Micropapillary transitional cell carcinoma of the urinary bladder

Prognostic and therapeutic role of HER2 expression in micropapillary carcinoma of the bladder

Micropapillary carcinoma of the bladder (MPBC) is a variant type of infiltrating urothelial carcinoma, which portends a poor biological behavior in terms of disease stage at first diagnosis and clinical outcome; its peculiar morphology raises issues concerning the ability of tumor detection by imaging techniques and proper biopsy procedure, and the appropriate treatment for non-muscle infiltrating and muscle-infiltrating MPBC remains a matter of debate. On the basis of its established prognostic and therapeutic role in breast and gastro-esophageal cancer in the first instance, the human epidermal growth factor receptor-2 (HER2) has been investigated in selected case series of MPBC over the last 10 years. The aim of the present review was to summarize the existing evidence on HER2 status in MPBC, and to discuss its present and future utility in risk assessment and treatment choice of this uncommon, yet aggressive, disease.

Comprehensive genomic profiling of 295 cases of clinically advanced urothelial carcinoma of the urinary bladder reveals a high frequency of clinically relevant genomic alterations

BACKGROUND

In the current study, the authors present a comprehensive genomic profile (CGP)-based study of advanced urothelial carcinoma (UC) designed to detect clinically relevant genomic alterations (CRGAs).

METHODS

DNA was extracted from 40 µm of formalin-fixed, paraffin-embedded sections from 295 consecutive cases of recurrent/metastatic UC. CGP was performed on hybridization-captured, adaptor ligation-based libraries to a mean coverage depth of 688X for all coding exons of 236 cancer-related genes plus 47 introns from 19 genes frequently rearranged in cancer, using process-matched normal control samples as a reference. CRGAs were defined as GAs linked to drugs on the market or currently under evaluation in mechanism-driven clinical trials.

RESULTS

All 295 patients assessed were classified with high-grade (International Society of Urological Pathology classification) and advanced stage (stage III/IV American Joint Committee on Cancer) disease, and 294 of 295 patients (99.7%) had at least 1 GA on CGP with a mean of 6.4 GAs per UC (61% substitutions/insertions/deletions, 37% copy number alterations, and 2% fusions). Furthermore, 275 patients (93%) had at least 1 CRGA involving 75 individual genes with a mean of 2.6 CRGAs per UC. The most common CRGAs involved cyclin-dependent kinase inhibitor 2A (CDKN2A) (34%), fibroblast growth factor receptor 3 (FGFR3) (21%), phosphatidylinositol 3-kinase catalytic subunit alpha (PIK3CA) (20%), and ERBB2 (17%). FGFR3 GAs were diverse types and included 10% fusions. ERBB2 GAs were equally divided between amplifications and substitutions. ERBB2 substitutions were predominantly within the extracellular domain and were highly enriched in patients with micropapillary UC (38% of 32 cases vs 5% of 263 nonmicropapillary UC cases; P<.0001).

CONCLUSIONS

Using a CGP assay capable of detecting all classes of GA simultaneously, an extraordinarily high frequency of CRGA was identified in a large series of patients with advanced UC. Cancer 2016;122:702-711. © 2015 American Cancer Society.

Expression of RCAS1 correlates with urothelial bladder cancer malignancy

RCAS1 is a protein that participates in regulation of the tumor microenvironment and its immune responses, all in order to evade the immune system. The aim of this study was to analyze RCAS1 expression in urothelial bladder cancer cells (and in fibroblasts and macrophages of the tumor stroma) and its relationship with the histological pattern of malignancy. Eighty-three postcystectomy patients were enrolled. We analyzed the histological maturity (grade), progress (pT stage), tissue invasion type (TIT), nonclassic differentiation number (NDN), and the ability to metastasize (pN). The expression of RCAS1 protein was analyzed by immunohistochemistry. Indicators of histological malignancy were observed solely in association with the RCAS1 expression in cells in the border parts (BPs) of the tumor. Histological malignancy of the tumor, indicated by the pT and pN, and metastasis-free survival time, correlated significantly with RCAS1 expression in tumor neoplastic cells, whereas malignancy determined by grade, TIT, and NDN correlated with RCAS1 expression in fibroblasts and macrophages in the tumor microenvironment. These findings suggest that the increased RCAS1 expression depends on its cellular source and that RCAS1 expression itself is a component of various signaling pathways. The immune escape occurs within the tumor BPs, where the increase in the RCAS1 expression occurs within tumor cells and stromal cells in its microenvironment. We conclude that the histological pattern of tumor malignancy, indicated by grade, TIT, NDN, pT, and pN is a morphological indicator of immune escape.

