Kimura disease: CT and MR imaging findings

Abstract

Background and purpose: KD is a rare chronic inflammatory disorder of unknown etiology. The purpose of this study was to evaluate the CT and MR imaging findings of KD in the head and neck.

Materials and methods: We retrospectively reviewed the CT (n = 21) and MR (n = 9) images obtained in 28 patients (24 males and 4 females; mean age, 32 years; age range, 10-62 years) with histologically proved KD in the head and neck.

Results: In these 28 patients, CT and MR images demonstrated a total of 52 non-nodal lesions, 1-8 cm in greatest diameter, in the head and neck. The lesions were unilateral in 11 patients and bilateral in 17 patients. Eleven patients had a solitary lesion, and 17 patients had 2-4 lesions. The parotid and/or periparotid area was the most frequent location, with 36 lesions in 23 patients. The margin of the lesions was well-defined in 1 and ill-defined in 51 cases. Compared with the adjacent muscle, the MR signal intensity of all lesions was iso- to slightly hyperintense on T1-weighted images and hyperintense on T2-weighted images. Most of the lesions demonstrated mild or moderate enhancement on postcontrast CT scans and moderate or marked enhancement on postcontrast MR images. MR images also showed tubular signal-intensity voids in 7 of 13 lesions. Associated lymphadenopathy was demonstrated in 23 patients, usually bilaterally.

Conclusions: Multiple ill-defined enhancing masses within and around the parotid gland with associated regional lymphadenopathy are characteristic CT and MR imaging findings of KD in the head and neck.

Fig 1.

KD involving bilateral parotid and periparotid areas in a 45-year-old man. A and B, Axial MR images show ill-defined soft-tissue masses in the bilateral retroauricular areas with infiltration of the adjacent parotid gland. Compared with the adjacent muscle, the lesions are isointense on the T1-weighted image (A) and hyperintense on the fat-suppressed T2-weighted image (B). C, Postcontrast fat-suppressed T1-weighted image shows homogeneous marked enhancement. Note multiple dotlike signal-intensity voids within the lesions, probably representing vascular structures (arrows in C). D, Photomicrograph shows attenuated lymphoid infiltrates rich in eosinophils surrounding numerous thin-walled vascular structures (hematoxylin-eosin, original magnification ×100).

Fig 2.

KD involving the postauricular area and occipital scalp in an 11-year-old boy. A, Postcontrast axial CT scan shows an ill-defined soft-tissue mass with homogeneous moderate enhancement involving the postauricular area on the right (arrow). Also note a smaller mass with the similar imaging characteristics on the right occipital scalp (arrowhead). B, Postcontrast axial CT scan shows multiple moderately enhancing and enlarged lymph nodes, right greater than left, on both sides of the neck.

Fig 3.

KD involving bilateral buccal spaces in a 52-year-old man. A, Axial T1-weighted MR image demonstrates ill-defined soft-tissue masses in the bilateral buccal spaces, isointense to the adjacent muscle. Note the reticular infiltration of the subcutaneous tissue around the lesions. B, Postcontrast coronal fat-suppressed T1-weighted MR image demonstrates homogeneous marked enhancement of the lesions. Note tubular or dotlike signal-intensity voids at the periphery of the lesions, probably representing fast-flowing vascular structures (arrows).

Fig 4.

KD involving bilateral lacrimal glands in a 13-year-old boy. A, Axial T1-weighted MR image shows diffuse enlargement of bilateral lacrimal glands (arrows). The signal intensity of the lesions is slightly hyperintense to the adjacent muscle. B, Postcontrast axial T1-weighted MR image shows homogeneous marked enhancement of the lesions (arrows).