Malignant solitary fibrous tumor of the thyroid gland: Report of a case and review of the literature

Abstract

Solitary fibrous tumors of the thyroid gland (T-SFT) are rarely described, with only 21 cases being reported in the English literatures, all showing benign clinical characteristics. We herein present a 76-year-old woman presenting with a 3-month history of rapidly enlarging neck masses and the CT showed masses with partial calcification in the right thyroid lobe. We performed right hemithyroidectomy and isthmectomy with negative margin under general anesthesia. Histologically, the masses consisted of pleomorphic spindle cells with high mitoses and collagen bands. Immunohistochemically, the tumor cells showed positive reactions for CD34, vimentin and bcl-2, then a diagnosis of malignant solitary fibrous tumor of the right thyroid was made. Six months postoperatively, the CT showed the recurrence of the thyroid tumor and the presence of many nodules of varying sizes throughout bilateral pulmonary lobes. To our knowledge, this is the first case of malignant solitary fibrous tumor of the thyroid gland (T-SFT) with local recurrence and pulmonary metastasis and T-SFT must be considered in the differential diagnosis of spindle cells lesions in the thyroid gland. Correct diagnosis of the malignant T-SFT plays an important role in choosing appropriate therapeutic strategies and long-term follow-up is also extremely essential for these patients.

Intrathoracic Thyroid Solitary Fibrous Tumor Presenting with Respiratory Failure

“…Including the patient described here, only 25 patients have been reported in the English literature. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The morphologic, immunohistochemical, and ultrastructural features of the thyroid SFTs are similar to their reported counterparts in other anatomic sites and their clinical outcome is similarly benign.…”

“…The clinical symptoms were variable, including asymptomatic thyroid nodule in 14 patients, progressed mass in 8 patients, asthma in 2 patients and hoarseness in one patient. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The duration of symptoms ranged from one month to more than 10 years. [3][4][5][6][7][8][9][10][11][12][13][14][15][16] The nonspecific symptoms and image…”

“…Among the 16 patients whose follow-up data were available, only one (6%) experienced recurrence and pulmonary metastasis 6 months after operation. 5) Among patients with primary SFT of the thyroid gland, only two presented with intrathoracic goiter. 6) The intrathoracic lesion caused progressive tracheal compression with respiratory failure and therefore was initially misdiagnosed as asthma.…”

Tumor fibroso solitario del tiroides

“…Se ha descrito un solo caso en el que presentó un comportamiento agresivo con recidiva local y metástasis pulmonares durante el seguimiento 10 . Las caracterís-ticas patológicas que sugieren malignidad incluyen una gran celularidad, alta frecuencia de mitosis, evidencia de necrosis y márgenes infi ltrantes 8,11 ; independiente de su ubicación.…”

Solitary fibrous tumor located in the sella turcica: A report of two cases and review of the literature

“…The majority of SFTs exhibit benign behavior and have a good outcome; however, certain cases may have malignant features. In 10-15% of cases, SFT recurrence and/or metastasis may occur; thus, it is difficult to predict the postsurgical course of the disease (10,11).…”