Intraorbital granular cell tumor: MR findings

Imaging findings of granular cell tumours of the head and neck

AIM

To review the imaging characteristics of granular cell tumours in the head and neck and assess their associations with pathological findings.

MATERIALS AND METHODS

Eleven patients (10 [91%] women, mean age 43 years) with histopathologically confirmed granular cell tumours were included in this study. Preoperative imaging studies were performed, including computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound. The location of the tumours, their imaging features, and histopathological findings were analysed.

RESULTS

Among the 11 granular cell tumours, four (36%), three (27%), and two (18%) tumours were found in the submucosal layer, subcutaneous layer, and intramuscular area, respectively. On CT, all tumours exhibited homogeneous iso-attenuating enhancement compared with adjacent muscle, and nine out of the 11 tumours (81%) demonstrated well-defined margins. On T2-weighted imaging (T2WI), four out of five tumours (80%) demonstrated iso-signal intensity compared with adjacent muscles, and four tumours (80%) exhibited homogeneous signal intensity. The apparent diffusion coefficient (ADC) values ranged from 0.68-0.81 × 10-3 mm2/s. Histopathological examination revealed densely packed tumour cells with variable amounts of fibrous stroma.

CONCLUSION

Granular cell tumours were characterised by well-defined and iso-signals on T2WI and low mean ADC values, and were predominantly located in the submucosal, subcutaneous, or intramuscular areas in middle-aged women. The characteristic locations, demographic characteristics, and imaging findings can help to differentiate granular cell tumours from other soft-tissue tumours in the head and neck.

Progressive orbital granular cell tumour associated with medial rectus

Granular cell tumour is a rare soft tissue tumour that can occur in any part of the body, but seldom in ocular adnexa. It usually behaves in a benign fashion. We report a case of a 54-year-old man with a well-demarcated, solitary, slow-growing orbital tumour which lead to significant ocular symptoms. The case was a diagnostic and therapeutic challenge due to its location and difficulty in obtaining tissue for a histological diagnosis. Surgical biopsy attempts were made but they all failed to uncover the true identity of the lesion. A definitive diagnosis was revealed with complete surgical excision of the tumour, which was challenging due to its size and close association with rectus muscle. This case has highlighted that orbital granular cell tumour may result in significant ocular symptoms. Adequate exposure to the anatomical site is the key to obtaining diagnosis and complete excision of a lesion.