[Cystic parotid gland lesion evaluation].
OBJECTIVE
We evaluated differential diagnoses of cystic parotid gland lesions and the efficacy of preoperative diagnosis.


METHODS
Of 191 parotid gland nodules resected between January 2003 and October 2008, 167 (87%) were benign and 24 (13%) malignant. Thirty-five parotid gland nodules whose components were almost cystic were enrolled in this study. All cystic lesions were retrospectively evaluated with respect to preoperative diagnostic examinations and histopathological confirmed diagnosis. Cystic components in surgical specimens were also evaluated histopathologically. The relationships with magnetic resonance imaging (MRI) findings and histopathological confirmed diagnosis were studied.


RESULTS
Of 35 cystic lesions, 11 were complete cystic masses and had no mural nodules, while remaining 24 were incomplete and had mural nodules. Histopathological examinations showed that 5 were nonneoplastic, 27 were cystic degenerations of benign tumors, and 3 were cystic degenerations of malignant tumors. In the 11 complete cysts, preoperative diagnosis could not be made using any modality, whether with FNAC, salivary scintigraphy, or 67-gallium citrate scintigraphy. Of 24 incomplete cysts, only 9 cystic Warthin tumors were diagnosed correctly before surgery. Studies of cystic components in MRI and histopathology suggested that hemorrhagic degeneration of malignant tumors should be kept in mind for cystic lesions showing hemorrhagic portions.


CONCLUSIONS
Cystic parotid gland lesions are difficult to diagnose correctly before surgery, but the evaluation of cystic components by MRI and FNAC is helpful in differentiating between benign and malignant tumors.
Kikuchi
Masahiro
M
Department of Otolaryngology, Kobe City Medical Center General Hospital, Kobe.
Shinohara
Shogo
S
Fujiwara
Keizo
K
Hori
Shin-Ya
SY
Tona
Yosuke
Y
Yamazaki
Hiroshi
H
Kurihara
Risa
R
Kanazawa
Yuji
Y
Naito
Yasushi
Y
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003560:Cysts / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010305:Parotid Diseases / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies