Rare cancers of the bladder

Found rare tumors that arise in the bladder fall naturally into two groups: rare histologies and tumor urothelial origin nonurothelial. Our discussion follows these lines, and took the unusual urothelial cancer in the first place, since these are by far the most common and clinically important. Most of what is called transitional cell carcinoma, about 80%, in fact, low histological grade and reflects mainly hyperplastic process. This process typically results in the papillary architecture of the mass thickness of cell proliferation, but not invasive. These injuries, known as "Ta", tend to recur and may progress to dysplasia and invasion in 15 to 20% of patients. However, for the most part, these tumors are more similar to polyps’ true carcinomas. An averlapping but definite pattern can be recognized in the remaining 20% of cases. In this group, high histological grade dysplasia and invasion are hallmarks.

These "non-papillary" cancers are the cause of most mortality, and show a significant range of histomorphology. In the end, they are so different from transitional cell carcinoma (TCC) that called for an alternative taxonomy. Although very rare as "pure" variant, the fact remains that about one third of non-papillary bladder cancers exhibit at least focal areas of unusual histologies discussed below. Therefore, in practice, there is considerable uncertainty about which of the cases showing lesser degrees of histological variant is considered really outside the normal spectrum of TCC, and should be classified as distinct entities.

Carcinoid tumors in the kidney

Primary renal carcinoid is extremely rare, well-differentiated neuroendocrine tumor of unknown etiology. The origin of this tumor is still unclear as neuroendocrine cells are not normally present in the renal parenchyma. There have been 50 cases reported in the literature, with a strong partnership with the horseshoe kidney in approximately 20% of cases. The relative risk for a person with horseshoe kidney to develop this tumor is estimated at 82 times the general population. Was first reported by Resnick in 1966 in a patient with carcinoid syndrome, however, most organ-confined tumors do not produce carcinoid syndrome, which resembles carcinoids in other organ systems.

Pathology

Macroscopically, it presents as a solitary well-circumscribed, moderately firm tumor with a lumpy appearance. The color is variable; the appearance is consistent with variable focal hemorrhage and calcification. The histopathologic features appear similar to carcinoid tumors in other organ systems. The cells are uniform in size and arranged in a trabecular pattern. Have small nuclei with "salt and pepper" chromatin and eosinophilic cytoplasm. Immunohistochemical staining is positive for chromogranin, neuron-specific enolase, and keratin. Variable positivity for serotonin, pancreatic polypeptide, prostatic acid phosphatase, and vasoactive intestinal polypeptide have been reported.

Clinical Presentation

Most patients present with an asymptomatic mass, however, can also present with abdominal pain, mass, or hematuria. Alternative source differential diagnosis is indicated when a lesion is found in the kidney, due to the rarity of primary renal carcinoid. carcinoid symptoms are present in less than 10% of patients at presentation.

The median age at diagnosis is 50 years, without sex predilection. The TC is presented as a circumscribed solid mass with occasional calcification or cystic changes. Some authorities have suggested that an octreotide scan can contribute to accurate staging
diagnosis.

Treatment and Prognosis

Because of the rarity of the disease, clinical outcome is difficult to predict. This is also complicated by the fact that a significant proportion of patients with metastatic disease have prolonged survival. Complete excision of localized disease in the kidney seems to have good long-term results, with reports available are limited. Carcinoid tumors arising in horseshoe kidneys tend to have a more indolent course.

Carcinoid crisis secondary to the release of vasoactive substances may occur with the biopsy or surgical resection of the tumor and can be managed with somatostatin. In patients with a solitary metastasis, especially in the liver, it would be appropriate to consider resection of primary tumor with metastasis, due to the lack of effective systemic treatment options. Radiation is effective for short-term relief. The scant information on therapy for metastatic renal carcinoid is available. In patients with carcinoid syndrome, control of symptoms with somatostatin or octreotide analogs as possible.

For people with metastatic disease, systemic treatment options are based on clinical trials in patients with gastrointestinal carcinoid tumors. Interferon produces tumor regression (15%) and biochemical responses in patients with metastatic disease. Combination chemotherapy is of limited value. In a cooperative oncology group of the East (ECOG) trial, 118 patients with metastatic carcinoid tumor were randomized to treatment with streptozotocin in combination with cyclophosphamide or 5-fluorouracil (5-FU). Objective response rates among evaluable patients treated with the combination of 5-FU was 33% and the combination of cyclophosphamide 26%, with substantial toxicity in both regimens.

