Table 2.

Results of the imaging study of occult neoplasm patients

Patient	Imaging study	Time to 1st image	1st image at other hospital	No of imaging before diagnosis	Initial imaging finding	Time interval to follow up image	Interval progression	Reason for diagnostic delay
1 Skin SCC	MR Head	13	no	2	FN enhancement	9	More prominent FN enhancement	Nonspecific FN enhancement
2 Parotid ACC	MR Head	5	yes	1	Normal (report only, other hospital)	N/A*	N/A	Normal in initial MR
3 Skin SCC	MR Head	14	yes	2	Normal	6	Multiple cranial nerve enhancement	Normal in initial MR
4 Parotid ACC	MR Head	5	yes	2	FN enhancement	11	More prominent FN enhancement	Nonspecific FN enhancement
5 Skin SCC	MR Head	3	yes	2	Normal (report only, other hospital)	24	Multiple cranial nerve enhancement	Unknown
6 Skin SCC	MR Head	6	yes	2	Normal (report only, other hospital)	7	abnormal enhancement in FN and parotid gland	Unknown
7 Facial nerve schwannoma	MR Head	4	yes	2	Normal (report only, other hospital)	2	Facial nerve focal tumor	Unknown
8 Facial nerve schwannoma	MR Head	6	yes	2	Normal (report only, other hospital)	174	Facial nerve focal tumor	Unknown
9 Parotid malignancy	MR Head	5	yes	3	Normal (report only, other hospital)	12	Parotid tumor with multiple neck metastasis	Misdiagnosis†

No number; FN facial nerve; SCC squamous cell carcinoma; ACC adenoid cystic carcinoma

^*The occult tumor was identified at exploration surgery without follow-up MR

^†Although the formal radiologic reports of the initial MR image from the radiologist at the outside hospital were compatible with Bell’s palsy, our neuroradiologist re-evaluated the initial MR image and found a small suspicious lesion in the parotid deep lobe