A Case of Thyroid Insular Carcinoma with Multiple Bone Metastases Presenting as Pyriform Sinus Mass / 대한이비인후과학회지

Thyroid insular carcinoma (TIC, poorly differentiated thyroid carcinoma) is derived from thyroid follicular cells and known to show pathophysiologic behaviors intermediate between well-differentiated and undifferentiated types of thyroid carcinoma. The estimated incidence of TIC is from 0.4% to 5% of all thyroid cancers and is rare in Asians. Moreover, the multiple bone metastases in TIC have been rarely reported so far. Clinically, there are two pathways that thyroid cancer is presented, either as a parapharyngeal or retropharyngeal mass. For the first pathway, the mass is located on the thyroid upper pole and it grows toward the anatomical defect of posterior aspect of inferior pharyngeal constrictor. The second pathway involves a pharynx directly compressed by the mass from outside to inside of inferior pharyngeal constrictor. A 66-year-old man who had a thyroid mass revealed important clinical findings: a right pyriform sinus mass from laryngoscopy and multiple bone metastases from radiology. We performed subtotal thyroidectomy with central neck dissection. The mass was confirmed as TIC from follicular thyroid carcinoma. The patient received radiation and radioactive iodine therapy, and bcause of a remnant thyroid mass, he was observed closely. We herein report a rare, unique case of TIC with a review of literatures.

Insular Carcinoma of the Thyroid with Jugular Vein Invasion / 대한이비인후과학회지

Insular carcinoma of the thyroid is an uncommon thyroglobulin-producing neoplasm, showing intermediate aggressiveness between well-differentiated follicular carcinoma and undifferentiated anaplastic carcinoma. Although microscopic angioinvasion of insular carcinoma is common, gross invasion of the cervical veins and intraluminal propagation are rarely seen. We encountered a case of a 37-year-old man with an insular carcinoma of the thyroid displaying the aggressive local invasion and angioinvasion of the internal jugular vein. After complete resection of the tumor, postoperative radioactive iodine was administered. The patient survives 12 months after surgery, and no locoreginal recurrence and distant metastasis were noted. Aggressive surgical resection and postoperative radioactive iodine therapy may be indicated in the treatment of insular carcinoma of the thyroid with invasion of the internal jugular vein, as we performed in this case, to achieve locoregional disease control and prolonged survival.

Insular (Poorly Differentiated) Carcinoma of Thyroid / 대한내분비외과학회지

Insular carcinoma of the thyroid is a rare thyroid malignancy, and this was named in 1984 by Carcangiu when he described its characteristic histology. Histologically, insular carcinoma is characterized by uniform cells arranged in distinct nests or an insular pattern that contain variable numbers of small follicles. Clinically and morphologically, it is considered to be in an intermediate position between well-differentiated carcinoma of the thyroid (papillary or follicular) and undifferentiated or anaplastic carcinoma of the thyroid. This thyroid malignancy is distinctive, aggressive and often lethal. However, most authors believe it to be an independent entity. The prognosis of this tumor is worse than that of classic differentiated thyroid carcinoma, and most authors advise aggressive therapy, which can achieve pro-longed survival in some cases. We describe here a patient (a 42 years-old woman) who was managed with completion thyroidectomy after unilateral lobectomy of the thyroid with confirmation of the permanent pathology as insular carcinoma. I-131 ablation (175 mCi) was performed on the remnant thyroid tissues after follow-up of I~131 whole-body scanning.

Immunohistochemical Analysis of Insular Carcinoma of the Thyroid Gland

BACKGROUND: Insular thyroid carcinoma (ITC) is a relatively infrequent thyroid carcinoma that has distinctive histologic features. ITC shows an aggressive clinical course and the predominant presence of an insular component, which has been reported to be an independent factor of a poor prognosis. We retrospectively examined clinical details of the nine ITC patients, which represented 9 years of experience with ITC, and investigated the expressions of variable neuroendocrine and other immunohistochemical markers associated with well-differentiated thyroid carcinomas. METHODS: We adopted an immunohistochemical approach and studied the expressions of synaptophysin, chromogranin A, CD56, NSE, S-100, RET, PPARgamma, calcitonin, galectin-3, and thyroglobulin in formalin-fixed, paraffin embedded tissue array slides of the 9 ITC patients, and investigated clinical features. Seven cases of follicular carcinoma and 4 cases of medullary carcinoma were also included as controls. RESULTS: ITCs were positive for synaptophysin (44%, 4/9), CD56 (11%, 1/9), NSE (89%, 8/9), S100 (67%, 6/9), calcitonin (22%, 2/9), galectin-3 (78%, 7/9), and thyroglobulin (100%, 9/9), but completely negative for chromogranin A, RET, and PPARgamma. CONCLUSION: ITCs express neuroendocrine markers in variable proportions and appear not to be associated with the oncoproteins of conventional thyroid carcinomas. Notably, its differential diagnosis from medullary carcinoma is required in cases showing focal calcitonin positivity.

