Thyroid & parathyroid
Other thyroid malignancies
Plasmacytoma
Author: Sheren Younes, M.D.
Last author update: 1 January 2015
Last staff update: 12 February 2021
Copyright: 2016-2022, PathologyOutlines.com, Inc.
PubMed Search: plasmacytoma thyroid
Table of Contents
Definition / general | Case reports | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Differential diagnosisCite this page: Younes S. Plasmacytoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidplasmacytoma.html. Accessed July 3rd, 2022.
Definition / general
- Rare tumor of thyroid gland, presenting as a mass
- Solitary or associated with multiple myeloma
- Diagnosis should be restricted to tumors without a lymphoid component
Case reports
- 19 year old woman (N Z Med J 2006;119:U2005)
- 53 , 60, 61 and 71 year old men (Blood Res 2014;49:280, J Cytol 2014;31:53, Arch Pathol Lab Med 1981;105:570, The Internet Journal of Head and Neck Surgery 2007;2(1))
- 71 year old man with painless right sided neck mass (Case of the Week #394)
- 78 year old woman (Acta Clin Belg 2015;70:133)
- Gamma heavy chain disease with primary thyroid plasmacytoma (Arch Pathol Lab Med 1986;110:893)
- Plasmacytoma found in goiter (J La State Med Soc 2010;162:338)
Gross images
Images hosted on other servers:
Gray, firm, fleshy
Thyroidectomy specimen
Microscopic (histologic) description
- Dense infiltrate of plasma cells replacing thyroid follicles
- Plasma cells often appear monotonous; may be mature, immature or anaplastic
- Mature plasma cells: basophilic cytoplasm and clock face nucleus
- Immature plasma cells: large irregular nuclei, less condensed chromatin and occasional nucleoli
- Anaplastic plasma cells: significant variation of nuclear size, coarse to vesicular nuclei and prominent nucleoli
- Also multinucleated cells, immunoglobulin inclusions (dutcher bodies or intracytoplasmic crystals)
Microscopic (histologic) images
Case #394
10×
20×
40×
CD79a
CD138
Kappa
Lambda
Images hosted on other servers:
Mature and immature plasma cells
H&E, CD138+
(A) Kappa light chain+
(B) Lambda light chain-
Cytology description
- Cellular; single cell infiltrates with basophilic cytoplasm containing paranuclear hof, round / oval nuclei with cartwheel chromatin, variable pleomorphism, multinucleation
Cytology images
Images hosted on other servers:
Intranuclear inclusion
Congo red+
Positive stains
Negative stains
- CD20, PAX5, TTF1, CK
- Calcitonin
Differential diagnosis
- Plasmacytoid form of medullary carcinoma
- Reactive / inflammatory conditions such as inflammatory pseudotumor
- Thyroid involvement with multiple myeloma
- Thyroid marginal zone lymphoma with extensive plasmacytic differentiation
- Undifferentiated carcinoma
