Deep-seated rectal/anal basaloid carcinoma: useful immunocytochemistry in rare squamous cell carcinoma variants.
OBJECTIVE
To report the cytological aspects of ano-rectal basaloid carcinoma (BC) variant in endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) conventional and liquid-based cytology (LBC), in a series of 10 cases of deep-seated squamous cell carcinomas (SCC), and to discuss the diagnostic difficulties in interpreting the morphology and immunocytochemical findings.


METHODS
Ten cases of EUS-FNA smears and LBC specimens of deep-seated pelvic masses were retrospectively collected from January 2001 to November 2006.


RESULTS
Ten EUS-FNA specimen cases were SCC, eight corresponding to usual SCC and two to BC-variant. Of these two cases, only one was correctly diagnosed by EUS-FNA specimen, whereas in the second case, the initial cytological diagnosis was poorly differentiated adenocarcinoma and the final diagnosis of basaloid carcinoma variant was established on surgical resection. Immunocytochemistry (ICC) using CK7, CK20 and CK34betae12 on FNA specimens confirmed the diagnosis retrospectively.


CONCLUSIONS
The diagnosis of basaloid variant of SCC in a rectal location can be very difficult, both on account of the uncommon location and because of the low specificity of morphological aspects on EUS-FNA smears. The immunocytochemical technique, including a limited spectrum of keratins (CK7, CK20, CK34betae12, and p63) is necessary to avoid this diagnostic pitfall.
Department of Anatomic Pathology, University Paris-Sud 11, Bicêtre University Hospital, AP-HP, Le Kremlin-Bicêtre, France.
M R
MR
Ghigna
K
K
Drak Alsibai
J
J
Porras
L
L
Palazzo
J M
JM
Godchaux
M
M
Fabre
D000328:Adult; D001005:Anus Neoplasms / Q000175:diagnosis / Q000473:pathology; D014408:Biomarkers, Tumor; D044963:Biopsy, Fine-Needle / Q000379:methods; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000473:pathology; D019160:Endosonography / Q000379:methods; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods*; D008875:Middle Aged; D018295:Neoplasms, Basal Cell / Q000175:diagnosis / Q000473:pathology; D012004:Rectal Neoplasms / Q000175:diagnosis / Q000473:pathology; D012189:Retrospective Studies
D014408:Biomarkers, Tumor