Salivary glands

Cytology

Milan system

Nondiagnostic



Last author update: 24 May 2023
Last staff update: 24 May 2023

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PubMed Search: Salivary glands - nondiagnostic FNA

Jen-Fan Hang, M.D.
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Cite this page: Hang JF. Nondiagnostic. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/salivaryglandsmilannondiagnostic.html. Accessed May 19th, 2024.
Definition / general
Essential features
  • FNA with insufficient amount of lesional cells to provide an informative interpretation (ideally > 60 lesional cells for adequate evaluation)
  • Poorly prepared slides with artifacts (e.g., air drying, obscuring blood and poor staining) that preclude the evaluation of the cellular component
  • Normal nonneoplastic salivary gland elements in the setting of a clinically or radiologically defined mass
  • Nonmucinous cyst fluid without an epithelial component
Terminology
  • Nondiagnostic
  • Nondiagnostic, cystic fluid only for nonmucinous cyst fluid without an epithelial component
Etiology
  • Palpation guidance without ultrasound, inadequate sampling determined by rapid on site evaluation and lesions with cystic, vascular or diffuse nature are significantly associated with nondiagnostic results (Cancer Cytopathol 2022;130:609)
Treatment
Cytology description
  • FNA with < 60 lesional cells, although specific criteria have not been established
  • Poorly prepared slides with artifacts (e.g., air drying, obscuring blood and poor staining) that preclude the evaluation of the cellular component
  • Normal nonneoplastic salivary gland elements in the setting of a clinically or radiologically defined mass
  • Nonmucinous cyst fluid without an epithelial component
  • Exclusion criteria
    • FNA with scant cellularity but significant cytologic atypia → at least atypia of undetermined significance (AUS)
    • Mucinous cyst fluid contents without an epithelial component → atypia of undetermined significance
    • Abundant inflammatory cells without an epithelial component → nonneoplastic
    • Acellular FNA with a matrix component suggestive of a pleomorphic adenoma → neoplasm: benign
  • Reference: Faquin: The Milan System for Reporting Salivary Gland Cytopathology, 1st Edition, 2018
Cytology images

Contributed by Jen-Fan Hang, M.D.

Nonneoplastic acinar cells

Benign skeletal muscle

Cystic fluid only

Sample pathology report
  • Parotid gland, right, fine needle aspiration:
    • Nondiagnostic (see comment)
    • Comment: Insufficient cellularity for diagnosis.

  • Submandibular gland, left, fine needle aspiration:
    • Nondiagnostic (see comment)
    • Nonneoplastic benign salivary gland elements only
    • Comment: The finding of nonneoplastic salivary gland elements only does not explain the presence of a clinically or radiologically defined mass. Repeat fine needle aspiration under radiologic guidance is recommended if clinically indicated.

  • Parotid gland, left, fine needle aspiration:
    • Nondiagnostic (see comment)
    • Comment: Cystic fluid only.
Board review style question #1

A 45 year old woman presents with a 2.8 cm right parotid nodule. Ultrasound demonstrates a well defined nodule with heterogeneous echogenicity. Fine needle aspiration is performed. What is the best diagnosis according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)?

  1. Atypia of undetermined significance
  2. Benign neoplasm, pleomorphic adenoma
  3. Nondiagnostic
  4. Nonneoplastic
Board review style answer #1
C. Nondiagnostic. The presence of normal nonneoplastic salivary gland acinar cells only in the setting of a clinically and radiologically defined mass should be diagnosed as nondiagnostic. The FNA sample is not considered representative of the lesion detected on clinical and radiologic examination. Repeat FNA under radiologic guidance is recommended if clinically indicated.

Comment Here

Reference: Nondiagnostic
Board review style question #2

A 38 year old man presents with a 3.0 cm right parotid mass. Ultrasound demonstrates a mixed solid and cystic tumor. Fine needle aspiration is performed. What is the best diagnosis according to the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC)?

  1. Atypia of undetermined significance, mucinous cystic lesion
  2. Malignant, low grade mucoepidermoid carcinoma
  3. Nondiagnostic, cyst fluid only
  4. Nonneoplastic, compatible with mucocele
Board review style answer #2
A. Atypia of undetermined significance, mucinous cystic lesion. This FNA contains abundant mucin without any epithelial cells. The differential diagnosis includes a benign mucinous cyst; however, a low grade mucoepidermoid carcinoma cannot be excluded. Based on the MSRSGC, the most appropriate diagnosis would be atypia of undetermined significance. Clinical and radiological correlations are needed. Aspiration of a residual mass, if present, may help to achieve a more specific diagnosis.

Comment Here

Reference: Nondiagnostic
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