Epithelioid Angiosarcoma of the Bladder: A Series of 9 Cases

Common Diagnostic Challenges in Genitourinary Mesenchymal Tumors: A Practical Approach

Mesenchymal neoplasms within the genitourinary tract include a wide spectrum of tumors, ranging from benign to malignant, and tumors of uncertain malignant potential. Except for stromal tumors of the prostate, which originate from the specific prostatic stroma, these neoplasms generally resemble their counterparts in other body sites. The rarity of these neoplasms and the limitation associated with small biopsy samples present unique diagnostic challenges for pathologists. Accurate diagnosis is paramount, as it significantly influences prognosis and guides management and treatment strategies. This review addresses common diagnostic scenarios, discusses key differential diagnoses, and sheds light on potential diagnostic pitfalls.

Pan-keratin Immunostaining in Human Tumors: A Tissue Microarray Study of 15,940 Tumors

To evaluate the efficiency of pan-keratin immunostaining, tissue microarrays of 13,501 tumor samples from 121 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types were analyzed by immunohistochemistry. In normal tissues, strong pan-keratin immunostaining was seen in epithelial cells. Staining intensity was lower in hepatocytes, islets of Langerhans, and pneumocytes but markedly reduced in the adrenal cortex. Pan-keratin was positive in ≥98% of samples in 62 (83%) of 75 epithelial tumor entities, including almost all adenocarcinomas, squamous cell and urothelial carcinomas. Only 17 of 121 tumor entities (13%) had a pan-keratin positivity rate between 25% and 98%, including tumors with mixed differentiation, endocrine/neuroendocrine tumors, renal cell carcinomas, adrenocortical tumors, and particularly poorly differentiated carcinoma subtypes. The 15 entities with pan-keratin positivity in 0.9%-25% were mostly of mesenchymal origin. Reduced/absent pan-keratin immunostaining was associated with high UICC stage (p = 0.0001), high Thoenes grade (p = 0.0183), high Fuhrman grade (p = 0.0049), advanced tumor stage (p < 0.0001) and lymph node metastasis (p = 0.0114) in clear cell renal cell carcinoma, advanced pT stage (p = 0.0007) in papillary renal cell carcinoma, and with advanced stage (p = 0.0023), high grade (p = 0.0005) as well as loss of ER and PR expression (each p < 0.0001) in invasive breast carcinoma of no special type (NST). In summary, pan-keratin can consistently be detected in the vast majority of epithelial tumors, although pan-keratin can be negative a fraction of renal cell, adrenocortical and neuroendocrine neoplasms. The data also link reduced pan-keratin immunostaining to unfavorable tumor phenotype in in epithelial neoplasms.

Non-urothelial and urothelial variants of bladder cancer

Non-urothelial bladder cancers make up a rare minority of all genitourinary (GU) tract histologic cancers since urothelial cancer (UC) makes up the most common histologic subtype. Bladder cancer variant histology (BCVH) or urothelial variants also occur rarely though distinction is important given aggressive presentation and natural history. While methods for diagnosis and treatment of typical urothelial cancers (UC) are well-established, there are no clear guidelines with regard to the diagnosis of non-urothelial bladder cancers, which often results in misdiagnosis and treatment delay. This review will focus on the clinicopathologic characteristics of the most common non-urothelial bladder cancers, to be distinguished from bladder cancer variant histology containing a UC component. The role of genomics in non-urothelial bladder cancers is evolving and the use of biomarkers to guide the diagnosis and treatment of these tumors remains a key area of unmet need. Treatment of these cancers will be discussed in a companion review.

MYC Amplification in Epithelioid Angiosarcoma of the Urinary Bladder and Prostate Following Prostate Radiotherapy: A Case Report with a Novel Molecular Alteration

Epithelioid angiosarcoma is a rare variant of angiosarcoma. Radiation-associated epithelioid angiosarcoma of the urinary bladder and prostate is an exceedingly rare tumor and there are only 8 cases of epithelioid angiosarcoma of the urinary bladder and prostate associated with previous radiotherapy in the literature. To the best of our knowledge, MYC gene amplification has not been previously reported in epithelioid angiosarcoma of the urinary bladder and prostate following radiotherapy, although it is observed in radiation-associated angiosarcoma of other anatomic sites. Here we report the first case of epithelioid angiosarcoma of the urinary bladder and prostate with MYC gene amplification detected by fluorescence in situ hybridization (FISH) analysis in a 70-year-old male patient 10 years after receiving radiation and hormonal therapy for prostate cancer.

Primary bladder angiosarcoma synchronous with prostatic acinar adenocarcinoma in an 82-year-old male

Primary bladder angiosarcoma is a rarely encountered and poorly described malignancy. Only 34 cases have been described in the English literature according to PubMed, accounting for only 2% of the genitourinary soft tissue sarcomas and 0.6% of all bladder tumors. We report a case of a primary angiosarcoma of the urinary bladder in an 82-year-old patient and present the clinical history, histopathological and immunohistochemical features of this tumor, in order to provide better understanding of the diagnosis, possible therapies and clinical outcome.

