Parathyroid adenoma

Parathyroid adenoma
	Diagnosis in short
	; Chief cell parathyroid adenoma (left of image) and unremarkable parathyroid gland (right of image). H&E stain. (WC)
LM DDx	parathyroid hyperplasia, parathyroid carcinoma, lymph node, thyroid gland
Site	parathyroid gland (neck/mediastinum)
Syndromes	multiple endocrine neoplasia 1, multiple endocrine neoplasia 2A
Blood work	increased parathyroid hormone, serum calcium increased
Prognosis	benign
Clin. DDx	nodule (lymph node, other tumours), hyperparathyroidism (parathyroid hyperplasia, parathyroid carcinoma), DDx of hypercalcemia
Treatment	removal

Parathyroid adenoma is a common benign pathology of the parathyroid gland.

General

Clinical diagnosis.
Most common cause of primary hyperparathyroidism.^[1]
May be associated with MEN 1 and MEN 2A.

MEN 1:

MEN 2A:

Subtypes

Histologic subtyping:^[2]

Chief cell parathyroid adenoma.
- Common.
Oxyphil parathyroid adenoma.
- Uncommon.^[3]
Mixed.

Gross

One parathyroid is big... the others are small.

Microscopic

Features - general:

Proliferation of parathyroid cells (chief cells, oxyphils or both) lacking adipose tissue.
Classically have a rim of normal parathyroid gland around it^[4] with adipose tissue.

Note:

Generally, it is impossible to discern between parathyroid adenomas and parathyroid hyperplasias by histology alone.^[4]
- One requires information of the size of the other glands to make the diagnosis.

DDx:

Parathyroid hyperplasia - differentiated by clinical history.
Parathyroid carcinoma - destructive invasion of surrounding tissue or far away mets, increased proliferative activity.

Chief cell parathyroid adenoma

Features:^[1]

Chief cells - key feature:
- Small central nucleus.
  - Round with stippled chromatin - important.
- Moderate cytoplasm.
+/-Scattered oxyphil cells:
- Large cells.
- Abundant cytoplasm.
Architecture:
- Nests.
- Circular formations - often around capillaries (perivascular pseudorosettes).

Images

Parathyroid adenoma - low mag. (WC/Nephron)
Parathyroid adenoma - high mag. (WC/Nephron)

Oxyphil parathyroid adenoma

Features:^[1]

Oxyphil cells:
- Large cells.
- Abundant cytoplasm.

DDx:

Hürthle cell adenoma of the thyroid gland.

Image:

Parathyroid adenoma (med.utah.edu).^[5]

Sign out

Note:

One should not say "negative for malignancy".

Parathyroid Gland, Excision:
- Chief cell parathyroid adenoma.

Parathyroid Gland, Excision:
- Chief cell parathyroid adenoma with adjacent normal parathyroid tissue.

Parathyroid Gland (Submitted as "Right Superior Parathyroid Adenoma"), Excision:
- Parathyroid adenoma with adjacent normal parathyroid tissue.

Block letters

PARATHRYOID GLAND, EXCISION:
- CHIEF CELL PARATHYROID ADENOMA.

Micro

The section shows an adenoma consisting predominantly of chief cells. A rim of normal parathyroid is seen adjacent to the adenoma. A small amount of unremarkable adipose tissue is present.

References

↑ ^1.0 ^1.1 ^1.2 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1127. ISBN 978-1416031215.
↑ Moran, CA.; Suster, S. (Nov 2005). "Primary parathyroid tumors of the mediastinum: a clinicopathologic and immunohistochemical study of 17 cases.". Am J Clin Pathol 124 (5): 749-54. doi:10.1309/WJEL-N05L-9A06-9DU0. PMID 16203274.
↑ Fleischer, J.; Becker, C.; Hamele-Bena, D.; Breen, TL.; Silverberg, SJ. (Dec 2004). "Oxyphil parathyroid adenoma: a malignant presentation of a benign disease.". J Clin Endocrinol Metab 89 (12): 5948-51. doi:10.1210/jc.2004-1597. PMID 15579742.
↑ ^4.0 ^4.1 Taxy, J.; Husain, A; Montag, A. (2009). Biopsy Interpretation: The Frozen Section (1st ed.). Lippincott Williams & Wilkins. pp. 191. ISBN 978-0781767798.
↑ URL: http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/enfrm.html. Accessed on: 6 December 2010.

[Ref_PBoD8_1127-1] 1.0 ^1.1 ^1.2 Kumar, Vinay; Abbas, Abul K.; Fausto, Nelson; Aster, Jon (2009). Robbins and Cotran pathologic basis of disease (8th ed.). Elsevier Saunders. pp. 1127. ISBN 978-1416031215.

[pmid16203274-2] Moran, CA.; Suster, S. (Nov 2005). "Primary parathyroid tumors of the mediastinum: a clinicopathologic and immunohistochemical study of 17 cases.". Am J Clin Pathol 124 (5): 749-54. doi:10.1309/WJEL-N05L-9A06-9DU0. PMID 16203274.

[pmid15579742-3] Fleischer, J.; Becker, C.; Hamele-Bena, D.; Breen, TL.; Silverberg, SJ. (Dec 2004). "Oxyphil parathyroid adenoma: a malignant presentation of a benign disease.". J Clin Endocrinol Metab 89 (12): 5948-51. doi:10.1210/jc.2004-1597. PMID 15579742.

[Ref_BITFS191-4] 4.0 ^4.1 Taxy, J.; Husain, A; Montag, A. (2009). Biopsy Interpretation: The Frozen Section (1st ed.). Lippincott Williams & Wilkins. pp. 191. ISBN 978-0781767798.

[5] URL: http://library.med.utah.edu/WebPath/EXAM/IMGQUIZ/enfrm.html. Accessed on: 6 December 2010.

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