TY - JOUR
T1 - Cytomorphology of follicular dendritic cell sarcoma
T2 - a report of 7 cases with an emphasis on the diagnostic challenges
AU - Weimholt, Cody
AU - Jalaly, Jalal B.
AU - Bailey, Cedric
N1 - Publisher Copyright:
© 2023 American Society of Cytopathology
PY - 2023/5/1
Y1 - 2023/5/1
N2 - Background: Follicular dendritic cell sarcoma is a malignant neoplasm derived from germinal center follicular dendritic cells, which both share a characteristic immunophenotype (namely CD21, CD23, and CD35). Cytomorphologic descriptions are few, consisting of only 26 prior cases from 24 publications. Identification by cytologic means appears challenging as the majority of previous reports disclose an erroneous or indeterminate initial cytologic diagnosis. Herein, we present the largest cytology series to date with the aim of expanding upon this small body of literature and discuss possible factors resulting in misinterpretation. Materials and methods: A retrospective search was conducted from 2 academic medical centers to identify histologically confirmed cases of follicular dendritic cell sarcoma with an associated cytologic component. Clinicopathologic data were tabulated and a comparative analysis of cytomorphologic and immunohistochemical features was performed. Results: Seven separate cases were identified. All cases showed cohesive tumor cells with a characteristic voluminous, ill-defined cytoplasm with interconnecting fibrillary processes and intimately admixed mature lymphocytes. Features were maintained across various cytologic preparations, including conventional smear, liquid-based cytology, and touch imprint. Unusual immunohistochemical profiles were noted in a subset of cases. Conclusions: Cytomorphology is highly conserved across cases and preparations; however, a propensity for aberrant immunoexpression may contribute to diagnostic errors. Cytomorphologic features, supported by immunohistochemistry, suggest fine-needle aspiration as a reasonable diagnostic modality. Tumors with these features should include CD21, CD23, and/or CD35 in the workup.
AB - Background: Follicular dendritic cell sarcoma is a malignant neoplasm derived from germinal center follicular dendritic cells, which both share a characteristic immunophenotype (namely CD21, CD23, and CD35). Cytomorphologic descriptions are few, consisting of only 26 prior cases from 24 publications. Identification by cytologic means appears challenging as the majority of previous reports disclose an erroneous or indeterminate initial cytologic diagnosis. Herein, we present the largest cytology series to date with the aim of expanding upon this small body of literature and discuss possible factors resulting in misinterpretation. Materials and methods: A retrospective search was conducted from 2 academic medical centers to identify histologically confirmed cases of follicular dendritic cell sarcoma with an associated cytologic component. Clinicopathologic data were tabulated and a comparative analysis of cytomorphologic and immunohistochemical features was performed. Results: Seven separate cases were identified. All cases showed cohesive tumor cells with a characteristic voluminous, ill-defined cytoplasm with interconnecting fibrillary processes and intimately admixed mature lymphocytes. Features were maintained across various cytologic preparations, including conventional smear, liquid-based cytology, and touch imprint. Unusual immunohistochemical profiles were noted in a subset of cases. Conclusions: Cytomorphology is highly conserved across cases and preparations; however, a propensity for aberrant immunoexpression may contribute to diagnostic errors. Cytomorphologic features, supported by immunohistochemistry, suggest fine-needle aspiration as a reasonable diagnostic modality. Tumors with these features should include CD21, CD23, and/or CD35 in the workup.
KW - Case series
KW - Cytology
KW - Cytomorphology
KW - Fine-needle aspiration biopsy
KW - Follicular dendritic cell sarcoma
UR - http://www.scopus.com/inward/record.url?scp=85146891992&partnerID=8YFLogxK
U2 - 10.1016/j.jasc.2023.01.002
DO - 10.1016/j.jasc.2023.01.002
M3 - Article
C2 - 36702737
AN - SCOPUS:85146891992
SN - 2213-2945
VL - 12
SP - 229
EP - 238
JO - Journal of the American Society of Cytopathology
JF - Journal of the American Society of Cytopathology
IS - 3
ER -