Carcinoma of the Bellini collecting duct in kidney tumors

CDC is a rare tumor cells derived from renal collecting ducts of Bellini, and has less than 1% renal malignancies. Reported by Mancilla-Jimenez et al. in its report on papillary tumors, the examination renal tissue distant from the tumor to appear, in some cases, atypical hyperplastic changes of collecting tubules.

This raised the possibility that some papillary tumors arose from distal tubular pithelium. Fleming and Lewi ago describe the detailed features of the CDC as pathological entity based on several case reports.

Pathology
This tumor is characterized by a core location, with a size ranging from 2 to 12 cm, the appearance of firm white-gray and irregular infiltrative edge. Grows radially from the renal hilum to invade the renal cortex, renal cap Sule, and the renal sinus. Histologically, an irregular pattern of growth embedded in a desmoplastic tubulopapillary stroma. The tubules are lined with cells with eosinophilic cytoplasm nail scarce. The cells display high-grade nuclei with brisk mitotic activity, and prominent nucleoli. Sometimes sarcomatoid changes or mucin can be seen. Molecular events and cytogenetic changes that contribute are not well characterized, and a different pattern has yet emerged. The immunohistochemical profile is variable, with generally positive for phytoagglutinins and high molecular weight cytokeratin, with coexpression of vimentin and negative for CD10 and villi.


Clinical Presentation
It is a very aggressive tumor, usually presenting at an advanced stage, with gross hematuria, abdominal pain / back pain and a flank mass. At diagnosis, they often have metastatic disease in the lung, liver, lymph nodes, bone, or adrenal gland. It is more common in men (ratio of about 2: 1) with a wide range of age groups (13-83 years with an
average 55 years). Computed tomography (CT), this tumor appears as a central mass arising infiltrating the preservation of the renal contour and minimal contrast enhancement. Patients may have generalized inflammatory symptoms secondary to the release of cytokines of the tumor and the inflammatory reaction associated with the tumor.

Treatment and Prognosis
The diagnosis of CDC is usually done after the operation, and unlike other radiological RCC is difficult and there is a low preoperative suspicion in view of the rarity of the disease. The prognosis is generally very poor with most patients with distant metastases developing rapidly, with a median survival of 22 months.

The role of nephrectomy has been the subject of debate due to frequent metastasis to the presentation. Radical nephrectomy in the context of metastasis CDC appears to be useful only for palliation. Based on the pathological, immunohistochemical and cytogenetic
similarity with urothelial (CTP), compared with conventional carcinomas clear cell RCC, the preferred approach in treatment of metastatic disease with chemotherapy has been in place for immunotherapy.

In the largest series reported Dimopoulos et al. subsequently reported the MD Anderson Cancer Center experience involving 12 patients with CDC treated from 1980-90. Seven of eight patients with metastatic disease were treated with different combinations of chemotherapy with doxorubicin and cisplatin, methotrexate; vinblastine (MVAC) regimen is the most common. Only one patient achieved a minor response lasting 5 months. Six patients were treated with a combination of interleukin-2 and IFN-α with a response in a patient. Peyromaure et al. reported two complete responses with cisplatin and gemcitabine combination chemotherapy, which lasted 9 and 27 months.

Radiotherapy in this series appeared to have minimal benefit for local recurrence. Chao et al. a review noted that some patients with regional nodal disease without distant etastases have long-term disease-free survival with adjuvant therapy.

While the overall benefit of chemotherapy or immunotherapy appears to be minimal, there seems to be a select group of patients who will benefit of these approaches. Cisplatin-Gemcitabine has significant activity with a favorable toxicity profile in urothelial cancers and has caused some significant response in patients with CDC. Thus access to the system to some extent, since the preferred first-line chemotherapy simply because it is less toxic than MVAC regimen, and no other major series of chemotherapy for collecting duct tumors has apparently better results.

Papillary adenoma Tumors of the Kidney

Historically, the adenomas were recognized as lesions less than 3 cm based on the work of Bell. This was later modified identified in 1970 by Murphy and Mostofi who felt that the histological differentiation of Aden carcinomas adenomas was true possible. Renal papillary adenomas are small, discrete, and arise from renal tubular epithelium. In autopsy studies, increasing in frequency with age (7-40%).

