|Year : 2019 | Volume
| Issue : 2 | Page : 88-90
Incidental detection of papillary microcarcinoma along with follicular adenoma: A report of two cases
Amul K Butti, Shakti Kumar Yadav, Swapna Kaloor Gopinathan, Namrata Sarin, Sompal Singh
Department of Pathology, North Delhi Municipal Corporation Medical College and Hindu Rao Hospital, New Delhi, India
|Date of Web Publication||15-Jul-2019|
Dr. Sompal Singh
Department of Pathology, North Delhi Municipal Corporation Medical College and Hindu Rao Hospital, New Delhi
Source of Support: None, Conflict of Interest: None
Papillary thyroid carcinoma (PTC) is the most common thyroid neoplasms accounting for about 80%–90% of thyroid malignancies. Thyroid papillary microcarcinomas are the subtype of papillary carcinoma, defined as thyroid tumor <1–1.5 cm. They are incidentally encountered in autopsies or surgical specimens or nodular thyroid diseases where malignancy is not suspected. Hence, a meticulous search is mandatory for finding foci of PTC before labeling as benign.
Keywords: Follicular adenoma, incidental papillary microcarcinomas, thyroid
|How to cite this article:|
Butti AK, Yadav SK, Gopinathan SK, Sarin N, Singh S. Incidental detection of papillary microcarcinoma along with follicular adenoma: A report of two cases. Thyroid Res Pract 2019;16:88-90
|How to cite this URL:|
Butti AK, Yadav SK, Gopinathan SK, Sarin N, Singh S. Incidental detection of papillary microcarcinoma along with follicular adenoma: A report of two cases. Thyroid Res Pract [serial online] 2019 [cited 2020 Apr 6];16:88-90. Available from: http://www.thetrp.net/text.asp?2019/16/2/88/262726
| Introduction|| |
Papillary thyroid carcinoma (PTC) is the most common thyroid cancer of follicular epithelial cell origin with distinctive nuclear features. There are many morphological variants of PTC which have been described along with their behavior. In 2004 WHO classification, the definition of papillary microcarcinoma (PMC) has been tightened to include only incidentally discovered papillary carcinoma with <1 cm, but not clinically evident small papillary carcinomas. PTC with foci <1–1.5 cm were also been given the name of occult papillary carcinomas. PMCs have been reported in 22.5% of thyroid glands resected for benign thyroid diseases. Thus, in patients with benign nodular thyroid diseases, the possibility of underlying PMCs should be taken into account for the proper management of patients. We present two cases of PMC thyroid detected incidentally in follicular adenoma.
| Case Reports|| |
A 21-year-old female patient presented with a complaint of midline neck swelling. Clinically, the swelling was more toward the left side of the midline neck, and it was nodular measuring about 6 cm × 3 cm × 2 cm. Ultrasonographic examination of the swelling showed a hypoechoic cystic area, and the provisional diagnosis of the solitary thyroid nodule was made. Fine-needle aspiration cytology of the swelling showed the feature of colloid goiter. This was followed by hemithyroidectomy. On gross examination, the hemithyroidectomy specimen measuring 5 cm × 2.8 cm × 1.8 cm was received. The cut surface showed a single nodule measuring 2 cm × 2 cm containing colloid-filled cystic areas, areas of hemorrhage, and a solid gray-white area measuring 0.6 cm in the maximum diameter [Figure 1]. The periphery of the nodule showed unremarkable normal thyroid tissue. Microscopic examination of the H and E-stained representative sections taken from the nodule (including the gray white areas) revealed a focus of PMC measuring 3.5 mm within the areas of follicular adenoma. The latter was confirmed by immunohistochemical analysis which revealed strong positivity for CK-19 antibodies in the cells of PMC.
