Diagnostic value of GLUT‐1 immunoreactivity to distinguish benign from malignant cystic squamous lesions of the head and neck in fine‐needle aspiration biopsy material

Abstract

The distinction of cystic squamous-cell carcinoma (SCC) from benign cystic squamous lesions (BCSLs) of the head and neck can be problematic on fine-needle aspiration biopsy (FNAB) material, particularly when BCSLs display epithelial reactive atypia or when SCC is well differentiated. Glucose transporter 1 (GLUT-1), a facilitative cell surface glucose transport protein, is aberrantly expressed in many cancers including oral and hypopharyngeal SCC. We evaluated the expression of GLUT-1 by immunochemistry on FNAB material to determine its value in distinguishing cystic SCC from BCSL of the head and neck. A 5-yr retrospective review of all head and neck cystic squamous lesions having FNAB specimens with cell block material, radiological studies, and histological confirmation was performed at our institution. Cell block material from 24 cystic squamous lesions, including 8 (33%) BCSL (7 branchial cleft cysts and 1 thyroglossal duct cyst[TDC]) and 16 (67%) metastatic SCCs with cystic/liquefactive degeneration, was retrieved and immunostained with anti-GLUT-1. GLUT-1 expression was considered positive when at least 10% of squamous cells exhibited distinct cell membrane reactivity. Positive GLUT-1 immunostaining was detected in all 16 SCCs and in none of the 8 BCSLs. In the carcinoma cases, the majority of malignant cells exhibited GLUT-1 reactivity; only a minor population of well-differentiated SCC cells displaying keratinization and arranged as squamous pearls did not express GLUT-1. GLUT-1 expression in cell block material can help to distinguish cystic SCCs from BCSLs of the head and neck. In conjunction with clinical and radiological correlation, GLUT-1 immunoreactivity can be an important diagnostic aid when the cytological findings are ambiguous.

The utility of GLUT-1 immunolocalization in cell blocks

“…Although false-positive immunoreactivity for GLUT-1 in benign squamous lesions of the head and neck was not noted in our study or in a previous study, 8 GLUT-1 has been detected in benign proliferative skin lesions. 20 Therefore, caution is warranted in using GLUT-1 immunostaining as the sole criterion for a diagnosis of malignancy.…”

“…19 In a recent study, Weiner et al demonstrated that immunolocalization of GLUT-1 is a useful diagnostic tool to distinguish between benign and malignant squamous cystic lesions of head and neck. 8 Results from our study also suggest that GLUT-1 immunostaining is useful as an ancillary marker in cell-block preparations in the differential diagnosis of cystic squamous lesions of the head and neck. In our study, GLUT-1 immunostaining was detected in not only 100% of cases where the cytologic diagnosis of SCC was obvious, but also in 50% of cases where the cytology was equivocal.…”

“…We have demonstrated that none of the 11 benign squamous lesions of the head and neck (confirmed either by tissue or clinical follow-up) stained positively for GLUT-1; however, negative GLUT-1 staining was also observed in 1 case with equivocal cytology but with subsequent histologic diagnosis of SCC. Weiner et al 8 also showed positive GLUT-1 immunostaining in all cases with an unequivocal cytologic diagnosis of SCC and in none of the benign squamous lesions from the head and neck in FNA-derived cell-block material.…”

“…6,7 In a recent study Weiner et al have shown that glucose transporter-1 (GLUT-1) expression in FNA-derived cell-block material is useful in resolving the common diagnostic dilemma of distinguishing benign from malignant squamous lesions of the head and neck. 8 The purpose of present study was to examine the reliability of previously documented usefulness of GLUT-1 immunolocalization of cell-block material in distinguishing benign from malignant squamous lesions of head and neck.…”

Immunohistochemical detection of GLUT-1 can discriminate between reactive mesothelium and malignant mesothelioma

“…25,26 Although a few studies have demonstrated that GLUT-1 is useful for distinguishing RM from metastatic adenocarcinoma in body cavity effusions, 27-29 the study cohorts did not include MPM. Using immunohistochemistry, Godoy et al 16 analyzed coexpression of GLUT-1 and other GLUT isoforms (GLUT-2 to -6 and GLUT-9) in a variety of benign and malignant tumors, and demonstrated that two of four MPMs were positive for GLUT-1.…”