Glial fibrillary acidic protein and CD57 immunolocalization in cell block preparations is a useful adjunct in the diagnosis of pleomorphic adenoma.

Abstract

CONTEXT:

The cytologic distinction between pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) can be diagnostically challenging in aspirate smears. Hence a cytologic diagnosis of "atypical cytology" with a differential diagnosis including PA and ACC is occasionally rendered in a subset of salivary gland fine-needle aspirations.

OBJECTIVE:

To evaluate the role of glial fibrillary acidic protein (GFAP) and CD57 expression in cell block material obtained during fine-needle aspiration procedure in differentiating PA from ACC.

DESIGN:

We performed GFAP and CD57 immunostains on formalin-fixed, paraffin-embedded cell block sections of 26 salivary gland fine-needle aspiration cases with the following cytologic diagnoses: (1) PA (10 cases); (2) atypical cytology, cannot exclude ACC (8 cases); and (3) ACC (8 cases).

RESULTS:

All 10 (100%) cases with cytologic diagnoses of PA were positive for GFAP, and 8 (80%) of 10 cases were positive for CD57; tissue follow-up confirmed the diagnosis of PA in all cases. All 8 (100%) cases with cytologic diagnosis of ACC were negative for both GFAP and CD57; tissue follow-up confirmed the diagnoses of ACC in all cases. Of the 8 cases with diagnoses of atypical cytology, 4 (50%) were negative and 4 (50%) were positive for both GFAP and CD57. Subsequent tissue follow-up in these cases revealed 4 cases of ACC (all negative for GFAP and CD57) and 4 cases of PA (all positive for GFAP and CD57).

CONCLUSIONS:

Our results show that positive staining for GFAP and CD57 serves as a useful adjunct for the diagnosis of PA and helps to reduce the uncertainty in challenging cases.

• Authors: Sejal S Shah, Vishal S Chandan, David C Wilbur, Kamal K Khurana
• Journal: Archives of pathology & laboratory medicine (Arch Pathol Lab Med) Vol. 131 Issue 9 Pg. 1373-7 (Sep 2007) ISSN: 1543-2165 [Electronic] United States
• PMID: 17824792 (Publication Type: Journal Article)

Chemical References

• CD57 Antigens
• Glial Fibrillary Acidic Protein

Topics

• Adenoma, Pleomorphic (diagnosis, metabolism, pathology)
• Biopsy, Fine-Needle
• CD57 Antigens (genetics, metabolism)
• Carcinoma, Adenoid Cystic (diagnosis, metabolism, pathology)
• Diagnosis, Differential
• Gene Expression Regulation, Neoplastic
• Glial Fibrillary Acidic Protein (genetics, metabolism)
• Humans
• Paraffin Embedding
• Salivary Gland Neoplasms (diagnosis, metabolism, pathology)
• Salivary Glands (metabolism, pathology)