Fine needle aspiration cytology of IgG4-related disease: A potential diagnostic pitfall?
BACKGROUND
IgG4-related disease (IgG4-RD) is a tumefactive fibro-inflammatory lesion that can affect any organ system in the body. Till date, no cytological data on IgG4-RD are available and this is the first study depicting the cytopathology features of IgG4-RD.


OBJECTIVE
To describe the cytopathological features and potential diagnostic errors of IgG4-RD.


METHODS
The cytological features of 10 histopathology proven IgG4-RD cases (11 samples) were retrospectively reviewed along with corresponding histopathology.


RESULTS
The cellularity of the cytology smears was low (36.4%) to moderate (45.4%) to high (18.1%). The low cellularity correlated well with the pattern C in histopathology (predominant fibrosis pattern). The non-epithelial background showed a preponderance of lymphocytes along with polymorphs and spindle-shaped fibroblasts. Most of these cases showed the presence of plasma cells and eosinophils. Epithelial atypia was seen in 18.2% cases.


CONCLUSIONS
The causes of misdiagnosis were low cellularity, epithelial atypia, and non-representative background. The important diagnostic clues to suspect a diagnosis of IgG4-RD include low cellularity despite adequate effort, inflammatory background rich in lymphocytes and spindle cells admixed with a few plasma cells and eosinophils along with radiological features and raised serum IgG4 Diagn. Cytopathol. 2017;45:14-21. © 2016 Wiley Periodicals, Inc.
Department of Pathology, PGIMER, Chandigarh, India.
Rajwant
R
Kaur
Department of Pathology, PGIMER, Chandigarh, India.
Suvradeep
S
Mitra
Department of Cytopathology and Gynecological Pathology, PGIMER, Chandigarh, India.
Arvind
A
Rajwanshi
Department of Histopathology, PGIMER, Chandigarh, India.
Ashim
A
Das
Department of Histopathology, PGIMER, Chandigarh, India.
Uma
U
Nahar Saikia
Department of Cytopathology and Gynecological Pathology, PGIMER, Chandigarh, India.
Pranab
P
Dey
D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000276:immunology / Q000473:pathology*; D044963:Biopsy, Fine-Needle / Q000592:standards; D002648:Child; D003951:Diagnostic Errors; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D010950:Plasma Cells / Q000473:pathology*
D007074:Immunoglobulin G
IgG4; cytology; pitfall