Diagnosis and Management of Extracranial Head and Neck Schwannomas: A Review of 27 Cases

Abstract

Objectives. Clinical records of 27 patients with extracranial head and neck schwannoma were retrospectively reviewed. Methods. Ultrasonography (US) was performed in all cases. Seven patients underwent CT. Twenty-five patients underwent MRI. Fine needle aspiration cytology (FNAC) was performed for 12 of the 27 patients. Clinical history, surgical data, and postoperative morbidity were analyzed. Results. The images of US showed a well-defined, hypoechoic, primarily homogeneous solid mass. At CT, only one of 7 cases (14%) was able to suggest the diagnosis of schwannoma. At MRI, twenty of 25 cases (80%) suggested the diagnosis of schwannoma. Only three of 12 cases (25%) displayed a specific diagnosis of schwannoma rendered on FNAC. The distribution of 27 nerves of origin was 10 (37%) vagus nerves, 6 (22%) sympathetic trunks, 5 (19%) cervical plexuses, 3 (11%) brachial plexuses, 2 (7%) hypoglossal nerves, and 1 (4%) accessory nerve. Complete tumor resection was performed in 11 patients, and intracapsular enucleation of the tumor was performed in 16 patients. The rate of nerve palsy was 100 (11/11) and 31% (5/16). Conclusions. MRI is sensitive and specific in the diagnosis of schwannoma. Intracapsular enucleation was an effective and feasible method for preserving the neurological functions.

Extracranial head and neck schwannomas: A series of 14 patients

“…[11] The diagnostic sensitivity of MRI has been stated as 80%. [13] In our series MRI findings suggested the diagnosis of schwannoma in all patients (100%). Fine needle aspiration biopsy also plays a role in differential diagnosis but is not sensitive enough.…”

“…[12] The US primarily suggests a hypoechoic, homogeneous mass including cystic and lobulated components but has poor diagnostic sensitivity. [3,13] In our research, all neck masses were preoperatively examined with a neck US. Computed tomography and MRI were performed in all cases.…”

“…Fine needle aspiration biopsy also plays a role in differential diagnosis but is not sensitive enough. [13] Additionally, facial schwannomas, to avoid the risk of facial paralysis, are not usually subjected to FNAB. [2] In our data, FNAB provided a specific diagnosis in eight cases (57%).…”

“…[14] Accordingly, the definitive diagnosis is established by histopathologic examination of the surgical specimens. [5,13] Histologically, schwannomas have characteristic growth patterns, named Antoni A and Antoni B types, which reveal the clear-cut diagnosis. [5] The use of immunohistochemical S-100 protein also assists in identifying Schwann cells.…”

“…During surgery, despite the low malignant degeneration and recurrence rate, it should be important to remove the whole mass. [11,13] Extracranial head and neck schwannomas ineligible for surgical treatment should be considered for radiotherapy. [17] Recent data supports radiotherapy in schwannomas originating from cranial nerves III-VI for nonsurgical candidates resulting in local control rate of 90-100%.…”