Peripheral primitive neuroectodermal tumor of the parotid gland region: report of a case with fine-needle aspiration findings

Primary Ewing sarcoma of the liver: Diagnosis, management, and prognosis: A case report and literature review

Ewing's sarcoma tumors (ES) are a rare entity exceptionally localized on the liver. We report a case of an ES of the liver in a 26-year-old man who presented with abdominal pain. The diagnosis was confirmed with a histopathological examination of the left hepatectomy specimen and adjuvant chemotherapy was received.

Peripheral facial palsy, the only presentation of a primitive neuroectodermal tumor of the skull base

•

A 2-month-old male infant presenting with only peripheral facial palsy was diagnosed with a primitive neuroectodermal tumor of the skull base.

•

Primitive neuroectodermal tumors located in the skull base are rarely detected in infants.

•

After subtotal resection of the tumor, asymmetrical facial expression showed mild improvement.

Introduction

Peripheral facial palsy is rarely caused by primary neoplasms, which are mostly constituted of tumors of the central nervous system, head and neck, and leukemia.

Presentation of case

A 2-month-old male infant presented with asymmetric facial expression for 3 weeks. Physical examination revealed suspicious findings of right peripheral facial palsy. Computed tomography of the temporal bone revealed a suspicious bone tumor centered in the right petrous bone involving surrounding bones with extension into the middle ear cavity and inner ear. Subtotal resection of the tumor was performed due to crucial structures adjacent the mass. Histopathology and immunohistochemistry of the resected tumor was consistent with primitive neuroectodermal tumor.

Conclusion

We report a rare case of a primitive neuroectodermal tumor located at the skull base presenting with only peripheral facial palsy.

Peripheral primitive neuroectodermal tumor of the parotid gland in a child: A case report

Primitive neuroectodermal tumor (PNET) is a term used to describe a group of highly malignant neoplasms of soft-tissue origin, with varying degrees of divergent differentiation. The occurrence of peripheral PNET in the head and neck region has been reported infrequently in the medical literature. This disease generally occurs in adolescents and young adults, and rarely occurs in children <3 years old. The current study presents an extremely rare case of pPNET of the parotid gland in a 2-year-old male, which had been previously misdiagnosed and treated as a mumps. The lesion showed the characteristic histological features of pleomorphic cellular infiltrate with hyperchromatic small cells scattered in the fibrovascular stroma, interposed by fibrous septa and Homer-Wright rosettes. Positive immunohistochemical staining for CD99 and vimentin was detected. The patient was treated with chemotherapy and radiotherapy following surgical removal, and has been under close observation since the treatment (approximately seven months), with no signs of recurrence. The clinical history and radiological and histopathological findings are presented, together with the immunoreactivity of this tumor.

Mouth metastasis of peripheral primitive neuroectodermal tumor

We describe a case of oral metastasis of peripheral primitive neuroectodermal tumor (pPNET) in a 68-year-old man, who presented the primary lesion in the chest. Oral metastasis of pPNETs is very rare and we have not found any similar case reported in the English literature. Clinical examination showed an extensive and ulcerated fleshy mass measuring 3.0 x 3.5 cm in the right lower gingivae. Microscopic examination showed sheets of proliferating small, hyperchromatic, round cells. Tumor cells were reactive to neuron-specific enolase (NSE), vimentin and MIC-2 gene by immunohistochemistry, consistent with PNET. The patient died 3 weeks later because of respiratory insufficiency.

MR imaging of salivary glands

Diagnostic imaging of salivary glands has been revolutionized with the advent of cross-sectional imaging modalities like CT and MR imaging. In the era before CT, imaging of the salivary glands was relatively unrewarding and was used uncommonly by ear-nose-throat surgeons. Early diagnostic tests like plain films and sialography evaluated dilated parotid ducts and calculus disease within ducts or glands. Full evaluation of salivary glands, especially deep lobes of parotid gland and masses of minor salivary glands, was not possible by these methods, however. Imaging of the parotid glands has developed significantly since that time. CT and MR imaging greatly compliment physical and endoscopic examinations (and previous favorites like sialography) by direct visualization of previously blind areas of the salivary glands and extension of the disease process in surrounding tissue planes.

Malignant peripheral primitive neuroectodermal tumor-peripheral neuroepithelioma of the head and neck: a clinicopathologic study of five cases and review of the literature

BACKGROUND

The term primitive neuroectodermal tumor (PNET) encompasses a number of neoplasms of common neuroectodermal origin, but of variable clinical, histopathologic, ultrastructural, and molecular characteristics. Here, we focus on one particular member of the PNET family, the malignant peripheral PNET (pPNET) or peripheral neuroepithelioma of head and neck.

METHODS

Five patients diagnosed with malignant pPNET-peripheral neuroepithelioma of head and neck were included in the study. All existing literature was reviewed.

RESULTS

The diagnosis of malignant pPNET-peripheral neuroepithelioma of the head and neck was confirmed in all five cases. All patients are alive after treatment with a combination of therapeutic modalities; only one patient had metastatic disease develop. A literature review revealed another 38 reported cases.

CONCLUSIONS

Malignant pPNET-peripheral neuroepithelioma should be included in the differential diagnosis of small, round, blue cell tumors of head and neck. A combination of multiple diagnostic modalities is essential for correct diagnosis, and multimodality treatment offers the best outcome.

MR imaging of salivary glands

In conclusion, if a parotid gland mass is bilateral, it is more likely to be Warthin's tumor, especially if it does not enhance. Less likely, it could be lymphoepithelial cyst or necrotic lymph node. A unilateral, non-enhancing mass with a high T2 signal is more likely to be a Warthin's tumor and less likely a necrotic lymph node or first branchial cleft cyst. If the mass is unilateral, shows postcontrast enhancement, has a high T2 signal, and does not invade surrounding tissue planes, it is more likely to be a pleomorphic adenoma. An intermediate to low T2 signal mass-with or without invasion of surrounding tissue planes--is more likely to be a malignant mass such as adenocystic or mucoepidermoid carcinoma. Biopsy is superior and the gold standard for diagnosis and cannot be replaced by MR imaging, however.

Primitive neuroectodermal tumour of the mandible

Primitive neuroectodermal tumors (PNETs) are relatively rare tumors. Tumors that once would have been diagnosed as Ewing's sarcoma are now often designated as peripheral neuroepithelioma or synonymously PNET. Herein we report the first case of PNET of the mandible in a 6-year-old female who was admitted to the hospital with a two-months history of painless, progressively enlarging lower jaw mass.