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Sinonasal Inverted Papilloma Showing a Misleading Finding on Magnetic Resonance Imaging
Yuki Numano1, Kazuhiro Nomura1, Mitsuru Sugawara1
1Department of Otolaryngology, Tohoku Kosai Hospital, Sendai-shi, Miyagi, Japan.
Abstract:
Sinonasal inverted papilloma (IP) is the most common benign tumor in sinonasal cavities. Treatment involves excising the whole tumor, so it is essential to evaluate the extent of the tumor by preoperative radiographic findings. Magnetic resonance imaging (MRI) is superior to computed tomography (CT) for determining a tumor's location as MRI can discern the difference between mucus and IP. We herein report a 51-year-old man with sinonasal IP treated with endoscopic sinus surgery (ESS). Preoperative MRI showed findings resembling a convoluted cerebriform pattern on T2-weighted imaging, but this site was not enhanced by intravenous gadolinium at all. We preoperatively suspected that this site was not part of the tumor but rather the accumulation of mucus, and indeed, we found no tumor at this site when we performed the surgery. This patient is a valuable example of misleading findings of IP on T2-weighted imaging and underscores the importance of contrast-enhanced T1-weighted imaging to determine the extent of IP.
Insights
Sinonasal inverted papilloma (IP) can present misleading T2-weighted MRI findings. Contrast-enhanced T1-weighted imaging is crucial for accurately determining the extent of sinonasal inverted papilloma before surgery.
Area of Science:
- Otolaryngology
- Radiology
- Oncology
Background:
- Sinonasal inverted papilloma (IP) is the most common benign tumor in sinonasal cavities.
- Accurate preoperative assessment of tumor extent is vital for complete surgical excision.
Purpose of the Study:
- To highlight the diagnostic challenges of sinonasal inverted papilloma using MRI.
- To emphasize the importance of contrast-enhanced MRI sequences for surgical planning.
Main Methods:
- Case report of a 51-year-old male patient with sinonasal inverted papilloma.
- Preoperative Magnetic Resonance Imaging (MRI) including T2-weighted and contrast-enhanced T1-weighted sequences.
- Surgical treatment via Endoscopic Sinus Surgery (ESS).
Main Results:
- T2-weighted MRI showed a convoluted cerebriform pattern, initially suggestive of tumor extension.
- This specific area did not enhance with intravenous gadolinium, indicating it was not tumor.
- Intraoperative findings confirmed the absence of tumor at the non-enhancing site, identifying it as mucus accumulation.
Conclusions:
- T2-weighted imaging alone can provide misleading information regarding the extent of sinonasal inverted papilloma.
- Contrast-enhanced T1-weighted MRI is essential for differentiating tumor from non-tumoral content like mucus.
- Accurate preoperative staging using contrast-enhanced MRI improves surgical outcomes for sinonasal inverted papilloma.
