Paediatric parotid neoplasms: a 10 year retrospective imaging and pathology review of these rare tumours

Parotid rhabdomyosarcoma with spindle cell features masquerading as a benign salivary gland tumour: Pitfall alert

Rhabdomyosarcoma (RMS) is the most common sarcoma in children and adolescents, with the head and neck region, extremities, and genitourinary tract being the most common locations. Rhabdomyosarcoma of the salivary glands is rarely seen in children and can easily be mistaken for their benign counterparts. We report a case of rhabdomyosarcoma in the parotid region that clinically and cytologically masqueraded as a benign parotid gland tumour, leading to diagnostic difficulties. However, the excised specimen revealed histomorphological and immunophenotypic features consistent with rhabdomyosarcoma. The child underwent a total parotidectomy followed by chemotherapy and is doing well without recurrence. Although cytology is minimally invasive and has good specificity, there are rare cases, such as this one, where histopathology provided the definitive diagnosis. This report aims to raise awareness of RMS of the parotid gland among clinicians, cytopathologists, and radiologists, aiding in the early diagnosis and treatment of these cases.

Differentiation malignant from benign parotid tumors in children with diffusion-weighted MR imaging

PURPOSE

To differentiate pediatric solid malignant from the benign parotid tumors with diffusion-weighted MR imaging (DWI).

MATERIALS AND METHODS

A retrospective study comprising 38 children with parotid tumors (21 boys and 17 girls aged from 2 months to 17 years) was conducted using (DWI) of the parotid gland. Apparent diffusion coefficient (ADC) maps were generated. The ADC value of the parotid tumors was calculated.

RESULTS

The mean ADC value of malignant parotid tumors (1.08 ± 0.1, 1.04 ± 0.1 × 10^-3mm²/s) was significantly lower [P = 0.001] than that of benign lesions (1.69 ± 0.2, 1.72 ± 0.3 × 10^-3mm²/s). A threshold of ADC of 1.40, 1.33 × 10^-3mm²/s was used for differentiating malignant parotid tumors from benign lesions and led to the best results of the area under the curve of 0.940, 0.929, accuracy of 86, 89%, sensitivity of 94, 94%, specificity of 80, 85%, negative predictive value of 94.1, 94.4%, and positive predictive value of 81, 85%. There was insignificant difference in ADC values of malignant lesions (P = 0.23, 0.30) as well as within benign lesions (P = 0.25, 0.08).

CONCLUSION

DWI is an innovative anticipating imaging technique that can be used in the differentiation of pediatric solid malignant parotid tumors from benign lesions.

Fine-Needle Aspiration Cytology Is an Effective Diagnostic Tool in Paediatric Patients with Mucoepidermoid Carcinoma as Secondary Neoplasm

BACKGROUND

Mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland tumour in paediatric population, accounting for 16% of all cases. Patients affected by a previous solid or leukaemic neoplasm during their childhood may develop a second different tumour during the follow-up. In this setting, salivary gland MEC is relatively frequent, accounting for 6% of the second neoplasms in paediatric patients. Consequently, the occurrence of salivary gland nodules in paediatric patients with a previous neoplasm should be considered an event with a high risk of malignancy that poses peculiar diagnostic challenges.

SUMMARY

This study was designed to define clinical and instrumental findings and morphological features of MEC on fine-needle aspiration cytology (FNAC) samples in paediatric patients with and without a previous neoplasm. Five patients under 19 years are included in this series. FNAC was performed in all patients on a parotid nodule. We have identified 2 groups of patients: (a) 2 cases with previous history of malignancy (acute lymphoblastic leukaemia and Hodgkin lymphoma) and (b) 3 cases without previous malignant neoplasms. In all cases, a final diagnosis of MEC was rendered. Key Messages: MEC may occur as a second malignancy in paediatric patients. FNAC is certainly a valid and accurate diagnostic tool for this type of neoplasm, even in the paediatric age, allowing the correct management of the patients.

Pediatric salivary gland carcinomas: Diagnostic and therapeutic management

OBJECTIVES/HYPOTHESIS

To analyze clinical presentations, treatment modalities, and evolution of pediatric cases of salivary gland carcinomas to standardize care for these rare diseases.

STUDY DESIGN

Multicentric, retrospective study.

METHODS

We included in this retrospective study all children and adolescents (aged ≤18 years) treated from 1992 to 2012 in six pediatric centers in Paris, France. Pathological tumor specimens of these cases were reviewed.

RESULTS

Forty-three children were included (sex ratio male/female = 19/24, median age = 13 years). The parotid gland was the most common (37 cases) location for tumors. Histological subtypes were mucoepidermoid carcinomas (n = 20), acinic cell carcinomas (n = 14), and other (n = 9). Initial fine-needle aspiration was performed in 15 cases (33%), and was concordant to final diagnosis in three cases (20%). Primary surgery was performed in 42 patients, leading to a complete microscopic resection in 80%. Associated lymph node dissection was performed in 28 patients (homolateral: 27, bilateral: 1) and showed lymph node metastases in only two patients. One patient had distant metastases. Adjuvant irradiation was delivered to 11 patients (median: 60 Gy; range: 50-65) and chemotherapy in five cases. After a median follow-up of 5 years, six tumors relapsed, but no deaths occurred.

CONCLUSIONS

Childhood salivary gland carcinomas have a good prognosis despite possible recurrences. Treatment is mainly based on surgery, with simultaneous node dissection in cases of clinical or radiologic node enlargement. Radiation therapy seems to be restricted to inoperable high-grade tumors or after recurrence.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:140-147, 2017.