Small cell carcinoma of the urinary bladder: a case report.
1) Scibetta N. 2)Unti E.
U.O.C. Di Anatomia ed Istologia Patologica A.R.N.A.S. Ospedali Civico e G. di Cristina, Palermo
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
OBJECTIVES
METHODS
Primary small cell carcinoma (SCC) of the
urinary bladder is very rare and shows
aggressive biological behavior and poorer
prognosis than transitional cell carcinoma
(TCC); 50% of them have areas of TCC.
The authors reports herein a case of SCC
of the urinary bladder with emphasis on
immunohistochemistry and histogenesis.
The patient was an 79 year-old man who
presented hematuria for 2 months.
Cystoscopy revealed an ulcerated solid
lesion at dome, 5 cm in the greatest
dimension.The examination of urinary
citology specimen, prepared using
cytocentrifuge technique and stained with
May-Grunwald-Giemsa, Papanicolau and
hematoxylin and eosin methods showed
many small hyperchromatical cells similar
lymphocites, mostly isolated or formed
small groups. Focal molding was also
noted in clusters. The cytomorphological
pattern was interpreted as small and blue
round cell tumor, but differential diagnosis
was difficult. A bladder biopsy were
performed. The patient underwent
cystoprostatectomy.
RESULTS
Microscopically the tumor seemed to have invaded through the muscolaris propria into
the adjacent fat. The bladder tumor is SCC in about 90% and TCC high grade (HG) in
about 10% of the tumor. The SCC consisting of small cells with hyperchromatic nuclei,
inconspicuous nucleoli, molded nuclei, scant cytoplasm. The TCC consisting in HG
neoplasm. In addition to histological features, immunohistochemical stain were
performed and the tumor cells of the SCC component were positive for synaptophysin,
chromogranin, NSE, CD56, CAM5.2, CKAE1/AE3, CK8, CK18, negative for p63, TTF1,
CK7, CK20, CD45, CK19, CK14, CK5/6, CK34BE12, CD117, PDGFRA, whereas the HG
TCC stained selectively for CK7 and CK20. There were 4 out of 14 bilateral lymph-nodes
involved only by the TCC.
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
Light microscopic examination shows small hyperchromatical tumor cell sheets invading
through the muscolaris propria into the adjacent fat
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
High grade urothelial carcinoma
High grade urothelial carcinoma with active mitosis
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
The right half of the section is small cell carcinoma component of the bladder tumor. The left
half of the section is the high grade urothelial carcinoma
The small cell carcinoma component demonstrated synaptophysin positivity. The urothelial
component is negative
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
Small cell carcinoma component: positivity for CD56
The high grade urothelial carcinoma component of the bladder tumor demonstrated CK 7
positivity. The small cell carcinoma component is negative.
Scibetta N., Unti E.
U.O.C. di Anatomia ed Istologia Patologica, A.R.N.A.S. Ospedali Civico e G. di Cristina,
Palermo
Lymph nodes involved by the urothelial component, positive for CK 7
CONCLUSIONS
Malignant trasformation of neuroendocrine cells
demonstrated in normal bladder and a unified concept of
histogenesis of bladder cancer with a common origin from
a multipotent mucosal stem cell are proposed. In our case
a mixed SCC and TCC, with only lymph node metastases
by TCC, and the expression of cytokeratin CAM5.2 in the
small cell component supports the hypotesis of urotelial
origin of SCC (metaplastic theory). Future molecular
studies may delineate the relationship and, thus,
pathogenesis of various form of bladder cancer may allow
investigators to develop targeted therapy.
References
1)Tadashi Terada, Small cell carcinoma of the urinary bladder,
Int JClinExp Pathol.2012;5(6):596-600.
2)Donna E Hansel, Zhongfa Zhang, David Petillo and Bin T
Teh, Gene profiling suggests a common evolution of bladder
cancer subtypes, BMC Medical Genomics 2013 Oct 17;6:42.