Malignant peripheral nerve sheath tumor of the thyroid: a clinicopathological and ultrastructural study of one case

Primary schwannoma of the thyroid gland: analysis of case characteristics and review of the literature

BACKGROUND

To improve the characteristics of primary thyroid schwannomas (PTS) and to provide reference basis for clinical diagnosis and treatment.

METHODS

PubMed was searched for case reports of PTS up to December 2022 using the search terms "Thyroid nerve sheath tumor" or "Thyroid schwannoma" or "Thyroid Neurilemmoma", respectively. 34 cases were screened.

RESULTS

PTS can occur at any age, nodules averaged 3.9 cm. The most common symptoms were voice change and dysphagia. Fine needle aspiration cytology showing spindle-shaped cells should be considered for schwannoma. Most cases underwent thyroid lobectomy or nodule removal with a good prognosis. Tissue types with both Antoni A and Antoni B features are common. Positive immunohistochemical staining for S-100 protein, CD34 and waveform proteins helped confirm the diagnosis.

CONCLUSIONS

Positive immunohistochemistry for S-100 and wave proteins helps confirm the diagnosis. Preoperative diagnosis is challenging, but pathology and immunohistochemical staining are the gold standard for diagnosis. The first choice of treatment is surgical resection of the nodules, the prognosis is good.

Neck Surgery for Non-Well Differentiated Thyroid Malignancies: Variations in Strategy According to Histopathology

Lymph node metastases in non-well differentiated thyroid cancer (non-WDTC) are common, both in the central compartment (levels VI and VII) and in the lateral neck (Levels II to V). Nodal metastases negatively affect prognosis and should be treated to maximize locoregional control while minimizing morbidity. In non-WDTC, the rate of nodal involvement is variable and depends on the histology of the tumor. For medullary thyroid carcinomas, poorly differentiated thyroid carcinomas, and anaplastic thyroid carcinomas, the high frequency of lymph node metastases makes central compartment dissection generally necessary. In mucoepidermoid carcinomas, malignant peripheral nerve sheath tumors, sarcomas, and malignant thyroid teratomas or thyroblastomas, central compartment dissection is less often necessary, as clinical lymphnode involvement is less common. We aim to summarize the medical literature and the opinions of several experts from different parts of the world on the current philosophy for managing the neck in less common types of thyroid cancer.

Primary Mesenchymal Tumors of the Thyroid Gland: A Modern Retrospective Cohort Including the First Case of TFE3-Translocated Malignant Perivascular Epithelioid Cell Tumor (PEComa)

Primary mesenchymal tumors of the thyroid gland are extremely rare, with only case reports and small case series documented in the English literature, many of which were published prior to the era of molecular pathology. In the current study, we aim to present a contemporary multi-centric cohort of thyroid mesenchymal tumors. Nineteen primary thyroid mesenchymal tumors were collected from three tertiary centers. Their clinicopathologic features, immunoprofile, molecular alterations, and outcome were described. Eight cases were classified as benign or intermediate with solitary fibrous tumor being the most common histotype (n = 3). The remaining 11 cases were malignant, including three angiosarcomas, one epithelioid hemangioendothelioma, one adamantinoma-like Ewing sarcoma, one biphasic synovial sarcoma, one malignant melanocytic peripheral nerve sheath tumor (melanotic schwannoma), one myxofibrosarcoma, and two undifferentiated pleomorphic/spindle sarcomas (one of which was radiation-induced). Six tumors showed characteristic diagnostic translocations. We herein also described the first case of thyroid malignant perivascular epithelioid cell tumor (PEComa) with RBM10-TFE3 fusion in a 35-year-old female patient. Thyroid mesenchymal tumors, benign or malignant, are rare with a broad spectrum of possible diagnoses. A comprehensive examination to include histology, immunohistochemistry, and molecular testing is essential for the correct diagnosis and to distinguish them from anaplastic thyroid carcinoma. PEComa may occur as a primary tumor of the thyroid gland, expanding the histologic spectrum of thyroid mesenchymal tumors.

