Thyroid & parathyroid
Other thyroid nonneoplastic
Plasma cell granuloma
Author: Andrey Bychkov, M.D., Ph.D.
Last author update: 1 April 2015
Last staff update: 11 August 2021
Copyright: 2015-2024, PathologyOutlines.com, Inc.
PubMed Search: Plasma cell granuloma thyroid
Table of Contents
Definition / general | Terminology | Epidemiology | Pathophysiology | Clinical features | Diagnosis | Radiology description | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosisCite this page: Bychkov A. Plasma cell granuloma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/thyroidpcgranuloma.html. Accessed May 13th, 2024.
Definition / general
- Marked polyclonal plasma cell infiltration with nodular or diffuse thyroid involvement
Terminology
- Also known as plasma cell granuloma type of inflammatory pseudotumor; but sclerosing type of inflammatory pseudotumor of thyroid is mainly composed of spindle cells (Eur Arch Otorhinolaryngol 2009;266:763, Endocr Pathol 2009;20:186)
- Note: at other sites, the term inflammatory myofibroblastic tumor (or inflammatory pseudotumor) is usually used because myofibroblasts are common, and it is understood that some variants will have numerous plasma cells; however, in the thyroid gland, these cases are still called plasma cell granuloma because there are usually marked plasma cell infiltrates and myofibroblasts are usually limited
Epidemiology
- ~ 20 cases reported, mainly middle age and elderly women (range, 18 - 89 years, M/F = 1:4)
Pathophysiology
- Excessive immunological reaction due to diverse stimuli, either infectious or noninfectious (Pathol Res Pract 2007;203:813)
- Intrinsic abnormal plasma cell differentiation as a consequence of an underlying chronic infection or inflammatory condition (Hum Pathol 1985;16:848)
- Autoimmune reactions and a predisposition to autoimmune diseases (J Clin Endocrinol Metab 2004;89:1534)
- IgG4-related immunopathologic processes are probably NOT involved (Int J Surg Pathol 2012;20:500)
Clinical features
- Neck mass with compression signs
- Mainly indolent clinical behavior
- Often accompanied by hypothyroidism or Hashimoto thyroiditis
Diagnosis
- Histology after biopsy or surgery
Radiology description
- Nonspecific; solitary benign nodule or diffuse involvement on ultrasound, cold nodule on scintigraphy
Case reports
- 29 year old man with hard thyroid mass and type 1 diabetes mellitus (Int J Clin Pract 2001;55:335)
- 35 year old woman and 41 year old man with plasma cell granuloma of thyroid associated with Hashimoto thyroiditis (J Clin Endocrinol Metab 2004;89:1534, South Med J 2004;97:598)
- 46 year old woman (Arch Pathol Lab Med 2002;126:595)
- 46 year old man with plasma cell granuloma of thyroid with Hashimoto thyroiditis (Ear Nose Throat J 2003;82:64)
- 50 year old man with plasma cell granuloma of thyroid gland mimicking carcinoma (Pathol Res Pract 2007;203:813)
- 55 year old woman (Endocr Pract 2008;14:611)
- 75 year old woman with inflammatory pseudotumor of thyroid gland showing fibrohistiocytic proliferation (Endocr Pathol 2009;20:186)
- 89 year old woman (J Thyroid Res 2010;2010:840469)
Treatment
- Lobectomy / partial excision for nodular lesion, total thyroidectomy for diffuse form
- Conservative steroid and immunosuppressive therapy (J Clin Endocrinol Metab 2004;89:1534)
- No recurrences / metastases after excision
Gross description
- Nodular form (50% of cases): well circumscribed, nonencapsulated, white, firm round nodule 2 - 5 cm in diameter (J Clin Pathol 1986;39:1105)
- Diffuse form: unencapsulated, firm, gray-white with multinodular appearance (Arch Pathol Lab Med 2002;126:595)
- Thyroid may adhere to surrounding tissue (Cancer 1981;48:830, J Surg Oncol 1989;41:139, Int J Clin Pract 2001;55:335)
Gross images
Images hosted on other servers:
Multinodular
Cut surface
Microscopic (histologic) description
- Abundant benign plasma cells forming sheets inside cellular fibroblastic stroma with residual thyroid tissue
- Variable lymphocytes and histiocytes, and occasional polymorphonuclear leukocytes or eosinophils
- Russel bodies (aggregates of immunuoglobulin) within plasma cells; Russel bodies may form grape-like clusters
- Mott cells (plasma cells with spherical inclusions packed in their cytoplasm, Endocr Pract 2008;14:611)
- Hürthle cell changes of follicular epithelium in thyroid with diffuse involvement
- Rare sclerosing subtype is hypocellular with focal uniform spindle cells / myofibroblasts arranged in fascicles; large histiocytes, lymphocytes, plasma cells and scattered eosinophils are in background
Microscopic (histologic) images
Images hosted on other servers:
Plasma cells, lymphocytes and fibrous tissue
Clumps of plasma cells
Plasma cells around follicular epithelium
CD79a
Kappa and lambda light chains
Positive stains
- Plasma cells: polyclonal kappa and lambda light chains (APMIS 2008;116:167)
- Spindle cells: vimentin, smooth muscle actin
Negative stains
- ALK1 for spindle cells (no positive cases reported so far)
Molecular / cytogenetics description
- No monoclonality by PCR
Differential diagnosis
