Thyroid gland
Bethesda systems for cytology
Suspicious for malignancy

Topic Completed: 1 June 2014

Minor changes: 8 November 2019

Copyright: 2014-2018,, Inc.

PubMed Search: Bethesda guidelines suspicious for malignancy

Phillip A. Williams, M.D., M.Sc.
Shahid Islam, M.D., Ph.D.
Page views in 2019: 1,764
Page views in 2020 to date: 628
Cite this page: Williams P, Islam S. Suspicious for malignancy. website. Accessed May 27th, 2020.
Definition / general
  • Use when some features of malignancy present, but lack definitive diagnostic changes
  • Based upon the 2009 Bethesda system for thyroid cytopathology (Am J Clin Pathol 2009;132:658)
  • Papillary carcinoma is most often considered in this diagnostic category
  • Other malignancies more commonly considered include medullary thyroid carcinoma, lymphoma and metastases
  • Risk for malignancy is 60 - 75%
  • Suspicious for papillary carcinoma:
    • Sparsely cellular specimen pattern: features of papillary carcinoma but sparse cellularity
    • Focal nuclear changes present: moderate to marked cellularity, benign follicle cells (e.g., macrofollicles) admixed with cells with large nuclei, nuclear grooves, nuclear clearing and nuclear molding, rare / absent nuclear pseudoinclusions only focally present
    • Incomplete nuclear changes pattern: sparse, moderate or marked cellularity with generalized mild to moderately increased nuclear size, mild nuclear clearing and conspicuous nuclear grooves, but only minimal molding or irregular nuclear membranes and only rare / absent intranuclear pseudoinclusions
    • Cystic degeneration pattern: scattered follicular cells in groups or sheets with large pale nuclei and some grooves, but no intranuclear pseudoinclusions; calcifications reminiscent of psammoma bodies may be present; also hemosiderin-laden macrophages
    • Suspicious for medullary carcinoma: sparse to moderate cellularity, monomorphic population of discohesive cells, small to medium size, high N/C ratio, nuclei eccentrically located with smudged chromatin, no readily identified cytoplasmic granules
    • Suspicious for lymphoma: cellular sample with monomorphic small / medium lymphoid cells or sparse cellularity with atypical lymphoid cells
  • Suspicious for papillary thyroid carcinoma: surgical intervention with lobectomy or total thyroidectomy
  • Suspicious for medullary carcinoma or lymphoma: consider ancillary testing (e.g., serum calcitonin, immunohistochemistry for calcitonin for medullary, flow cytometry for lymphoma)
  • Suspicious for metastatic carcinoma: surgery may not be indicated
Sample reports
  1. Suspicious for malignancy
  2. Suspicious for papillary carcinoma
Cytology images

Images hosted on PathOut server:

Contributed by Ayana Suzuki, Cytotechnologist, Japan:

Suspicious for PTC

Suspicious for lymphoma

Hyalinizing trabecular tumor

Images hosted on other servers:

Suspicious for metastatic carcinoma

Suspicious for medullary carcinoma

Suspicious for lymphoma

Suspicious for papillary thyroid carcinoma

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