Malignant peripheral nerve sheath tumours

Nasal Cavity and Paranasal Sinuses

The nasal cavity and paranasal sinuses occupy the top of the upper respiratory tract and form pneumatic spaces connected with the atmosphere. They are located immediately beneath the base of the cranium, where crucial vital structures are harbored. From this region, very much exposed to airborne agents, arise some of the more complex and rare benign and malignant lesions seen in humans, whose difficulties in interpretation make this remarkable territory one of the most challenging in the practice of surgical pathology.

Contents of this chapter cover inflammations and infections, polyps and pseudotumors, fungal and midfacial destructive granulomatous lesions, as well as benign, borderline, and malignant neoplasms. Among the neoplasms, emphasis is made on those entities characteristic or even unique for the sinonasal region, such as Schneiderian papillomas, glomangiopericytoma, intestinal- and non-intestinal-type adenocarcinomas, olfactory neuroblastoma, nasal-type NK-/T-cell lymphoma, and teratocarcinosarcoma. Moreover, recently recognized entities involving this territory, i.e., HPV-related non-keratinizing carcinoma, NUT carcinoma, and SMARCB1-deficient basaloid carcinoma, are also discussed in the light of their specific molecular findings. Furthermore, the text is accompanied by numerous classical and recent references, several tables, and 100 illustrations.

Malignant peripheral nerve sheath tumors of the head and neck: Demographics, clinicopathologic features, management, and treatment outcomes

OBJECTIVES

To determine the epidemiology and prognostic indicators in patients with malignant peripheral nerve sheath tumors (MPNST) of the head and neck.

MATERIALS AND METHODS

The surveillance, epidemiology, and end results registry was reviewed for patients with head and neck MPNST from 1973 to 2011. Study variables included age, sex, race, tumor size, stage at presentation, and treatment modality.

RESULTS

There were 374 cases of head and neck MPNST identified. Mean age at diagnosis was 50.7 y ears; 60.2% of patients were male and 82.6% were white. After diagnosis, 38.8% of patients underwent surgery and radiation therapy and 48.1% underwent surgery alone. Kaplan-Meier analysis demonstrated overall (OS) and disease-specific survival (DSS) of 51% and 67% at 5 years. Multivariate Cox regression analysis showed that age (p=0.030), stage (p=0.002), surgery (p=0.037), and size (p<0.001) were predictors of OS, while stage (p<0.001) and size (p<0.001) were predictors of DSS. For stage I/II cancers, surgery (p=0.011) and size (p=0.010) were predictors of OS, and size (p=0.001) predicted DSS. For stage III/IV cancers, both radiotherapy (p=0.024, p=0.009) and size (p=0.001, p=0.001) predicted OS and DSS. For tumors ⩽5 cm, stage (p=0.031) predicted DSS. For tumors >5 cm, male gender (p=0.005), stage (p=0.001), surgery (p=0.003), and radiotherapy (p=0.050) were determinants of OS, and male gender (p=0.022), stage (p<0.001), and radiotherapy (p=0.002) were determinants of DSS.

CONCLUSION

Surgical resection confers survival benefit in patients with early stage MPNST, while radiotherapy improves survival in cases with metastatic disease. Surgery and radiotherapy are prognostically important in patients with tumors >5 cm.

Neurogenic tumors of soft tissue

Neurogenic tumors are an uncommon yet important category of soft tissue tumors in children and adolescents because of their frequent association with various genetic syndromes. The heterogeneous cellular composition of the peripheral nerve and the wide metaplastic capacity of the neural crest and its derivatives generate a variety of neoplasms with neurogenic differentiation. This article reviews the clinicopathologic features and differential diagnosis of neurogenic tumors in the first two decades of life, and highlights use of selected ancillary methods for diagnosis.

Malignant Peripheral Nerve Sheath Tumors of the Head and Neck: Two Cases and a Review of the Literature

Malignant peripheral nerve sheath tumors are uncommon lesions that occasionally affect the head and neck. We describe 2 new cases of head and neck pathology. One tumor involved the parotid gland and resulted in erosion of the temporal bone, and the other affected the lower lip. A rapid diagnosis has significant implications for management because of the tumor's potential for aggressive behavior and its high rate of recurrence. To the best of our knowledge, lip involvement is rare and temporal bone involvement has not been previously described.

Malignant peripheral nerve sheath tumour of the spinal accessory nerve

A 50-year-old man presented with a left-sided neck mass. Clinical examination revealed a large fluctuant 7 cm x 7 cm mass in the left posterior triangle. Magnetic resonance imaging (MRI) revealed an encapsulated soft tissue lesion. He underwent exploration of the neck and a 14 cm by 8 cm mass enfolding the accessory nerve was identified and completely excised. Histological examination of the surgical specimen showed features in keeping with a malignant peripheral nerve sheath tumour (MPNST). We present the clinical and pathological features of this condition.

Peripheral Nerve Sheath Tumors of the Thyroid Gland: A Series of Four Cases and a Review of the Literature

Primary peripheral nerve sheath tumors (PNSTs) of the thyroid gland are exceptionally rare. Two schwannomas and two malignant PNSTs (MPNSTs), arising primarily within the thyroid gland, were identified in the files of the Endocrine Tumor Registry at the Armed Forces Institute of Pathology. The patients included two females, age 69 and 80 yr, and two males, age 18 and 33 yr. The patients presented with a mass in the thyroid gland confined to a single lobe of the thyroid without involvement of the cervical neck region. None of the patients had a history of neurofibromatosis. The benign tumors were encapsulated, one of them cystic, with the characteristic cellular and nuclear features of schwannomas. The MPNSTs were invasive tumors, effacing the thyroid parenchyma, with a fascicular pattern of growth composed of neural appearing cells with increased cellularity, increased mitotic activity, and with focal necrosis. Immunoreactivity for 5100 protein and vimentin was seen in all tumors. The patients with schwannomas, treated only by surgical resection, were alive without evidence of disease, over a period of 5-33 yr. Both patients with MPNSTs died of the disease 8 mo and 42 mo, respectively, with widely disseminated disease. Primary thyroid PNSTs are exceptionally rare tumors. MPNSTs, in this limited experience, have a fatal outcome irrespective of aggressive adjuvant therapy.