Thyroid gland

From Libre Pathology
Jump to navigation Jump to search

The thyroid gland is an important little endocrine organ in the anterior neck. It is frequently afflicted by cancer... but the common cancer has such a good prognosis there is debate about how aggressively it should be treated. The cytopathology of the thyroid gland is dealt with in the thyroid cytology article.

The gland frustrates a significant number of pathologists, as the criteria for cancer are considered a bit wishy-washy.

Thyroid specimens

They come in three common varieties

  • FNA (fine needle aspiration).
  • Hemithyroid.
    • Done to get a definitive diagnosis.
    • May be a "completion" - removal of the other half following definitive diagnosis.
  • Total thyroid.
    • Done for malignancy or follicular lesion.

Gross pathology

  • White nodules - think:
    • Lymphoid tissue.
    • Papillary thyroid carcinoma - may be calcified.[1]

Diagnoses

Common

Pitfalls/weird stuff

  • Thyroid tissue lateral to the jugular vein (often referred to as lateral aberrant thyroid tissue) is generally considered metastatic thyroid carcinoma (papillary thyroid carcinoma) even if it looks benign.[2]
    • This dictum is disputed.[3]
    • The level VI and VII lymph nodes are medial to the jugular.
  • Hashimoto's disease may have so many lymphocytes that it mimics a lymph node -- may lead to misdiagnosis of PTC.
  • Parasitic nodule: clump of thyroid that is attached by a thin thread... but looks like a separate nodule; may lead to misdiagnosis of PTC.

Image:

Diagnostic keys

The following should prompt careful examination:[5]

  • Architecture: microfollicular, trabecular, solid, insular.
  • Thick capsule.
  • Necrosis - rare in the thyroid.

Thyroid IHC - general comments

  • Not really useful.
  • Papers with very small sample sizes abound.

Follicular thyroid carcinoma vs. papillary thyroid carcinoma

  • CD31 more frequently positive in follicular lesions.[6]
    • CD31 is a marker for microvessel density.
  • Galectin-3 thought to be positive in papillary carcinoma.[6]
  • HBME-1 thought to be positive in papillary lesions.[7]

Thyroid lesions per WHO

  • Adapted from the Washington Manual of Surgical Pathology.[8]

Adenoma

  • Follicular adenoma.
  • Hyalinizing trabecular tumour.

Carcinoma

  • Mixed medullary and follicular carinoma.
  • Spindle cell tumour with thymus-like differentiation.
  • Carcinoma showing thymus-like differentiation.

Others

Parathyroid glands

  • May make an appearance in the context of thyroid surgery.

Benign

Solid cell nest of the thyroid gland

  • AKA solid cell nest of thyroid.

General

  • Embryonic remnants endodermal origin.[9]
  • Incidental finding.

Note:

Microscopic

Features:[9]

  • Cellular solid or cystic cluster of variable size with:
    • Cuboidal cellular morphology.
      • May have columnar morphology.
    • Moderate-to-scant eosinophilic cytoplasm.
    • Round/ovoid nuclei with finely granular chromatin.
  • +/-Goblet cells (~30% of cases).[12]

DDx:[9]

Images

www:

IHC

Features:[9]

  • p63 +ve.
    • -ve in clear cells.
  • CEA +ve (polyconal).[12]
    • +ve also in clear cells.
  • Chromogranin A +ve ~45% of cases.[12]

Sign out

Solid cell nests of the thyroid gland are usually not reported.

Thyroid gland nodular hyperplasia

Follicular thyroid adenoma

  • AKA follicular adenoma, AKA thyroid follicular adenoma.

Graves disease

Idiopathic granulomatous thyroiditis

  • AKA granulomatous thyroiditis - non-specific term; granulomas may be due a number of causes.
  • AKA subacute thyroiditis.
  • AKA de Quervain thyroiditis.
    • Should not be confused with de Quervain's disease (AKA gamer's thumb) something completely unrelated to the thyroid.

General

  • Women > men.
  • Etiology: possibly viral.[13]

Clinical:

Management:

  • Medical.
  • Rarely surgery.[15]

Microscopic

Features:[16][13]

  • Granulomas with multinucleated giant cells - usu. with engulfed colloid.
  • Lymphocytes.
  • Plasma cells.
  • +/-Fibrosis.