Clinicopathologic and immunohistochemical study of breast angiosarcoma

Breast angiosarcoma (AS) is a rare malignancy which can be classified into primary or secondary as a result of breast cancer therapy. On histology, breast AS has a wide spectrum of morphologic presentations, and its diagnosis can be challenging based on morphologic evaluation alone. Here, we studied 10 cases of breast AS diagnosed at our institution during a 20-year period, in which 7 cases were radiation-associated AS (RA-AS) and 3 cases were primary AS (P-AS). The average latency between radiotherapy and RA-AS was 8.1 years. RA-AS mostly occurred in breast skin, while all P-AS involved breast parenchyma. All 10 AS cases were high grade, including 4 RA-AS cases demonstrating epithelioid morphology. Histologic morphologies of AS varied from confluent growth of atypical spindle or epithelioid cells to scattered marked pleomorphic cells. Some cases appeared deceptively bland or low grade, but the presence of areas of haemorrhage ('blood lake') or necrosis upgraded them to high grade lesions. Additionally, some epithelioid RA-AS cases with lymphatic differentiation (D2-40 positive) showed pseudopapillary morphology characterized by discohesive cells sloughing off at periphery of vascular cores, resembling papillary breast carcinoma. P-AS did not show prominent vesicular nuclei and/or conspicuous nucleoli, which were features observed in RA-AS. C-MYC immunostain results showed P-AS was completely negative or focal weakly positive in hypercellular areas. In comparison, RA-AS were consistently positive for c-MYC. Epithelioid RA-AS with lymphatic differentiation tended to show stronger and/or more diffuse c-MYC positivity than other AS cases. CD31 and ERG immunostains showed positivity in all cases, while CD34 were negative in some cases with lymphatic differentiation. This study offers a detailed morphologic and immunohistochemical assessment of a rare tumor of the breast that is important to recognize. Common differential diagnosis for breast AS, including post-radiation atypical vascular proliferation (AVP), are also reviewed and discussed.

Angiosarcoma of the Urinary Bladder Following Radiotherapy: Report of a Case and Review of the Literature

Background and objectives: Angiosarcomas are uncommon and extremely aggressive malignancies derived from vascular endothelial cells. Although they can occur anywhere in the body and at any age, they are more frequently found in the skin of the head and neck regions and in the elderly. Few cases have been recorded in deep soft tissues and in parenchymal organs. Angiosarcomas of the urinary bladder are exceedingly rare. They usually arise in adult patients with a history of radiation therapy, cigarette smoking, or exposure to chemical agents (e.g., vinyl chloride). Despite multidisciplinary treatment approaches combining surgery, radiotherapy, and chemotherapy, prognosis is dismal. Materials and Methods: We describe a case of a 78-year-old Caucasian man presenting with a vesical mass incidentally discovered with abdominal computerized tomography (CT). He underwent transurethral resection of the bladder (TURB), and histology was compatible with angiosarcoma. Results: The patient had been a heavy smoker and his medical history included therapeutic irradiation for prostate cancer eight years previously. Radical cystoprostatectomy was feasible, and pathologic examination of the surgical specimen confirmed angiosarcoma involving the urinary bladder, prostate, and seminal vesicles. Post-operative peritonitis resulted in progressive multi-organ failure and death. Conclusions: Angiosarcoma primary to the urinary bladder is seldom encountered, however, it should be considered in the differential diagnosis of vesical tumors, especially in elderly men with a history of pelvic radiotherapy.

Angiosarcomas: histology, immunohistochemistry and molecular insights with implications for differential diagnosis

Angiosarcomas (AS) represent a heterogenous group of tumors with variable clinical presentation. AS share an important morphologic and immunohistochemical overlap with other sarcomas, hence the differential diagnosis is challenging, especially in poorly-differentiated tumors. Although molecular studies provide significant clues, especially in the differential diagnosis with other vascular neoplasms, a thorough hematoxylin and eosin analysis remains an essential tool in AS diagnosis. In this review, we discuss pathological and molecular insights with emphasis on implications for differential diagnosis in cutaneous, breast, soft tissue and visceral AS.

"Man in Istanbul" Lesions of the Urinary Tract (Known Entities in an Unusual Context): Melanoma, Carcinoid Tumors, Epithelioid Angiosarcoma

Certain tumors are more difficult to recognize when they present in an unusual location. Within the urinary tract, primary melanomas, carcinoid tumors, or epithelioid angiosarcoma could present diagnostic challenges due to their infrequent occurrence. This article emphasizes the clinical and histopathologic features of these entities and their differential diagnoses including the immunophenotype and their prognoses.