Micropapillary variant of urothelial carcinoma

Micropapillary carcinoma (MPC) of urinary tract is an uncommon variant of urothelial carcinoma with significant diagnostic and prognostic implications. Though MPC shows characteristic microscopic features, there exists interobserver variability and also it needs to be differentiated from the metastasis from other organs. The prognosis is generally poor, depending on the proportion of the micropapillary component in some reports. Early cystectomy in cases with only lamina propria invasion may be indicated according to recent studies. This review outlines the general features of this entity and briefly comments on the controversies and the recent development.

Urothelial Carcinoma and its Variants

Bladder cancer is the ninth most common cancer worldwide, and the most common malignancy affecting the urinary tract, with approximately 330,000 new cases and more than 130,000 deaths per year. Bladder cancer is primarily attributable to smoking, which accounts for 65% of male and 30% of female cases in some developed countries. Other major risk factors include analgesic abuse, some types of chemotherapy, occupational exposure to chemicals, and in Egypt and some Asian regions, endemic infection with Schistosoma haematobium. Approximately 90% of bladder tumors are classified as urothelial carcinoma (UC), also referred to as transitional cell carcinoma (TCC), and are believed to originate from transformation of the normal urothelium. UCs often exhibit elements of squamous or glandular differentiation. The spectrum of microscopic forms of urothelial carcinoma has been expanded recently to include several histologic variants, the recognition of which is important to avoid diagnostic misinterpretation, to predict outcome, and to guide the selection of the most appropriate therapeutic approach. This article reviews characteristic pathologic features and key clinical aspects of UC and its most common variants.

Histologic Variants of Infiltrating Urothelial Carcinoma

Context.—The spectrum of urothelial carcinoma is broad, and variant morphologies are being reported continually. Many of these variants have been extensively documented and even established as subclasses of urothelial carcinoma.

Objective.—To review the established and more recently described variants of urothelial carcinoma. The significance of recognizing these variants is discussed.

Data Sources.—The literature is reviewed in conjunction with our experience pertaining to urothelial carcinomas of the bladder and ureters.

Conclusions.—Urothelial carcinoma displays many forms, and some of these variant morphologies may introduce diagnostic difficulties because of their similarity to other malignancies and/or benign lesions. Additionally, it is important to recognize variants that are associated with different outcomes from conventional urothelial carcinoma. For these reasons, familiarity with the diverse morphology of urothelial carcinoma is not simply an academic exercise but is important in providing quality care for patients affected by this disease.

Invasive micropapillary carcinoma of the urinary bladder: An immunohistochemical study of neoplastic and stromal cells

A 66-year-old man complained of hematuria. A cystoscopy revealed a non-papillary tumor and radical cystectomy was performed. Macroscopically, an ulcerative lesion was observed. Microscopically, the neoplasm showed a mixture of urothelial carcinoma, squamous cell carcinoma and micropapillary carcinoma. Immunohistochemically, micropapillary carcinoma cells were positive for cytokeratins 7 and 20, carcinoembryonic antigen and CA125. Additionally, myofibroblasts were distributed in a chicken-wire pattern in the stroma of micropapillary carcinoma. Subsequently, the patient died of carcinoma 1 year after the onset of symptoms. Our results support the previous hypothesis that bladder micropapillary carcinoma runs an aggressive clinical course and suggest that micropapillary carcinoma may show the glandular differentiation of urothelial carcinoma and show the stromal reaction by myofibroblasts resembling that of carcinoma in other anatomic sites.

Micropapillary Carcinoma of the Renal Pelvis and Ureter

PURPOSE

MPC located in the upper urinary tract is rare with only 2 cases reported to date. We report clinical and histopathological data on 26 patients to increase the knowledge of this rare entity.