DDx:

Images

Stains

  • ZN -ve.
  • GMS -ve.

Palpation thyroiditis

General

  • Granulomatous inflammation due to palpation.
    • Incidence of granulomas higher in surgical thyroid specimens than autopsies.[13]

Microscopic

Features:[13]

  • Granulomas involving the follicle.
    • Histiocytes within the colloid.

DDx:

Stains

  • ZN -ve.
  • GMS -ve.

Riedel thyroiditis

  • AKA invasive fibrous thyroiditis.[17]

Hashimoto thyroiditis

C-cell hyperplasia

  • Abbreviated CCH.

Adenolipoma of the thyroid

Malignant neoplasm

There are a bunch of 'em. The most common, by far, is papillary.

Papillary thyroid carcinoma

  • Abbreviated PTC.

Insular carcinoma

Follicular thyroid carcinoma

  • AKA follicular carcinoma.

Medullary thyroid carcinoma

  • Abbreviated MTC.

Poorly differentiated thyroid carcinoma

Anaplastic thyroid carcinoma

Lymphomas of the thyroid

General

  • Rare.
  • Increased risk with chronic inflammatory conditions.
  • Fit in the the greater category of MALT lymphoma.

Microscopic

Features:

  • Lymphoepithelial lesion - key feature.
  • Plasma cells.
  • "Overgrowth" - thyroid parenchyma displaced by lymphocytes.

Weird stuff

Hyalinizing trabecular tumour

  • AKA hyalinizing trabecular adenoma.
  • Abbreviated HTT.

Hürthle cell neoplasm

  • AKA oncocytic neoplasm.
  • Also spelled Hurthle cell neoplasm.

Minocycline associated thyroid pigmentation

  • AKA minocycline thyroid.

General

  • Benign pigmentation of the thyroid due to minocycline, an antibiotic.

Gross

Images:

Microscopic

Features:

  • Granular yellow blobs:
    • Location:
      • Intracytoplasmic in the follicule-lining cells, i.e. follicular cells.
      • Intrafollicular.
    • Variable size ~0.5-4 micrometers.

Notes:

  • Pigment described as lipofuscin-like.[22]