Metastatic squamous cell carcinoma with pseudoangiosarcomatous features and aberrant expression of vascular markers

Squamous cell carcinoma with pseudoangiosarcomatous features is a rare but well-recognized variant of squamous cell carcinoma. These tumors exhibit complex anastomosing channels lined by neoplastic cells, histologically mimicking a vasoformative mesenchymal tumor. Immunohistochemically, the published cases expressed epithelial markers and were consistently negative for vascular markers. Squamous cell carcinoma with pseudoangiosarcomatous features and aberrant expression of vascular markers has never been reported. Herein, we report two cases of metastatic poorly-differentiated squamous cell carcinoma with pseudoangiosarcomatous morphologic features which showed immunoreactivity for vascular markers (CD31, Fli-1, and ERG). One case (left thigh skin squamous cell carcinoma with abdominal wall metastasis) showed strong and diffuse positivity for vascular markers, and the final diagnosis was confirmed with electron microscopy. The second case (squamous cell carcinoma of unknown primary site with bone metastasis) showed patchy positivity for both squamous and vascular markers. This is the first report of squamous cell carcinoma with pseudoangiosarcomatous features and aberrant expression of vascular markers, which resembles angiosarcoma both morphologically and immunohistochemically, and may represent a potential diagnostic pitfall. It is of crucial importance for pathologists to be aware of metastatic squamous cell carcinoma with such unique features, so that misdiagnosis and inappropriate treatment will be avoided.

Angiosarcoma of the Bladder: Review of the Literature and Discussion About a Clinical Case

Our reported case is a 72 year-old man who presented with hematuria. A transurethral resection of the bladder tumor (TURB-T) has been performed. Histopathological diagnosis was an epithelioid angiosarcoma. CT scan revealed a bladder thickening. The treatment consisted in a complete pelvectomy with urinary and digestive diversion. Following the operation, the patient developed liver and pulmonary metastasis. He died 5 months after the initial diagnosis.

Post-radiation epithelioid angiosarcoma of the urinary bladder and prostate

Angiosarcoma of the lower urinary tract is exceedingly rare. A minority of cases are associated with local radiotherapy. Epithelioid angiosarcoma is a variant of angiosarcoma composed of large rounded epithelioid endothelial cells that are positive for cytokeratin on immunostaining. There are only two cases of post-radiation epithelioid angiosarcoma reported in the urinary bladder, and none in the prostate gland. We report a case of epithelioid angiosarcoma involving the urinary bladder and prostate in a patient with a history of radiotherapy for prostatic adenocarcinoma. A brief review of literature regarding post-radiation epithelioid angiosarcomas in the lower urinary tract is discussed.

Angiosarcoma arising in association with vascular Dacron grafts and orthopedic joint prostheses: clinicopathologic, immunohistochemical, and molecular study

Angiosarcoma may rarely arise near an inert foreign body material including vascular grafts and metal joint prostheses. Sixteen such cases have been reported since 1972 but mostly in the radiologic or surgical literature without detailed histologic or molecular analyses. We herein describe the clinicopathologic and molecular features of 2 new cases and reanalyzed 3 previously reported cases of angiosarcoma that developed in association with Dacron grafts for vascular repair (n=3) or related to orthopedic metal prostheses for joint replacement (n=2). All patients were men aged 50 to 84 years (median, 71 years). Mean time to development of angiosarcoma was 9 years (range, 4.6-17 years). Symptoms were recurrent bleeding/loosening of prosthesis for suspected infection (in the joint prosthesis cases) and fatigue, weight loss, and abdominal symptoms in the Dacron-associated cases. Four patients died of disease within 1 to 24 months (mean, 8 months). One patient was alive after radical surgery, radiochemotherapy, and embolization of pulmonary metastases (17 months). Histologically, all tumors were high-grade epithelioid neoplasms with a predominant solid growth pattern and variable vasoformation. All tumors expressed CD31, ERG, FLI-1, and variably pancytokeratin (diffuse in 3 cases), but none expressed D2-40, MDM2, or CDK4. Fluorescence in situ hybridization analysis revealed no MDM2 or CDK4 alterations. MYC was expressed in all cases, but only 1 case was MYC amplified by fluorescence in situ hybridization. Angiosarcomas are exceedingly rare fatal complications of long-standing metal and Dacron prostheses. Awareness of their morphology and frequent cytokeratin expression is necessary to avoid misdiagnosis as metastatic carcinoma. Limited awareness of their existence explains delayed clinical diagnosis in most of cases. Absence of MDM2/CDK4 alterations underlines their distinction from intimal-type sarcomas.

[Mesenchymal tumors of the urinary bladder]

Mesenchymal tumors and tumor-like lesions of the urinary bladder are rare. They encompass a heterogeneous group of reactive pseudosarcomatous tumor-like changes and benign neoplastic lesions as well as malignant neoplasms (sarcomas) with variable biological behavior. The well-known differential diagnostic difficulties related to these conditions are mainly due to their rarity and thus limited experience and familiarity with their histological features and due to the significant morphological overlap between fully benign reactive conditions and aggressive malignant neoplasms. The distinction between them may on occasion represent a real challenge and is associated with several pitfalls. This overview summarizes the clinicopathological and differential diagnostic aspects of the most important lesions and discuss their differential diagnosis in the light of current knowledge.