A stepwise approach to fine needle aspiration cytology of lymph nodes

Abstract

The cytological diagnosis of lymph node lesions is extremely challenging because of the diverse diseases that cause lymph node enlargement, including both benign and malignant or metastatic lymphoid lesions. Furthermore, the cytological findings of different lesions often resemble one another. A stepwise diagnostic approach is essential for a comprehensive diagnosis that combines: clinical findings, including age, sex, site, multiplicity, and ultrasonography findings; low-power reactive, metastatic, and lymphoma patterns; high-power population patterns, including two populations of continuous range, small monotonous pattern and large monotonous pattern; and disease-specific diagnostic clues including granulomas and lymphoglandular granules. It is also important to remember the histological features of each diagnostic category that are common in lymph node cytology and to compare them with cytological findings. It is also essential to identify a few categories of diagnostic pitfalls that often resemble lymphomas and easily lead to misdiagnosis, particularly in malignant small round cell tumors, poorly differentiated squamous cell carcinomas, and nasopharyngeal undifferentiated carcinoma. Herein, we review a stepwise approach for fine needle aspiration cytology of lymphoid diseases and suggest a diagnostic algorithm that uses this approach and the Sydney classification system.

Comment on “A stepwise approach to fine needle aspiration cytology of lymph nodes”

“…For this purpose, a recent experience on LN-FNAC digital slides has been performed producing quite encouraging results [ 8 ]. In conclusion we think that the algorithm proposed by Chong et al [ 1 ] matches with the Sydney system which will be reproduced in five diagnostic categories and two diagnostic levels also by the near to be published WHO Reporting System for Lymph Node, Spleen, and Thymus Cytopathology .…”

“…We read with great interest the article “A stepwise approach to fine needle aspiration cytology of lymph nodes” by Chong et al [ 1 ], recently published in J Pathol Transl Med . The Authors proposed a morphological stepwise algorithm, separate but complementary to the Sydney system, for the cytological diagnosis of lymphadenopathies [ 2 ].…”

“…Moreover, repetition of LN-FNAC in AUS-ALUS cases, after six-eight weeks may show dramatically changed cytological features in case of reactive hyperplasia. The authors [ 1 ] also state that “the L3 category, which includes AUS and ALUS, is a good example. It is often quite challenging to discriminate a certain lesion as lymphoid or epithelial in origin” and that the Sydney System includes “cases in which the FNAC features favor certain diseases, the cases should be described specifically as “AUS, favor poorly differentiated carcinoma,” This sentence is not reported in the Sydney system text in which suspicious lymphoma and metastases are included in the category suspicious, which has a higher ROM and different clinical implications than the atypical category.…”

Response to comment on “A stepwise approach to fine needle aspiration cytology of lymph nodes”

“…We read Caputo et al’s letter [ 1 ] regarding our recently published review, “A Stepwise Approach to Fine Needle Aspiration Cytology of Lymph Nodes,” with great interest and we really appreciate to their keen observation and critique to our review [ 2 ]. Their critique of our publication focuses on three primary issues: (1) The Sydney system’s strong recommendation for reporting the nosologic entity’s nature (lymphoid/metastatic) [ 3 ].…”

“…10’s diagnostic algorithm, we referenced “sufficient features for malignancy,” intending to encompass all feasible test findings, including morphology, immunocytology, and molecular tests. This was not explicitly stated, but it was implied [ 2 ].…”