| RE:
THE ROLE OF SQUAMOUS DIFFERENTIATION IN PATIENTS WITH TRANSITIONAL CELL
CARCINOMA OF THE BLADDER TREATED WITH RADICAL CYSTECTOMY
(
Download pdf )
ALBERTO A. ANTUNES,
LUCIANO J. NESRALLAH, MARCOS F. DALL’OGLIO, CARLOS E. MALUF, CESAR
CAMARA, KATIA R. LEITE, MIGUEL SROUGI
Division
of Urology, University of Sao Paulo Medical School, Sao Paulo, Brazil
and Hospital Sirio Libanes, Sao Paulo, Brazil
Int
Braz J Urol, 33: 339-346, 2007
To the Editor:
Squamous
differentiation is well known to occur in the bladder urothelial carcinoma
and represents the most common form of mixed differentiation (1-5). When
defined by the presence of intercellular bridges and/or keratinization
in urothelial carcinoma, it occurs in 21% of urothelial carcinomas of
the bladder, and in 44% of tumors of the renal pelvis (2-3). Its frequency
increases with grade and stage (2-3). The diagnosis of squamous cell carcinoma
is reserved for pure lesions without any associated urothelial component,
including urothelial carcinoma in situ (5). Tumors with any identifiable
urothelial element are classified as urothelial carcinoma with squamous
differentiation and an estimate of the percentage of squamous component
should be provided (3-5).
The clinical significance of squamous differentiation
remains uncertain, but seems to be an unfavorable prognostic feature in
such patients undergoing radical cystectomy, possibly, because of its
association with high-grade tumors (1-5). This is supported by Antunes
et al. (1). These authors have conducted an interesting study related
to clinical implications of squamous differentiation in urothelial carcinoma
treated by radical surgery. In their study, 22% of tumors had squamous
differentiation, but most importantly, they observed a higher disease
recurrence and mortality in patients having squamous differentiation as
compared with patients without squamous differentiation. Antunes et al.
(1), also found squamous differentiation as independent predictor of survival
in patients with bladder cancer after radical surgery. This study provides
nicely performed evidence on the usefulness of reporting the presence
of squamous differentiation in urothelial carcinoma. Other studies have
emphasized squamous differentiation as predictor of a poor response to
radiation therapy, and possibly also to systemic chemotherapy, although
the controversy still exists on this issues. To avoid some problems related
to the criteria in assessing squamous differentiation, the use of immunohistochemical
technique in addition to appropriated conventional analyses is advised
(2). Cytokeratin 14, caveolin, uroplakins and L1 antigen have been reported
as immunohistochemical markers of squamous differentiation since they
are expressed in urothelial carcinoma and not in squamous differentiation
(2). Finally, the main limitation of the study by Antunes et al. (1) is
the small number of cases entering the analysis; therefore studies on
the issue including larger series might be necessary to confirm the data
by Antunes et al.
References
1. Antunes AA, Nesrallah LJ, Dall’Oglio MF, Maluf CE, Camara C,
Leite KR, Srougi M: The role of squamous differentiation in patients with
transitional cell carcinoma of the bladder treated with radical cystectomy.
Int Braz J Urol. 2007; 33: 339-46.
2. Lopez-Beltran A, Cheng L: Histologic variants of urothelial carcinoma:
differential diagnosis and clinical implications. Hum Pathol. 2006; 37:
1371-88.
3. Lopez-Beltran A, Requena MJ, Alvarez-Kindelan J, Quintero A, Blanca
A, Montironi R: Squamous differentiation in primary urothelial carcinoma
of the urinary tract as seen by MAC387 immunohistochemistry. J Clin Pathol.
2007; 60: 332-4.
4. Emerson RE, Cheng L: Immunohistochemical markers in the evaluation
of tumors of the urinary bladder: a review. Anal Quant Cytol Histol. 2005;
27: 301-16.
5. Lopez-Beltran A, Sauter G, Gasser T: Urothelial Tumors: Infiltrating
Urothelial carcinoma. In: Eble JN SG, Epstein JI, Sesterhenn I (eds).
World Health Organization Classification of Tumors. Pathology and Gentics
of Tumors of the Urinary System and Male Genital Organs. Lyon, IARC Press.
2004.
Dr.
Maria J. Requena
Dr.Antonio Lopez Beltran
Urology Unit (MJR)
Anatomic Pathology Unit (ALB)
Department of Surgery
Cordoba University Medical School
Cordoba, Spain
E-mail: em1lobea@uco.es
|