MATERIALS AND METHODS

A clinical and histopathological review was performed in 943 patients with a neoplasm in the renal pelvis or ureter, diagnosed between 1971 and 1998. We identified 26 patients with MPC. No patients were alive at the end of the study.

RESULTS

Of the patients 11 had greater than 50% MPC and 15 had focal MPC (at least 10%). The incidence was 2.8%. Median patient age at diagnosis was 69 years (range 54 to 88) and the male-to-female ratio was 17:9. All except 4 patients had stage T3 disease or higher. Carcinoma in situ was identified in 64% of cases and vascular invasion was present in 81%. A total of 20 patients (77%) died of disease and only 7 survived longer than 5 years.

CONCLUSIONS

The prognosis is poor since most patients with MPC of the renal pelvis and ureter initially present with advanced disease. Stage for stage the prognosis is not different from that in nonMPC urothelial cell carcinoma. Surgery is curative in less advanced cases. However, radiotherapy and systemic chemotherapy appear to be ineffective.

Usefulness of histologic homogeneity estimation of muscle-invasive urinary bladder cancer in an individual prognosis: a mapping study

OBJECTIVES

To examine the histologic homogeneity of muscle-invasive urothelial cell carcinoma of the bladder, with conventional and nonconventional (eg, squamous, glandular, or variants) differentiation, to assess its influence on prognosis.

METHODS

With organ mapping, we investigated 38 cystectomy specimens. Each entire bladder was cut into 88 slices according to an identical topographic scheme. From all the bladder slices, 1231 slices that included tumor were chosen for the histologic study. We examined the diagnostic significance, extension, and number of histologic differentiation types.

RESULTS

The extension of nonconventional differentiation, with any proportion of histologic type, had an unfavorable impact on survival time. The number of nonconventional differentiation types increases in the presence of a sarcomatoid, an undifferentiated, a nested, or a micropapillary pattern. The increased number of differentiation types had an unfavorable influence on survival time. Patients with a more than 80% classic urothelial cell carcinoma pattern had a favorable prognosis, which increased further with increasing percentages of this differentiation type.

CONCLUSIONS

Muscle-invasive urinary bladder cancers are not a homogenous group of tumors. Our results suggest that a precise assessment of the extension and number of histological differentiation types may be an individual prognostic factor. Conventional differentiation with at least 80% extension seems to be prognostically favorable. Nonconventional differentiation, especially with greater extension and a greater number of types, could imply a worse prognosis.

Primary invasive micropapillary carcinoma of the colon

AIMS

Invasive micropapillary carcinoma (IMPC) is associated with frequent lymph node metastasis and adverse clinical outcome. IMPC has been reported in breast, urinary bladder, ureter, lung and parotid gland but not in colon. We present the clinicopathological features of three cases of primary IMPC of the colon with a review of the literature.

METHODS AND RESULTS

The patients (one man and two women) were 53, 67 and 68 years old, respectively. The size of the tumour ranged from 20 to 100 mm in diameter. Histologically, all cases were composed predominantly of papillary tumour cell clusters with spaces in a background of fine fibrocollagenous stroma. One of the tumours (case 1) was nearly completely composed of IMPC, but the other two were associated with foci of adenocarcinoma and concurrent mucinous carcinoma, respectively. MUC1 was positive in all cases, suggestive of reverse cell orientation which is responsible for its unique histological features.

CONCLUSIONS

We report three cases of primary IMPC of the colon. Its clinical significance remains undetermined but the presence of this component may represent a poor prognostic factor.

Carcinoma micropapilar de vejiga: aportación de un caso y revisión de la bibliografía

Micropapillary carcinoma is an uncommon pathologic variant of bladder carcinoma with aggressive behavior. Its usual presentation is like a high grade and high stage carcinoma and associated with other histologic types in different proportion. It doesn't differ clinically from normal transitional cell carcinoma of the bladder. Studies of molecular markers are still contradictories. Treatment should be early and aggresive, based on surgical therapy as radiotherapy and chemotherapy have shown limited results. We report a 72 year old man suffering from low urinary tract symptoms for years and recently presented gross hematuria. He was diagnosed as high stage micropapillary carcinoma. One year after radical cystectomy and subsequent chemotherapy based on carboplatin and gemcitabine, progression of the disease was shown on CT and the patient died 14 months after the diagnosis.