Gross of thyroid gland

grossing technique for thyroid gland

1. Gross of thyroid gland Presented by – Dr. Monika Nema Monika Nema

2. Anatomy The normal adult thyroid gland is composed of two lobes joined by the isthmus, which lies across the trachea anteriorly , below the level of the cricoid cartilage. Monika Nema

3. Operations on the thyroid gland Nodulectomy - (a procedure largely abandoned that consists of enucleation of a thyroid nodule) L obectomy Monika Nema

4. Operations on the thyroid gland S ubtotal thyroidectomy –in which the posterior capsule and a small portion of thyroid tissue – 1–2 g – are left on the side opposite to the lesion Total thyroidectomy -in which the entire gland – including the posterior capsule – is removed. Monika Nema

5. Grossing procedure Type of specimen received. Orient the specimen. The isthmus can be used to identify the inferior and medial aspects of the gland, the lobes taper superiorly and the posterior surfaces of the lateral lobes have a concave shape caused by the trachea. Measure the specimen. Inspect the posterior aspect of the specimen for parathyroid glands and lymph nodes Monika Nema

6. Palpate the specimen to assess the consistency of the thyroid and to localize any focal lesions before cutting the specimen. Cut parallel longitudinal slices 5 mm each. Capsule is best demonstrated by cutting perpendicular to the long axis of each individual lobe. Once the thyroid is sectioned, sequentially lay out the individual slices in such a way as to maintain the proper orientation of the specimen. Monika Nema

7. Observe the cut surface: smooth or nodular? If an isolated lesion is identified, record its size and location, and determine if it is surrounded by a capsule. If nodular: Mention number, size, and appearance of nodules (cystic? calcified? hemorrhagic? necrotic?) Monika Nema

8. Observe the cut surface: For diffuse lesions: Is the gland symmetrically or asymmetrically involved? Is the lesion confined to the thyroid, or does it extend beyond the capsule of the thyroid into the surrounding soft tissues? Is the lesion cystic or solid, soft or hard, well demarcated or poorly defined? Monika Nema

9. Sections for histology Sections for histology should be taken to demonstrate the following: (1) all components of a lesion (e.g., solid areas and cystic areas); (2) the interface of the tumor (and its surrounding capsule) with the adjacent non- neoplastic thyroid parenchyma; (3) the relationship of the tumor to the thyroid capsule and extrathyroidal soft tissues; and (4) the presence of parathyroids , lymph nodes, and normal-appearing thyroid parenchyma. Monika Nema

10. Sections for histology 1 For diffuse and/or inflammatory lesions : three sections from each lobe and one from isthmus. 2 For a solitary encapsulated nodule measuring up to 5 cm: entire circumference is taken. Take one additional section for each additional centimeter in diameter. Most of these sections should include the tumor capsule and adjacent thyroid tissue, if present Monika Nema

11. Primary task in encapsulated nodule is to make sure that areas of transcapsular or vascular invasion are not missed. Since these areas usually cannot be seen by the naked eye, they can easily be missed unless the peripheral portion of the nodule is extensively sampled. The more capsule sampled, the greater chance of finding invasive foci. Therefore, the tumor –capsule–thyroid interface of any encapsulated nodule should be submitted in its entirety for histologic evaluation. Monika Nema

12. Tangential sections through a round nodule may give the artifactual microscopic impression that the tumor infiltrates the capsule. Monika Nema

13. Decapitate the rounded ends from the tumor nodule To minimize tangential sectioning Monika Nema

14. place the flat surface of each end on the cutting board, and then direct each cut perpendicular to the tumor capsule To minimize tangential sectioning Monika Nema

15. Sections for histology 3 For multinodular thyroid glands : one section of each nodule (up to five nodules), including rim and adjacent normal gland; more than one section for larger nodules. 4 For papillary carcinoma : block entire thyroid gland and (separately) line of resection 5 For grossly invasive carcinoma other than papillary: three sections of tumor , three of non- neoplastic gland, and one from line of resection 6 For all cases : submit parathyroid glands if found on gross inspection Monika Nema

16. Thyroids removed from patients with one of the multiple endocrine neoplasia (MEN) syndromes should be extensively sampled for histology. In gross report, note those sections taken from the middle third of each lobe, as this area is where C-cell hyperplasia and small medullary carcinomas are most likely to be detected. Monika Nema

17. Follicular adenoma Gross appearance of follicular adenomas.Tumor show focal hemorrhagic areas Monika Nema

18. Hashimoto thyroiditis Diffuse and symmetrical enlargement of the gland. The consistency is firm but not stony hard as in Riedel thyroiditis . There is no extension of the process outside the gland. The cut surface is dstinctly nodular, yellowish gray, and greatly resembles a hyperplastic lymph node Monika Nema

19. Dyshormonogenetic goiter The gland is enlarged and multinodular Monika Nema

20. Graves disease (diffuse toxic goiter ) The gland is diffusely swollen and hyperemic . Cut surface of thyroid gland with diffuse hyperplasia, showing a hyperemic ‘juicy’ appearance. Monika Nema

21. Papillary carcinoma Grossly, gland is enlarged,solid,firm.Sometimes the papillary formations are evident to the naked eye. Monika Nema

22. Hürthle cell ( oncocytic ) tumors Grossly, the tumors are solid, tan, and well vascularized Most are well encapsulated throughout. Monika Nema

23. Medullary carcinoma Grossly, the typical tumor is solid, firm, and nonencapsulated but relatively well circumscribed and has a gray to yellowish cut surface Monika Nema

24. Thank you Presentation by- Dr. Monika Nema Monika Nema