Australian Society of CytologyCase of the Month
June 2003 - Answer and Discussion
Herpes virus infection
Answer
The sputum preparation has a florid mixed inflammatory cell infiltrate and debris in the background. Lymphocytes are prominent in all of the prepared slides. There are cells that present with either single or multiple enlarged nuclei and exhibit prominent nuclear moulding. The chromatin marginates beneath the nuclear envelope, which results in a thickened nuclear envelope and a ground-glass appearance in the remainder of the nucleus. Intranuclear (Cowdry type A) viral inclusions surrounded by a pale halo are commonly observed. Intracytoplasmic inclusions are not seen.
Discussion
Herpes virus (simplex or zoster) cannot be distinguished microscopically. Definitive viral diagnosis is confirmed by viral culture and enzyme immunoassay techniques. In lung specimens it is common to observe epithelial repair and prominent inflammatory cell infiltrate resulting from respiratory infection.
This particular case required further assessment as the viral cultures and enzyme immunoassay investigations to confirm the diagnosis in the lung all returned with negative results. Clinical follow-up discovered an immunocompromised patient undergoing treatment for leukaemia who presented with multiple fresh cold sores around the mouth. It was concluded that the pathogenesis of the infection was in fact contamination from the mouth/oesophagus rather than the lung. Contamination of sputum samples with cells from the upper gastro-intestinal tract need to be considered when evaluating sputum for respiratory pathology.
References:
- Bibbo, M 'Comprehensive Cytopathology', W B Saunders Company 1991.
- De May, R 'The Art and Science of Cytopathology', ASCP 1996