Malignant peripheral nerve sheath tumour of thyroid: a diagnostic dilemma

Malignant peripheral nerve sheath tumours of thyroid are rare entities that can present a diagnostic dilemma. We present the case of a patient who presented with neck mass with a history of multiple neck surgeries and airway compression. The patient's previous histopathology was mistaken for Riedel's thyroiditis in an outside hospital, which delayed appropriate treatment leading to suffering on part of the patient and frustration on part of the physician. We emphasise that rare malignancies should be considered in rapidly growing neck masses that are causing airway compression, and histopathology of such tumours should be reported by expert pathologists.

Clinicopathological features of primary thyroid leiomyosarcoma without Epstein-Barr virus infection: A case report

Primary thyroid leiomyosarcoma (LMS) is a rare tumor type with an unusual location, the diagnosis is based entirely on histological and immunohistochemical evaluations. In the present study, a rare case of a 74-year-old female patient who exhibited a right anterior neck mass for 12 months, which rapidly enlarged for the last 3 months. Ultrasound of the thyroid revealed a 55×42 mm hypoechoic mass with clear margins in the right lobe. Histological examination of the tumor demonstrated malignant spindle cells in interlacing fascicles and whorls. Additionally, nuclear pleomorphism, tumor giant cells, necrosis and abnormal mitotic figures were observed. The immunohistochemistry indicated that the tumor cells were strongly positive for smooth muscle actin, desmin, p53 and vimentin expression, but negative for cytokeratin, epithelial membrane antigen, thyroid transcription factor-1, paired box-8, 34βE12, cytokeratin 5/6, cluster of differentiation (CD)117, myoglobin, S100, p16. The final histopathological diagnosis was primary thyroid LMS.

Primary peripheral nerve sheath tumors of the thyroid gland: A case report and literature review

Primary peripheral nerve sheath tumors (PNSTs) of the thyroid gland are rare, with fewer than 30 cases reported in the medical literature to date. Primary PNSTs of the thyroid gland are classified into malignant and benign PNSTs. The benign PNSTs may be further subclassified into neurofibromas and Schwannomas. This is the case report of a 51-year-old male patient presenting with multiple primary PNSTs involving the left lobe of the thyroid gland. The patient underwent total excision of the thyroid gland and the pathological results indicated a Schwannoma with Antoni type A and B cells. The literature was reviewed briefly and, to the best of our knowledge, this is the first case report of multiple primary PNSTs of the thyroid gland.

Leiomyosarcoma: a rare tumor of the thyroid

Primary leiomyosarcoma of the thyroid gland is uncommon. To date, 20 cases have been reported in English in the literature. The tumors usually present in elderly patients with female predilection and are associated with poor clinical outcome. Herein, we report an additional case of primary thyroid leiomyosarcoma in a 64-year-old woman. She underwent total thyroidectomy and later was discovered to have multiple lung and liver metastases. The patient died 3 months after surgery. The major differential diagnoses including undifferentiated (anaplastic) carcinoma of the thyroid, spindle cell variant of medullary thyroid carcinoma, spindle cell tumor with thymus-like differentiation, uncommon primary tumor of the thyroid and metastatic tumors with predominant spindle cells are discussed.

Primary peripheral nerve sheath tumors of the thyroid gland

BACKGROUND

Primary peripheral nerve sheath tumors (PNSTs) of the thyroid gland are exceptionally rare tumors that usually present as asymptomatic neck nodules in adults. This article presents a literature review of these tumors.

SUMMARY

PNSTs of the thyroid can be classified into benign and malignant. Only three cases of malignant PNSTs have been reported. Benign PNSTs of the thyroid include neurofibromas and schwannomas. Only two cases of isolated neurofibroma of the thyroid have been reported. Schwannomas are typically benign, slow-growing tumors that originate from neuronal schwann cells, with a clinical picture depending on the anatomic size and site. Pathologically, schwannomas are classified into Antoni A and Antoni B. Only 17 cases of schwannomas of the thyroid exist in literature to date.

CONCLUSIONS

Schwannomas of the thyroid gland are extremely rare and usually asymptomatic. Complete surgical resection is mandatory for care.