As to my mind we must do few radiological steps: 1. sonography; 2.dopplerography; and finaly PET/CT.

More that a century ago, the precense of thyroid tisue in a lympho gland was call estopic thyroid tisue. In our days that finding, is compatible only with metastatic disease

The presence of papillary thyroid Ca in a cervical nodes (confirmd by immuno of the node) requires:

1. initially an USS of the neck to look for a solid thyroid node (consistent with a primary tumour)

2. and then a CT of neck and chest to view the extent of lymphadenopathy. (PET CT may be helpful if available)

Once confirmation of papillary thyroid metastaes is made (either by US guided FNA of the node or open biopsy and histology depending on local cytological expertise) I would recommend a total thyroidectomy and block dissection of the neck nodes on the affected side. The patient would then need a iodine uptake scan and iodine I131 radiotherapy treatment. Later they will require TSH suppression with thyroxine (~200mcg/day)

fine needle aspiration biopsy and Tg washout will give a comprehensive solution for thyroid cancer metastasis

The concept of "benign" thyroid tissue in lymph nodes is an antiquated and incorrect diagnostic possibility. The presence of ANY thyroid tissue in a lymph node (confirmed by positive staining with thyroglobulin (best), alternatively TTF1 & PAX-8) indicates lymph node metastases from a primary thyroid carcinoma. There has been some past controversy regarding "lateral" aberrant benign thyroid tissue, thought to have been "pinched off" from strap muscles; however, such EXTREMELY rare findings are not found within the milieu of lymphatic tissue. To reiterate, a pathological diagnosis of "benign thyroid tissue in a lymph node" would be considered inappropriate and a manifestation of poor pathological judgement.

Presence of thyroid tissue in the lymphnodes strongly favors metastasis and ectopic thyroid tissue are so rare that should not be considered unless thyroid and thyroglossal ducts were completely free of disease. Even in that case you should follow patient closly as small foci of cancer in thyroid slices may be missed by pathologist.

The difference between papillary and follicular thyroid tissue iin cervical lymph nodes is really unnecessary since any thyroid tissue in lymph nodes is considered metastatic. Unless you see Psammoma bodies, it's very difficult to differentiate the two cell types. The main concern is that this scenario requires treatment for metastatic thyroid disease, ie, total body I-131 ablation and profound TSH suppression. Both follicular and papillary tumors are adequately treated with this regimen, and long term survival/cure is excellent. Surveillance is then by periodic total body I-131 scan after TSH stimulation.

Presence of thyroid tissue in the lymphnodes strongly favors metastasis and ectopic thyroid tissue are so rare that should not be considered unless thyroid and thyroglossal ducts were completely free of disease. Thyroid tissue in a node is a metastasis as long as known!!!

Any thyroid tissue in a lymph node should be considered to be metastatic disease from a primary thyroid cancer and should be managed as such. This would include total thyroidectomy, formal neck dissection (no "cherry-picking") and post-operative radioactive Iodine.

Any abberant thyroid tissue found in cervical lymp nodes is considered metastasis from a thyroid cancer unless proved otherwise. As a rule, extensive diagnostic workup should me made to rule out differentiated thyroid carcinoma, as the origin. This may include FNB(Fine Needle Biopsy) under the guide of ultrasonography from any suspicious lesion in the thyroid or neck.

However, the primary lesion in the thyroid may have regressed(T0 or Tx).

As the phisician in charge of the patient with this finding, it is always difficult to balance the best profit of the patient and the extent of intervention.

A Quatation from Ioachim's Lymph node Pathology 4th ed. section VI, lymph node inclusions p283-285

Incidental findings of colloid-containing thyroid follicles at radical dissection of the neck for various squamous carcinomas or melanomas of the head and neck have been reported occasionally. None of these was detected grossly, and the incidence was only about 1 in 100 neck dissections. When the thyroid glands were later examined histologically, no primary carcinomas were found.

However, Butler and Collegues showed the presence of an occult primary carcinoma of the thyroid in 16 of 22 patients who had thyroid follicles incidentally found in regional cervical lymph nodes. The authors believe that the benign histologic appearance and lack of a papillary component in the thyroid follicles present in cervical lymph nodes do not preclude their being metastatic. Although clinically occult, the primary thyroid carcinoma in the studied cases was found after careful sectioning of the gland, and it usually contained papillary in addition to follicular areas.