Clinicopathologic Features of Poorly Differentiated (Insular) Carcinoma of Thyroid

PURPOSE: Well-differentiated carcinomas of the thyroid run an excellent clinical course. However 10~20% of thyroid carcinomas showed poor clinical outcomes. Insular carcinomas are an uncommon thyroglobulin-producing neoplasm, which show intermediate prognosis between well-differentiated carcinomas and undifferentiated anaplastic carcinomas, and their clinicopathologic features are poorly understood. Therefore, we aimed to investigate the clinicopathologic features and the prognosis of insular thyroid carcinomas. METHODS: We reviewed 10 patients who underwent an operation due to an insular thyroid carcinoma at Seoul National University Hospital between January 1990 and December 2001. Their clinicopathologic features and follow-up findings were retrospectively reviewed and compared. RESULTS: Four male and six female patients are reviewed, with a mean age of 54.8+/-6.4187, ranging from 37 to 69 years. Pathologically, eight of the tumors consisted of pure insular carcinoma and the others showed a papillary carcinoma as the major component and a minor insular component. The mean tumor size was 4.53 cm (4.53+/-1.4288 cm). An extrathyroidal extension was present in 7 cases and a vascular invasion in 6. Distant metastasis and local relapse of the regional lymph node were seen in 9 patients. Comparing the survivor and expired groups, all the male patients were in the expired group, and the mean tumor size was larger in the expired group (5.46 cm vs. 3.6 cm). But these differences were not statistically significant. CONCLUSION: Our study revealed that insular carcinomas have distinctive clinicopathologic features, and recognition of this histologic variant is important and significant for management of these unique tumors.

Fine Needle Aspiration Cytology of Insular Carcinoma of the Thyroid / 대한세포병리학회지

Insular carcinoma of the thyroid(ICT) is an uncommon thyroglobulin-producing neoplasm, intermediate between well differentiated and anaplastic carcinoma. Only a few publications have addressed the fine needle aspiration cytologic(FNAC) findings from ICT. We experienced a case histologically diagnosed as ICT and with preoperative FNAC in a 52-year-old woman. The FNAC displayed scanty colloid and abundant monomorphic follicular cells presented singly, in small loose aggregates, and in cohesive trabecular or acinar clusters. Intact insulae of tumor cells were also identified. Necrosis and mitosis were rare. Tumor cells showed round and monomorphic nuclei, finely granular chromatin, and inconspicuous nucleoli. When insular structure is identified in thyroid FNAC specimen, ICT should be included in the differential diagnosis. Herein we discuss and review the cytologic criteria for separation of ICT from other thyroid neoplasms.

Insular Carcinoma: An Aggressive Subtype of Differentiated Thyroid Neoplasms / 대한내분비외과학회지

PURPOSE: Insular carcinoma is a rare subtype of thyroid cancer which was first described by Carcangiu in 1984. Its aggressiveness is intermediate between well differentiated and anaplastic thyroid carcinoma. But its origin, clinical features and prognosis are not yet clearly understood. We wanted to evaluate the clinical features, histologic characteristics and prognosis of insular thyroid carcinoma. METHODS: We studied 4 cases of insular thyroid carcinoma treated in Samsung Medical Center from March 1996 to April 1998. Age, sex, clinical features, treatment, pathology and follow up findings were reviewed, retrospectively. RESULTS: All patients were female and the mean age was 44 years. Three of all patients complained of anterior neck mass and one patient complained of low back pain and paresthesia of the right thigh. Two patients had metastatic bone lesions at the time of diagnosis. Preoperative fine needle aspiration cytology diagnosed follicular neoplasm in 2 cases and papillary carcinoma in 1. We performed total or completion total thyroidectomy and radioactive iodine therapy in 3 cases and radioactive iodine therapy alone in one. Extrathyroidal invasion, vascular invasion and multicentricity were noted in two cases. All four patients showed recurrence or distant metastasis in follow up over a period of 10 to 31 months and 2 of them died of distant metastasis during this follow up period. CONCLUSION: Insular carcinoma is a special type of thyroid carcinoma with aggressive clinical course. Recurrence and extrathyroidal involvements are common and the prognosis is poorer than other well differentiated thyroid carcinomas.

