Malignant fibrous histiocytoma metastatic to the thyroid gland

Rare case of metastatic liposarcoma to the thyroid gland and a review of the literature of metastatic sarcomas to the thyroid

BACKGROUND

Liposarcomas are the second most common type of soft tissue sarcomas. Typically, myxoid liposarcomas have a metastatic rate of 10%, usually involving the retroperitoneal space, abdomen, and spine. Metastasis to the thyroid is extremely rare.

DESIGN/METHOD

A 62-year-old male with a history of metastatic myxoid liposarcoma in his right thigh presented to our clinic for evaluation of a thyroid nodule incidentally identified on a CT scan. A subsequent FNA biopsy was suggestive of a metastatic liposarcoma.

RESULTS

The patient underwent a left thyroid lobectomy and final pathology confirmed a grade II/III metastatic myxoid liposarcoma that measured 3.3 cm. The patient tolerated the procedure well.

CONCLUSIONS

Our case highlights the role of a patient's medical history when evaluating thyroid nodules to optimize accurate diagnosis, as liposarcomas do not typically metastasize to the thyroid. We also provide an updated review of the literature on all cases of metastatic sarcomas to the thyroid.

Primary Sarcomas of Thyroid Gland-Series of Three Cases with Brief Review of Spindle Cell Lesions of Thyroid

Primary Malignant Fibrous Histiocytoma (MFH-T) and Leiomyosarcoma (LMS-T) of the thyroid gland are extremely rare tumors. Very few cases have been reported in the literature. Both entities occur more commonly in women than men. The closest clinical and histological differential diagnosis is anaplastic carcinoma of thyroid. We present three cases of rare primary sarcomas of thyroid gland. Case-1 was a 63-year-old woman and Case-2 was a 52-year-old woman. Both of them presented with a rapidly increasing thyroid mass clinically mimicking anaplastic carcinoma (AC-T). Both the patients developed pulmonary metastasis and succumbed to the illness soon after the diagnosis of MFH-T was made. Case 3 was 65-year-old woman with neck swelling since six months diagnosed as LMS-T. The present communication adds three new cases to the literature on sarcomas of thyroid gland with an emphasis on differential diagnosis of spindle cell lesions of thyroid. MFH-T and LMS-T needs to be differentiated from AC-T, metastatic sarcomas, spindle cell variant of medullary carcinoma, synovial sarcoma, fibrosarcoma; final diagnosis rests on histopathology and immunohistochemistry.

An extraordinary case of mesenchymal chondrosarcoma metastasis in the thyroid

Secondary tumours of the thyroid gland account for 1.25 to 3 % in clinical series and reach 24 % in autopsy series. Chondrosarcoma is a rare malignant mesenchymal tumour of chondrogenic nature; the mesenchymal variant represents less than 3 % of all chondrosarcomas, being therefore extremely rare. A mesenchymal chondrosarcoma metastasis in the thyroid is exceptional; to our knowledge, only three previous cases of chondrosarcoma metastasis in the thyroid have been reported to date but none of such cases corresponded to a mesenchymal chondrosarcoma. We present the first of such a case in a 27-year-old woman with a 4-year history of mesenchymal chondrosarcoma of the sacrum that was treated by surgery and chemotherapy. At the present admission, head and neck computed tomography revealed a well-defined nodule in the thyroid gland. The diagnosis of metastasis from the mesenchymal chondrosarcoma was made in the right lobectomy specimen.

Primary malignant fibrous histiocytoma of the thyroid: review of the literature with two new cases

Primary malignant fibrous histiocytoma of thyroid is extremely rare. Only three cases have been reported. We report two cases of this rare disease. Case 1 was a 70-year-old woman who had Graves' disease and a growing 3.5-cm thyroid nodule with constrictive symptoms. Fine-needle aspiration cytology showed suspicious atypical cells. She had a total thyroidectomy; frozen section showed sarcoma. Final pathology showed malignant fibrous histiocytoma. Case 2 was a 67-year-old woman who had a 5-cm thyroid nodule that rapidly grew, causing tracheal deviation. A diagnostic lobectomy and pathology showed malignant fibrous histiocytoma. She then had a completion total thyroidectomy. Neither patient had metastatic lesions found by whole body gallium scans, computerized tomographic scans, and neck sonography. Both patients had postoperative radiotherapy and were alive and without recurrence at 6 months follow-up.

Phyllodes Tumor Metastatic to Thyroid HürthleCell Adenoma

We present a case of a malignant phyllodes tumor metastasizing to a Hürthle cell adenoma of the thyroid. A 55-year-old woman underwent mastectomy for a malignant phyllodes tumor. Two years later, she presented with a left thyroid mass, which was a single, circumscribed, soft, deep red-brown nodular lesion with an eccentric area of firmer consistency. Histologically, the thyroid tumor was composed of 2 distinct types of cellular proliferation. Atypical spindle cells were infiltrating between the Hürthle cell cords and follicles in a fibrosarcomatous pattern. A battery of immunohistochemical stains was applied to both the thyroid and breast tumors for comparison. Based on the histologic and immunophenotypic features of the fibrosarcomatous components of both the breast and thyroid tumors, we rendered a diagnosis of cystosarcoma phyllodes metastatic to Hürthle cell adenoma. To the best of our knowledge, this unusual case is a first report of tumor-to-tumor metastasis of a sarcoma to a primary thyroid neoplasm.

Pleomorphic liposarcoma metastatic to the thyroid gland

Although carcinoma is rarely metastatic to the thyroid gland, it has an established place in the differential diagnosis of cold nodules on radionuclide thyroid scans in patients with known cancers. A case of metastatic pleomorphic liposarcoma with involvement of the thyroid gland adds to the list of cases of metastases to the thyroid gland. A patient with known metastatic pleomorphic liposarcoma with a palpable thyroid nodule of 2 months' duration had a thyroid scan with 130 MBq (3.5 mCi) Tc-99m pertechnetate. The scan showed a cold nodule occupying most of the right lobe of the thyroid. Cytologic analysis of a fine-needle aspirate from this cold nodule confirmed metastasis from the known primary cancer, pleomorphic liposarcoma. In a patient with a known primary tumor, a nodule in the thyroid gland should be considered a metastatic lesion, regardless of the time since the primary tumor was diagnosed and treated, until proved otherwise.