Images

Stains

Sclerosing mucoepidermoid carcinoma with eosinophilia

See also

References

  1. BEC. 20 October 2009.
  2. JOHNSON, RW.; SAHA, NC. (Jun 1962). "The so-called lateral aberrant thyroid.". Br Med J 1 (5293): 1668-9. PMC 1958877. PMID 14452106. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1958877/.
  3. Escofet, X.; Khan, AZ.; Mazarani, W.; Woods, WG. (Jan 2007). "Lessons to be learned: a case study approach. Lateral aberrant thyroid tissue: is it always malignant?". J R Soc Promot Health 127 (1): 45-6. PMID 17319317.
  4. URL: http://radiopaedia.org/articles/lymph-node-levels-of-the-neck. Accessed on: 5 November 2012.
  5. SR. 17 January 2011.
  6. 6.0 6.1 Rydlova, M.; Ludvikova, M.; Stankova, I. (Jun 2008). "Potential diagnostic markers in nodular lesions of the thyroid gland: an immunohistochemical study.". Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 152 (1): 53-9. PMID 18795075.
  7. Papotti, M.; Rodriguez, J.; De Pompa, R.; Bartolazzi, A.; Rosai, J. (Apr 2005). "Galectin-3 and HBME-1 expression in well-differentiated thyroid tumors with follicular architecture of uncertain malignant potential.". Mod Pathol 18 (4): 541-6. doi:10.1038/modpathol.3800321. PMID 15529186.
  8. Humphrey, Peter A; Dehner, Louis P; Pfeifer, John D (2008). The Washington Manual of Surgical Pathology (1st ed.). Lippincott Williams & Wilkins. pp. 331. ISBN 978-0781765275.
  9. 9.0 9.1 9.2 9.3 Reis-Filho JS, Preto A, Soares P, Ricardo S, Cameselle-Teijeiro J, Sobrinho-Simões M (January 2003). "p63 expression in solid cell nests of the thyroid: further evidence for a stem cell origin". Mod. Pathol. 16 (1): 43–8. doi:10.1097/01.MP.0000047306.72278.39. PMID 12527712. http://www.nature.com/modpathol/journal/v16/n1/full/3880708a.html.
  10. Ozaki, O.; Ito, K.; Sugino, K.; Yasuda, K.; Yamashita, T.; Toshima, K.. "Solid cell nests of the thyroid gland: precursor of mucoepidermoid carcinoma?". World J Surg 16 (4): 685-8; discussion 688-9. PMID 1413837.
  11. Prichard, RS.; Lee, JC.; Gill, AJ.; Sywak, MS.; Fingleton, L.; Robinson, BG.; Sidhu, SB.; Delbridge, LW. (Feb 2012). "Mucoepidermoid carcinoma of the thyroid: a report of three cases and postulated histogenesis.". Thyroid 22 (2): 205-9. doi:10.1089/thy.2011.0276. PMID 22224821.
  12. 12.0 12.1 12.2 Mizukami Y, Nonomura A, Michigishi T, et al. (February 1994). "Solid cell nests of the thyroid. A histologic and immunohistochemical study". Am. J. Clin. Pathol. 101 (2): 186–91. PMID 7509563.
  13. 13.0 13.1 13.2 13.3 Lloyd, Ricardo V. (2002). Endocrine Diseases (AFIP Atlas of Nontumor Pathology). Toronto: American Registry of Pathology. ISBN 978-1881041733. http://www.amazon.com/Endocrine-Diseases-Atlas-Nontumer-Pathology/dp/1881041735.
  14. Szczepanek-Parulska, E.; Zybek, A.; Biczysko, M.; Majewski, P.; Ruchała, M. (2012). "What might cause pain in the thyroid gland? Report of a patient with subacute thyroiditis of atypical presentation.". Endokrynol Pol 63 (2): 138-42. PMID 22538753.
  15. Volpé, R. (1993). "The management of subacute (DeQuervain's) thyroiditis.". Thyroid 3 (3): 253-5. PMID 8257868.
  16. Mills, Stacey E; Carter, Darryl; Greenson, Joel K; Oberman, Harold A; Reuter, Victor E (2004). Sternberg's Diagnostic Surgical Pathology (4th ed.). Lippincott Williams & Wilkins. pp. 559. ISBN 978-0781740517.
  17. Fatourechi, MM.; Hay, ID.; McIver, B.; Sebo, TJ.; Fatourechi, V. (Jul 2011). "Invasive fibrous thyroiditis (Riedel thyroiditis): the Mayo Clinic experience, 1976-2008.". Thyroid 21 (7): 765-72. doi:10.1089/thy.2010.0453. PMID 21568724.
  18. 18.0 18.1 Sant'Ambrogio, S.; Connelly, J.; DiMaio, D.. "Minocycline pigmentation of heart valves.". Cardiovasc Pathol 8 (6): 329-32. PMID 10615019.
  19. Geria AN, Tajirian AL, Kihiczak G, Schwartz RA (2009). "Minocycline-induced skin pigmentation: an update". Acta Dermatovenerol Croat 17 (2): 123–6. PMID 19595269.
  20. Noble, JG.; Christmas, TJ.; Chapple, C.; Katz, D.; Milroy, EJ. (Jan 1989). "The black thyroid: an unusual finding during neck exploration.". Postgrad Med J 65 (759): 34-5. PMC 2429157. PMID 2780449. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2429157/.
  21. 21.0 21.1 Raghavan, R.; Snyder, WH.; Sharma, S. (Mar 2004). "Pathologic quiz case: tumor in pigmented thyroid gland in a young man. Papillary thyroid carcinoma in a minocycline-induced, diffusely pigmented thyroid gland.". Arch Pathol Lab Med 128 (3): 355-6. doi:10.1043/1543-2165(2004)128355:PQCTIP2.0.CO;2. PMID 14987144.
  22. Gordon, G.; Sparano, BM.; Kramer, AW.; Kelly, RG.; Iatropoulos, MJ. (Oct 1984). "Thyroid gland pigmentation and minocycline therapy.". Am J Pathol 117 (1): 98-109. PMC 1900569. PMID 6435454. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1900569/.