Pitfalls in the diagnosis of herpes simplex infection in respiratory cytology.
OBJECTIVE
To evaluate the prevalence and potential pitfalls in making an accurate diagnosis of respiratory herpetic infection.


METHODS
Eighteen cases with the diagnosis of herpes simplex virus (HSV) infection were identified from a total of 7,501 (0.24%) respiratory specimens. All cases were evaluated for classic cytomorphologic features of HSV infection and associated cytologic findings. The parameters studied included number of cells with HSV cytopathic effect, intranuclear inclusions, multinucleation, presence of atypical squamous cells, reparative changes, presence and degree of inflammation and associated obscuring factors.


RESULTS
Only a minority of cases (28%) had numerous cells with classic viral cytopathic change. Four (22%) of 18 cases showed atypical squamous cells, and 5 (28%) revealed reparative changes. The majority of the cases were associated with inflammation, which was severe in 4 cases (22%). Blood and degenerative changes obscured the cytologic findings in 3 cases (17%). One case showed a necrotic background.


CONCLUSIONS
Due to the low prevalence of HSV infection in respiratory cytology, a high index of suspicion is necessary for an HSV diagnosis. Pitfalls for a false negative diagnosis include limited number of cells with viral cytopathic change, only mononuclear cells with viral changes and obscuring inflammation or blood. Pitfalls for a false positive diagnosis of malignancy include atypical keratinized squamous cells, atypical repair, cellular degeneration and necrotic background.
Lapkus
Odetta
O
Department of Pathology, Allegheny General Hospital, Pittsburgh, Pennsylvania 15212, USA.
Elsheikh
Tark M
TM
Ujevich
Beth A
BA
Liu
Yulin L
YL
Silverman
Jan F
JF
D001982:Bronchial Diseases / Q000175:diagnosis* / Q000821:virology; D015897:Comorbidity; D003951:Diagnostic Errors; D006561:Herpes Simplex / Q000175:diagnosis* / Q000821:virology; D006769:Hospitals, General; D006801:Humans; D007196:Indiana / Q000453:epidemiology; D012141:Respiratory Tract Infections / Q000175:diagnosis* / Q000821:virology