Insular Carcinoma: An Aggressive Subtype of Differentiated Thyroid Neoplasms / 대한내분비외과학회지

PURPOSE: Insular carcinoma is a rare subtype of thyroid cancer which was first described by Carcangiu in 1984. Its aggressiveness is intermediate between well differentiated and anaplastic thyroid carcinoma. But its origin, clinical features and prognosis are not yet clearly understood. We wanted to evaluate the clinical features, histologic characteristics and prognosis of insular thyroid carcinoma. METHODS: We studied 4 cases of insular thyroid carcinoma treated in Samsung Medical Center from March 1996 to April 1998. Age, sex, clinical features, treatment, pathology and follow up findings were reviewed, retrospectively. RESULTS: All patients were female and the mean age was 44 years. Three of all patients complained of anterior neck mass and one patient complained of low back pain and paresthesia of the right thigh. Two patients had metastatic bone lesions at the time of diagnosis. Preoperative fine needle aspiration cytology diagnosed follicular neoplasm in 2 cases and papillary carcinoma in 1. We performed total or completion total thyroidectomy and radioactive iodine therapy in 3 cases and radioactive iodine therapy alone in one. Extrathyroidal invasion, vascular invasion and multicentricity were noted in two cases. All four patients showed recurrence or distant metastasis in follow up over a period of 10 to 31 months and 2 of them died of distant metastasis during this follow up period. CONCLUSION: Insular carcinoma is a special type of thyroid carcinoma with aggressive clinical course. Recurrence and extrathyroidal involvements are common and the prognosis is poorer than other well differentiated thyroid carcinomas.

Insular Carcinoma: An Aggressive Subtype of Differentiated Thyroid Neoplasms / 대한암학회지

PURPOSE: Insular carcinoma is a rare subtype of thyroid cancer which is first described by Carcangiu in 1984. It is intermediate in aggressiveness between well differentiated and anaplastic thyroid carcinoma. But its origin, clinical features and prognosis are not yet clearly understood. We wanted to evaluate the clinical features, histologic characteristics and the prognosis of the insular thyroid carcinoma. MATERIALS AND METHODS: We studied 4 cases of insular thyroid carcinoma treated in Samsung Medical Center from March 1996 to April 1998. Age, sex, clinical features, treatment, pathology and follow up findings were reviewed, retrospectively. RESULTS: All patients were female and mean age was 44 years. Three of four patients complained anterior neck mass and one patient complained low back pain and paresthesia of right thigh. Two patients had metastatic bone lesions at the time of diagnosis. Preoperative fine needle aspiration cytology could diagnose follicular neoplasm in 2 cases and papillary carcinoma in 1. We performed total or completion thyroidectomy and radioactive iodine therapy in 3 cases and radioactive iodine therapy alone in one. Extra- thyroidal invasion, vascular invasion and multicentricity was noted in two cases. All four patients showed recurrence or distant metastasis in follow up period of 10~31 months and 2 of them died of distant metastasis. CONCLUSION: Insular carcinoma is a special type of thyroid carcinoma with aggressive clinical course. Recurrence and extrathyroidal involvements are common and the prognosis is poorer than other well differentiated thyroid carcinoma.

Fine Needle Aspiration Cytoloy of Poorly Differentiated "Insular" Carcinoma of the Thyroid: A Case Report / 대한세포병리학회지

Cytologic features of a poorly differentiated "insular" carcinoma of the thyroid are presented. In fine needle aspiration cytology, the aspirates were highly cellular and tumor cells were arranged in loose clusters or singly dispersed on focally necrotic background. Occasional microfollicles were evident. The tumor cells had poorly defined, scanty cytoplasm and most of the nuclei were fairly uniform with coarse chromatin pattern. A few large pleomorphic cells were also noted. The cytologic findings of the present case were correlated well with the histologic findings, which showed typical insular pattern and the presence of uniform cells with occasional pleomorphism.

Fine Needle Aspiration Cytology of Poorly Differentiated "Insular Carcinoma" of the Thyroid: A Case Report / 대한세포병리학회지

A case of poorly differentiated "insular" carcinoma of the thyroid is presented and discussed with references to the literature. In fine needle aspiration cytology of our case, the aspirates were highly cellular with tumor cells appearing as dispersed isolated cells as well as in dense clusters and syncytial formations. Occasional microfollicles containing colloid were evident. Most of nuclei were fairly uniform with considerable variability and a few showed definite atypical features. Nuclear grooving was additional features. Necrotic debris was not seen. Our cytologic findings were correlated well with histology, confirming typical insular pattern of tumor cells with the presence of occasional pleomorphic cells and papillary carcinoma-like features. With much attention to cytological features of insular carcinoma, it would be possible to diagnose a preoperative suggestive diagnosis, even though not definitive.

Aspiration Cytology of Insular Carcinoma of Thyroid: A Case Report / 대한세포병리학회지

Fine needle aspiration cytologic features of a case of insular carcinoma of the thyroid in a 23-year-old woman who presented a palpable neck mass is described. The aspirate showed cellular smear arranged in trabeculae, solid or loose clusters, and microfollicles in necrotic background. The tumor cells had uniform, small round, hyperchromatic nuclei. The chromatin was finely granular, and nuclear membrane was smooth. Nucleoli were not discernible. Nuclear pleomorphism was minimal. The cytoplasm was usually scanty, pale, poorly outlined, and almostly amphophilic. Sometimes paranuclear cytoplasmic vacuoles were noted. Final diagnosis was confirmed by total thyroidectomy as insular carcinoma.