Space occupying lesions of parotid gland. Comparative diagnostic imaging and pathological analysis of echo color/power Doppler and of magnetic resonance imaging

Abstract

Aim of the study was to evaluate the role of echo color/power Doppler and magnetic resonance imaging in the diagnosis of space occupying parotid lesions, in the attempt to establish criteria for differential diagnosis between benign and malignant types. The study population comprised 49 patients (23 male, 26 female), age range 30-85 years, with a space occupying lesion of the parotid gland. Each lesion was carefully studied with ultrasound integrated with colour/power doppler and magnetic resonance imaging; patients were then submitted to echo-guided needle-biopsy and surgical excision. A preliminary evaluation by means of ultrasound revealed the site, size of lesion, echostructure and borders. Echo colour/power Doppler and magnetic resonance imaging can play a very important role both in diagnosis and pre-operative surgical planning of parotid lesions, although cost and availability, the former to be recommended vs. magnetic resonance imaging, which is poorly accessible, expensive, and not always accepted by the patients.

Fig. 1

A) Echo Color Doppler: Longitudinal scan. Pleomorphic adenoma with prevalent periphery vascularization with few central spots. TYPE 1. B) Cystic lesion with hypervascularized septum (Color Doppler). TYPE 2. This finding is indicative of Warthin’s cystoadenolymphoma. C) Hypoechogen neoplasm with intralesion vascularization (Echo Doppler). TYPE 2. Non Hodgkin Lymphoma. D) Hypoechogen lesion with total parotid alteration (Echo Color Doppler): spread vascularization. TYPE 3-4. Unidifferentiated carcinoma.

Fig. 2

A) SE T1 sequence weighted. Coronal scan. Bilateral hypointense lesion localized in the right superficial parotid. Pleomorphic adenoma in the left deep parotid. B) FSE T2 sequence weighted. Axial scan. Evident hyperintensity of neoplasm in the right superficial parotid. Pleomorphic adenoma in the left deep part. C) SE T2 sequence weighted. Axial scans. Hypointense lesion weight irregular margins infiltrating adipose subcutaneous tissue. Masseter muscle relationship is poorly defined. Undifferentiated carcinoma. D) FSE T2 sequence weighted. Hyperintense lesion with non-homogenous features due to the presence of small necrotic areas. The muscle appears to be hyperintense with a suspicious infiltration. Undifferentiated carcinoma.