|Figure 1: Cut surface of the thyroid gland showing a gray-white nodule at the inferior pole with colloid-filled areas|
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A 31-year-old male patient presented with a complaint of swelling in the anterior midline of the neck, more toward the right side. On palpation, the swelling was firm, moving with deglutition, and nontender. Ultrasonographic examination of the neck revealed a cystic lesion with probable diagnosis of colloid goiter. Fine-needle aspiration cytology of the lesion showed a large number of cystic macrophages and abundant thin colloid. Hemithyroidectomy was done. The specimen received measured 5 cm × 3 cm × 2 cm and was encapsulated gray-brown tissue. The cut surface revealed a single gray-white nodule measuring 2.2 cm × 2.3 cm near lower part of the specimen with colloid-filled areas and few areas of hemorrhage. The periphery of the nodule showed unremarkable thyroid tissue. The representative sections were taken from the nodule and processed routinely for histopathological examination. Microscopic examination of the H and E-stained sections revealed a follicular adenoma with focal PMC [Figure 2]a and [Figure 2]b measuring 3 mm. The latter was confirmed by immunohistochemical analysis using CK19 antibody [Figure 2]c and Human Bone Marrow Endothelial cell marker-1 (HBME-1) antibodies [Figure 2]d.
|Figure 2: Photomicrograph showing papillary-like structures showing nuclear overcrowding and nuclear enlargement with ground-glass-like nuclei (a: H and E, ×40), nuclear crowding and nuclear grooving (b: H and E, ×400) and tumor cell showing CK19 and HBME-1 positivity (c and d: DAB, ×100)|
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| Discussion|| |
PTC has many morphological variants which have been described, and their behavior has been characterized. PMC is the thyroid carcinoma which is clinically undetected preoperatively and hence diagnosed as a benign lesion. Such kind of thyroidectomy specimens can reveal the tumor of size <10 mm. These tumors can also be detected indirectly as they present at times with cervical lymph node metastases. They are also called occult papillary carcinoma, which describes PTC foci of <1–1.5 cm. Occult papillary carcinoma is a cancer found in thyroid subsequent to discovery of metastatic tumor; latent papillary cancer is discovered incidentally in thyroidectomy or lobectomy specimens or at autopsy. Occult or latent papillary carcinomas may or may not be microcarcinomas.
PMCs are usually diagnosed by the combination of clinical, radiological, and laboratory investigations. However, they are often clinically undetected owing to their small size and silent behavior; they are discovered incidentally in autopsy specimens or thyroid specimens removed for other reasons.
Sakorafas et al. reviewed the histopathological reports of patients who are surgically treated for benign thyroid disease to identify patients with PMC. They found that 27 patients were incidentally diagnosed for papillary thyroid microcarcinoma with a mean diameter of 4.4 mm following surgery for presumably benign thyroid disease, multinodular goiter (20), follicular adenoma (6), and diffuse hyperplasia of thyroid (1).
These tumors are usually well differentiated with characteristic papillary architecture as well as cytological and immunohistochemical features. Nuclei have a ground-glass appearance and have grooved nuclei invaginating into the cytoplasm. Immunohistochemical stains reveal positive markers for Thyroid Transcription Factor-1 (TTF-1), thyroglobulin, galectin-3, and HBME-1.
Multifocal lesions are common in PMC and are seen in 20%–46% of patients. A significant number of patients with PMC (up to 40%) show lymph node metastases (usually micrometastases), and these metastases may precede the clinical evidence of tumor in a small percentage of patients.
Autopsy studies suggest that there is a high incidence of incidental PMC, but a significantly high number of these patients (up to 36%) died because of diseases other than thyroid cancer, as they remained asymptomatic throughout their lives, suggesting relatively “benign” biological behavior.
Total or near-total thyroidectomy was considered the procedure of choice by Sakorafas et al. by for all nodular diseases of thyroid initially as this avoids the need for reoperation for patients with incidental PMC. Selected patients with PMC with adverse prognostic factors such as multicentricity, positive lymph nodes, and capsular or vascular invasion are given adjuvant radiotherapy.
PMCs of the thyroid are the most common incidental findings in thyroidectomy samples done for other benign nodular diseases and in the population-based autopsy studies. Hence, there is a requirement for extensive gross examination to be done. PMCs may coexist with other benign and malignant lesions and even if metastasized to lymph node or a distant site they have an excellent prognosis. Although surgical management of PMC is still debatable in English literature, near-total thyroidectomy is routinely practiced.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]