Whether thyroid follicles within cervical lymph nodes represent metastases of occult thyroid carcinomas or embryonic malformations has not been resolved, and definitive diagnosis may not be always possible.

-------------------------------------------------------------------------------------------

In korea, thyroid cancer is the most common cancer among women and men. I guess I have seen many cases of thyroid inclusion follicles in lymph node either benign and malignant patients. But there are not so many descriptions about this matter in many textbooks. I guess thyroid inclusion is not a rare feature whether it designates benign or metastatic malignant. And Not all of these inclusions are indicating metastatic even in thyroid cancer patients. I was asking for a help to differentiating these lesions more scientifically (e.g. immunohistochemical staining or other ancillary molecular tests).

Is there anyone who has been struggling with this matter and found any suggestions?

Thyroid tissue in lymph nodes is metastatic. There was a concept of "thyroid rests" in the lateral neck, but were found to be metastatic tumor in cervical lymph nodes. The often low aggressiveness of papillary cancer, may have led to this notion, but has been shown to be not benign.

What if the thyroid tissue in the lymph node is really benign-looking and normal "follicular cells-like" compared with the the primary "papillary carcinoma " in thyroid gland? I mean cytologically and in architecure these two lesions are completely different. Would it be appropriate to call it metastases ?

International Journal of Surgical Pathology 20(6) 564–569.

The criteria proposed by Rosai et al5 and clinical and radiological correlation will be helpful.

When thyroid tissue replaced one third or more of the node or when several nodes were affected, the diagnosis of metastases should be preferred. Presence of psammoma bodies is diagnostic of metastasis. For intranodal thyroid tissue to be regarded as a possible benign inclusion, it should be restricted to a few small follicles located in or immediately beneath the nodal capsule, and these follicles should not demonstrate any cytoarchitectural features of papillary carcinoma.

The presence of thyroid "benign" tissue in a lymph node is a wrong concept. When thyroid follicular cells are found in a lymph node it means that the diagnosis of a thyroid cancer is mandatory to be excluded

It is also becoming increasingly evident that the diagnosis of papillary microcarcinoma is not the same as papillary carcinoma. small (

I don't agree with many of the previous comments. Although is it obvious that thyroid tissue in cervical lymph node probably represents metastatic PTC and that a Primary should be excluded, there is absolutely no reason to rule out the concept of benign ectopic thyroid tissue in lymph node, much the same way as you can also find benign melanocytic and glandular inclusions in lymph nodes which do not represent metastatic melanoma or carcinoma, respectively. The concomitant or subsequent finding of a papillary microcarcinoma (miPTC) in the thyroid gland does not prove that the thyroid tissue in lymph node is metastatic since miPTC is extremely common and is often an incidental finding in thyroid resection specimens. Moreover, ectopic benign thyroid tissue can also be found in many organs other than lymph nodes including adrenals, and in many of these cases, even after thorough investigations and long term follow-up, no evidence of a thyroid cancer can be found. Therefore, it is not as simple as just considering any thyroid tissue in lymph node as metastatic. That would be too easy, although benign thyroid tissue in lymph should represent a diagnosis of exclusion. Clinical correlation is very important, and if there is enough tissue available, molecular analysis (eg BRAF, RAS, RET/PTC) and/or immunohistochemistry (eg HBME-1, cyclin-D1) might also help to support the metastatic nature of the thyroid tissue in lymph node.

I have been told that there is one immunostain that is negative in papillary carcinomas, but positive in all other epithelial thyroid lesions / malignancies / neoplasms. Can anyone here enlighten me - which stain is that?

Thank you in advance.

CD56? but the specificity seems variable. I use an immunopanel (HBME-1, CD56, CK19 and HMWCK) as ancillary study instead relying on one single immunostain.

Neck Node with thyroid tissue is thyroid metastatic neoplasia

In contrast to benign follicular cells, both CD56 and CD117 are downregulated in PTC. Hence, in addition to galectin-3 and HBME-1 (which are overexpressed in PTC), CD56 and CD117 may be potentially helpful, as negative markers, to distinguish benign thyroid tissue from PTC including in a lymph node.