|Year : 2015 | Volume
| Issue : 2 | Page : 231-233
Poorly differentiated thyroid carcinoma
Sushama Guruwale, Tushar Kambale, Banyameen M Iqbal, Atul Jain
Department of Pathology, Dr. D. Y. Patil Medical College and Research Center, Dr. D. Y. Patil Vidyapeeth, Pimpri, Pune, Maharashtra, India
|Date of Web Publication||13-Mar-2015|
Banyameen M Iqbal
Department of Pathology, Dr. D. Y. Patil Medical College and Hospital, Pimpri, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Poorly differentiated thyroid carcinoma is rare and distinctive due to it's a characteristic uniform cells and sometimes insular architectural pattern. These tumors are aggressive and often lethal type of thyroid tumors often has a rapid and fatal outcome despite appropriate treatment. Here we are presenting a case of a 50 yrs old woman with anterior neck swelling more on right side since five years and increasing in size for the last three months.
Keywords: Insular carcinoma, neck swelling, poorly differentiated thyroid carcinoma
|How to cite this article:|
Guruwale S, Kambale T, Iqbal BM, Jain A. Poorly differentiated thyroid carcinoma. Med J DY Patil Univ 2015;8:231-3
| Introduction|| |
Poorly differentiated thyroid carcinoma (PDTC) is rare and distinct due to its characteristic uniform cells and sometimes insular architectural pattern. These tumors are aggressive and often lethal and have a rapid and fatal outcome despite appropriate treatment. They may represent intermediate entities in the progression of well-differentiated thyroid carcinoma to anaplastic thyroid carcinoma hence they are classified as PDTC. 
| Case Report|| |
A 50-year-old woman admitted to the hospital complaining of a palpable anterior neck swelling more on the right side. The neck swelling is present since 5 years and for the last 3 months it is progressively increasing in size. There is no history of any medication, radiation, or trauma.
On admission, physical examination revealed a swelling, which was mainly confined to the right side, moving with deglutition, and painless. Ultrasonography showed enlarged, heterogeneous thyroid gland with multiple nodules suggesting multinodular goiter. Radio scan showed a cold nodule due to hypofunctioning of thyroid. All laboratory tests thyroid-stimulating hormone, T3 and T4 were within normal limits. Patient was stable. There was no deviation or compression of the trachea. There was no change in voice. No lymph nodes were palpable.
We received a specimen of near total thyroidectomy weighing 90 g, external surface was nodular in appearance, reddish brown in color with a few congested areas. The right lobe measured 6 cm × 8 cm × 4 cm. The upper pole appeared enlarged, globular and on the cut surface showed a nodule measuring 5.5 cm × 4.5 cm × 4 cm, which had a solid and pale cut surface and was partially encapsulated. Rest of the thyroid gland had nodular and colloid cut surface [Figure 1].
|Figure 1: Cut surface showed a well-circumscribed solid nodule which is pale, tan in color|
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A well-circumscribed nodule shows tumor cells arranged in nests and trabeculae. Tumor cells are small round to oval monomorphic with scant to moderate amount of vacuolated eosinopholic cytoplasm having round convoluted hyperchromatic nuclei. These tumor cell nests are separated by thin fibrovascular channels. There is no follicular or papillary pattern. Mitotic figures are >3/10 high power fields. There are foci of micro invasions of stroma. Tumor shows lymphovascular invasion. Necrosis is absent. Rest of the thyroid gland shows changes of multinodular goiter. Based on the above findings the diagnosis of poorly differentiated carcinoma of the thyroid was made [Figure 2] and conformed by immunohistochemistry, which shows cytokeratin-7 diffusely positive, focal positivity for thyroglobulin (TG) and thyroid transcription factor-1 (TTF-1) positive in some of the nuclei. Calcitonin, chromogranin and S-100 were negative. The increased proliferation rate of poorly differentiated carcinoma can be demonstrated by using Ki-67 which is 50-60% in this case  [Figure 3],[Figure 4],[Figure 5],[Figure 6] and [Figure 7].
|Figure 2: Microscopic sections show a typical insular pattern of monotonous round cells with scanty cytoplasm and round nuclei (H and E, ×100)|
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|Figure 3: Micrograph showing Ki-67 positivity with increased proliferation rate of poorly differentiated carcinoma|
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This patient is on follow-up since last 4 months with no complains until date.
| Discussion|| |
Insular carcinoma of the thyroid is derived from follicular epithelium.  The first description and illustration of this tumor was given by Langhans in 1907 using the term "wuchernda struma" (proliferating stroma). He described this lesion characterized by distinct nesting pattern, uniform cells and a peritheliomatous arrangement of the nests in 16 cases of thyroid carcinoma.  Carcangiu et al. in 1984 termed these tumors as poorly differentiated "insular" thyroid carcinoma because the cellular appearance was similar to that seen in the insular type of carcinoid tumors. Since this revised description in 1984, over 200 cases of insular thyroid carcinoma have been described in the literature.  PDTC was described by Sakamoto et al. in 1983 on the basis of presence of nonglandular components with a solid, trabecular, and/or scirrhous growth pattern.  PDTC is in its current definition a distinct type of tumor, and as such has been included as one of the reportable histotypes by the College of American Pathologists protocol for the examination of specimens from patients with carcinomas of the thyroid gland based on the 7 th AJCC/UICC TNM edition (October 2009).  In our case, tumor is partially capsulated, and carcinomas, which are surrounded by a well-defined capsule may even be relatively indolent.  Poorly differentiated carcinoma immunoreactive for TTF-1, which is weaker than conventional follicular and papillary carcinomas and for TG is often focal sometimes displaying a peculiar dot like paranuclear pattern. ,,
| Conclusion|| |
Poorly differentiated thyroid carcinomas account for up to 10% of all thyroid cancers. The rarity of this tumor makes it difficult to draw conclusions regarding its prognosis. PDTC is situated in an intermediate position between well-differentiated (papillary and follicular) and the totally undifferentiated thyroid tumors. Totally, undifferentiated thyroid carcinomas have 50% 5 years survival. Due to the recurrences and metastasize, patients with PDTCs need to be kept under close surveillance and serial monitoring of TG levels can be helpful in detecting recurrences.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]