, or destruction.
MR Findings:
T1: Central iso- to mildly hyperintense, consistent with fat content.
T2: Central iso- to mildly hyperintense, with markedly hyperintense periphery (represents fibrous tissue or bone marrow interface).
Diagnosis: Arrested Pneumatization of the Sphenoid Sinus
Pathophysiology and Etiology
Arrested pneumatisation: A developmental variant characterized by residual fat tissue and calcifications due to incomplete or halted normal sinus pneumatization.
The sinus remains partially ossified and contains residual marrow fat (natural fat within the bone) along with calcifications.
It is a developmental anomaly; not inflammatory or neoplastic.
Important: These findings are mostly incidental, asymptomatic, and do not require treatment. Differentiating from fibrous dysplasia or neoplasms is crucial; misdiagnosis could lead to unnecessary surgery or follow-up.
Radiologic-Pathologic Correlation
CT fat density: Residual marrow fat within the incompletely pneumatized sinus.
Punctate calcifications: Represent physiological trabecular mineralization.
MR signal characteristics:
Central iso-/hyperintense on T1 and
T2 → fat marrow
Peripheral hyperintense on T1 and T2 → fibrous tissue or bone marrow interface
No aeration: Typical for arrested pneumatisation.
🎯 Summary – Key Differential Points
Bone expansion + ground-glass appearance = Fibrous dysplasia
Dense sclerotic mass = Osteoma
Fibrous + mixed mineralized density = Ossifying fibroma
Sinusitis findings + opacification + bone erosion = Fungal sinusitis
Fat + calcification + non-expansile = Arrested Pneumotization
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