Primary squamous cell carcinoma of the renal collecting system is a very
rare entity. The incidence of renal squamous cell carcinoma among malignant
renal tumors ranged widely from 0.5% to 8% in the previous reports [5
general, these tumors are highly aggressive and are at high stage when
detected and can be expected to have a poor clinical course.
The lack of characteristic presentation like hematuria, pain and palpable
mass causes delay in diagnosis. Most of the detected tumors are histologically
high grade, 84% of the tumors were locally advanced or metastatic .
Squamous cell carcinoma of the renal pelvis is often associated with phenacetin
consumption, chronic renal calculi or infection. The incidence of co-existing
urinary stone was reported in a wide range between 18%  and 100% .
Squamous metaplasia invades mucosa adjacent to the carcinoma in 17% to
33% of the patients . Whether the occurrence of squamous metaplasia is due
to the presence of the calculus that leads ultimately to the development of
carcinoma or existence of squamous cell carcinoma causes the formation of
calculus is not clear yet. This dilemma is particularly valid for the co-existence
of the tumor and calculus at the renal pelvis. As renal squamous cell carcinoma
is frequently associated with infected staghorn calculi existing for a long
duration, it is recommended for the patients with renal stone disease who dont
need intervention or patients under extracorporeal shock wave lithotripsy
treatment or patients with non-functioning kidney due to stone disease to be
carefully examined with imaging modalities .
The tumor can be documented by conventional radiological imaging
modalities. Filling defects or obstructive lesions in the renal pelvis by
intravenous/retrograde urography or detection of a solid mass by
ultrasonography can be the signs of the tumor . Tomographic imaging
reveals these findings more specifically [10,10].
Recently in a retrospective study of Lee et al , 15 patients with squamous
cell carcinoma of the kidney were classified into two groups according to
localisation of the tumors as central and peripheral type. They stated that the
central renal squamous cell carcinoma presents more intraluminal components
and is usually associated with lymph node metastasis whereas peripheral renal
squamous cell carcinoma presents with prominent renal parenchymal
thickening and might invade the perirenal fat tissue before lymph node or
distant metastasis could be identified. The survival of patients with central renal
squamous cell carcinoma was reported to be significantly shorter than those
with peripheral renal squamous cell carcinoma.
In the report of Nativ et al , patients with renal squamous cell carcinoma
were divided into three groups on the basis of tumor staging criterias outlined
by Peterson . Nativ et al reported that patients with locally invasive renal
squamous cell carcinomas had 1 and 2 year-survival rates of 33% and 22%, respectively. They have also reported that the treatment modalities like
nephrectomy, nephroureterectomy, adjuvant radiotherapy or chemotherapy,
irrespective of tumor stage, did not affect the survival of the patients.
The current primary treatment of renal squamous cell carcinoma is
nephroureterectomy. If metastasis develops, adjuvant chemotherapy or
irradiation has little effect on the unfavourable prognosis .
The case that we mention here is consistent with the peripheral type renal
squamous cell carcinoma as reported by Lee et al . The tumor was locally
advanced like most of the tumors in the literature. The co-existence of renal
calculus and renal squamous cell carcinoma was also present in this case.
Patients with renal stone disease who dont need intervention or patients under
extracorporeal shock wave lithotripsy treatment or patients with non-functioning
kidney due to stone disease must be carefully examined with imaging
modalities and by this way the early detection of the tumor may provide a better
outcome for the patients.
Despite the tumor of our patient has invaded the fascia of Gerota, we are in
an expectation of a better survival with respect to the central type renal
squamous cell carcinoma. We decided to follow-up the patient until the
evidence of metastatic disease would be demonstrated. We are planning to
start a combination chemotherapy including methotrexate, cisplatin and
bleomycin as reported by Corral et al  recently if the signs of metastatic
disease are revealed. Corral reported a high but short lived overall response
rate with this chemotherapy regimen.