Medullary thyroid carcinoma

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Medullary thyroid carcinoma
Diagnosis in short

Medullary thyroid carcinoma. H&E stain.

LM nuclei with neuroendocrine features (round nuclei with salt-and-pepper chromatin), +/-amyloid deposits (fluffy appearing acellular eosinophilic material), +/-C-cell hyperplasia
Stains congo red +ve (amyloid deposits)
IHC calcitonin +ve, CEA +ve, chromogranin A +ve, synaptophysin +ve, thyroglobulin -ve (usually)
Gross usu. well-circumscribed, white, gray or yellow, gritty, firm
Staging thyroid cancer staging
Site thyroid gland

Associated Dx C-cell hyperplasia
Syndromes multiple endocrine neoplasia IIa, multiple endocrine neoplasia IIb

Prevalence uncommon
Blood work +/-serum calcitonin elevated
Prognosis poor

Medullary thyroid carcinoma, abbreviated MTC, is an uncommon epithelial malignancy of the thyroid gland that may be syndromic.

General

Medical school memory device - 3 M's:

Epidemiology:

  • Very rare.
  • Poor prognosis.
  • May be genetic (MEN IIa/b syndrome).
  • Arises from C cells (which produce calcitonin).

Sporadic tumours

  • ~80%
  • Slightly older age at presentation (~45)
  • Tend to be solitary

Syndromic tumours - typically:[1]

Serology:

  • Serum calcitonin classically elevated.[2]
  • CEA may also be elevated.

Gross

Features:[1]

  • Usu. well-circumscribed.
  • White, gray or yellow.
  • Gritty.
  • Firm.

Image:

Microscopic

Architecture - various

  • Nested with delicate vascular septa
  • Trabecular
  • Tubular/glandular
  • Pseudo-papillary

Cells

  • Polygonal to spindle to small cells
  • Amphophilic, somewhat granular cytoplasm
  • Cells may have a more bizarre appearance
  • Cells may appear to be 'falling apart'due to interstitial oedema.

Stroma

  • +/-Amyloid deposits - fluffy appearing acellular eosinophilic material in the cytoplasm.
  • Stroma is vascular and can show haemorrhage, hyalinised collagen, oedema or metaplastic bone
  • Coarse calcification
  • True psammoma bodies may be present

Nuclei

  • Nuclei with "neuroendocrine features".
    • Small, round nuclei.
    • Coarse chromatin (salt and pepper nuclei).

Surrounding Thyroid

  • +/-C-cell hyperplasia - seen with familial forms of MTC.
    • C cells (AKA parafollicular cell): abundant cytoplasm - clear/pale.

Note:

  • The amyloid is formed from calcitonin.[3]

DDx:

Images

www:

Stains

  • Congo-red +ve (amyloid present) - mnemonic: CRAP -- congo red amyloid protein.

IHC

Features:[4]

EM

  • Neurosecretory granules.
    • Feature seen in neuroendocrine tumours.

Images: Neurosecretory granules (ucsf.edu).

Sign out

Lesion, Liver, Core Biopsy:
- METASTATIC MEDULLARY THYROID CARCINOMA, see comment.

Comment:
Stains/IHC confirm the morphologic findings; the tumour stains as follows:
POSITIVE: calcitonin, CEAp, synaptophysin, CD56, TTF-1 (focal, moderate), congo red (confirms the presence of amyloid).
NEGATIVE: thyroglobulin, CDX2.

Micro

The sections show cells of intermediate size without apparent nucleoli, moderate eosinophilic cytoplasm, arranged in nests, focally associated with amorphous acellular cotton candy-like material.

The cotton candy-like material has a light apple-green appearance when polarized.

See also

References

  1. 1.0 1.1 Nosé, V. (Apr 2011). "Familial thyroid cancer: a review.". Mod Pathol 24 Suppl 2: S19-33. doi:10.1038/modpathol.2010.147. PMID 21455198.
  2. Vainas, I.; Marthopoulos, A.; Chrisoulidou, A.; Raptou, K.; Tziomalos, K.; Pazaitou-Panayiotou, K. (Jul 2013). "Calcitonin stimulation tests for the early diagnosis and follow-up of patients with C cell disease: a descriptive analysis.". Hippokratia 17 (3): 246-51. PMID 24470736.
  3. Khurana, R.; Agarwal, A.; Bajpai, VK.; Verma, N.; Sharma, AK.; Gupta, RP.; Madhusudan, KP. (Dec 2004). "Unraveling the amyloid associated with human medullary thyroid carcinoma.". Endocrinology 145 (12): 5465-70. doi:10.1210/en.2004-0780. PMID 15459123.
  4. URL: http://pathologyoutlines.com/thyroid.html#medullary. Accessed on: 17 January 2011.
  5. SB. 7 January 2010.
  6. de Micco, C.; Chapel, F.; Dor, AM.; Garcia, S.; Ruf, J.; Carayon, P.; Henry, JF.; Lebreuil, G. (Mar 1993). "Thyroglobulin in medullary thyroid carcinoma: immunohistochemical study with polyclonal and monoclonal antibodies.". Hum Pathol 24 (3): 256-62. PMID 8454270.