Pathology
In the most recent WHO classification, papillary adenomas are less than 5 mm in diameter with a low nuclear grade. They appear as pale yellow, gray, well circumscribed nodules, usually below the renal capsule in the renal cortex. They usually not encapsulated, however, some have thin pseudo capsule. In microscopic examination, which have tubular architecture, papillary or tubular-like papillary renal cell carcinoma. The cells have scant cytoplasm, round to oval nuclei and have high nuclear grade (Fuhrman nuclear grade 3 or 4). Cytogenetics Features include trisomy (chromosome 7 and 17) and the loss of similarity chromosome. The And in this tumor with papillary renal cell carcinoma has led to the view that it may represent a precursor lesion for CRC.

Clinical presentation and treatment
Most of these lesions are discovered accidentally. They tend to occur more frequently in patients with underlying kidney disease related to atherosclerosis, scarring, acquired renal cystic disease secondary to hemodialysis, and other malignancy prevailing conditions of the kidney.

With small tumors incidentally detected increasingly during radiological procedures, the current view is to consider them all as probable early cancer to a clear marker of benignity is discovered. Renal tumors with diameters of 0.5 to 2 cm often behave sluggish, although the biologic behavior is difficult to determine, so that tumors less than 2 cm

They are sometimes called "renal epithelial tumors of uncertain malignant potential, and observed for progression, while Larger tumors may require surgical removal, depending on the clinical scenario. There is no defined role for radiation therapy or chemotherapy in the treatment of renal papillomas.

MOLECULAR DIAGNOSTIC TECHNIQUES IN RENAL NEOPLASMS in Tumors of the Kidney

Tumors of the kidney account for about 3% of adult malignancies, with an incidence of approximately 36 000 new cases/year in the United States. The first classification of renal tumors was proposed by Konig in 1826. This classification was made on the basis of gross morphologic characteristics. Extensive study of renal neoplasms in the last couple of decades has led to a standardized nomenclature by the European and American authorities. 

The 2004 WHO classification, which includes nearly 50 distinct entities, is based on a combination of immunohistochemistry, histology, and clinical and genetic features that are widely accepted and relatively reproducible. Several large series have shown this classification to have prognostic significance and that it is
relevant to diagnosis by fine needle aspiration techniques. It is anticipated this current classification system will be reassessed in 5 years

MOLECULAR DIAGNOSTIC TECHNIQUES IN RENAL NEOPLASMS
 

The application of molecular and cytogenetic techniques has resulted in improved understanding of these tumors. Routine use of these techniques for diagnosis is cumber some, although they serve as useful adjuncts in selected cases. In the forefront among these technologies are comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH), allelic loss analysis, classical cytogenetics, and karyotyping. The von Hippel-Lindau tumor suppressor gene resides in the short arm of chromosome and is commonly inactivated by gene mutation or promoter hypermethylation in sporadic clear cell RCC.

It is also the causative gene for the von Hippel-Lindau syndrome.Papillary RCC, chromophobic RCC, carcinoma of the collecting ducts of Bellini, metanephric adenomas, and renal oncocytomas have also exhibited characteristic chromosomal anomalies.

Recently, RCC associated with chromosomal translocation involving TFE3 gene on Xp11.2 has been described as a distinct clinicopathological entity. Differentiating the various histological subtypes of renal tumors is crucial, since they differ in their prognosis and therapeutic response to treatment. Definitive diagnosis based on H&E morphology is possible in the majority of cases. In the minority circumstances where distinction becomes difficult, immunohistochemistry and other molecular techniques are being increasingly relied upon to make the distinction.

Renal cell carcinoma marker (RCC Ma) is a monoclonal antibody against the proximal tubular brush border antigen, which is relatively specific for renal neoplasms that originate from the proximal renal tubules including clear and papillary RCC, despite a rather low sensitivity.The anti body is positive in nearly 80% of clear cell and papillary RCC, is variably expressed in chromophobe RCC, and is absent in oncocytomas and CDCs. CD10 is another marker that helps in the differential diagnosis, by being expressed in clear cell and papillary RCC, and absent in chromophobe RCC and oncocytomas.

Vimentin is variably expressed in clear cell and papillary RCC and is absent in chromophobe RCC and oncocytomas. Cytokeratins represent a widely used diagnostic immunohistochemical marker in differentiating renal tumors. Cytokeratin 7 (CK7) is strongly positive in most chromophobe RCC, absent in clear cell RCC, and variably expressed in oncocytomas. Routine metaphase cytogenetics, performed on cultured tumor cells, has been used to identify cytogenetic changes associated with each RCC histological subtypes. Using specific probe sets, FISH can be used to identify those RCC with characteristic chromosomal alterations