Atypical Intraductal Proliferation in Prostate Needle Core Biopsy: Validation as a Marker of Unsampled Adverse Pathology in a Clinicopathologic Series of 142 New Patients.

Atypical intraductal proliferation (AIP) of the prostate is characterized by morphologic features exceeding that of high-grade prostatic intraepithelial neoplasia but not meeting strict diagnostic criteria for intraductal carcinoma. We examined the clinical significance of AIP in biopsy specimens. Patients with AIP diagnosed on biopsy were identified from surgical pathology archives.

Impact of Neoadjuvant Chemotherapy on Pathologic Downstaging in Patients With Variant Histology Undergoing Radical Cystectomy.

Introduction: Variant histology (VH) bladder cancer is often associated with poor outcomes and the role of neoadjuvant chemotherapy (NAC) remains incompletely defined. Our objective was to determine comparative pathologic downstaging at radical cystectomy (RC) following NAC for patients with and without VH.

Patients And Methods: Patients who underwent RC at 2 tertiary referral centers (1996-2018) were included.

Myxoid Pseudotumor Involving the Renal Sinus: Clinicopathologic Study of 33 Cases Supporting a Distinct Benign Non-neoplastic Lesion.

We describe 33 cases of myxoid pseudotumor involving the renal sinus from 31 patients. Patients included 21 men and 10 women, ages 30 to 95 years. Twenty-seven cases (82%) had an associated malignancy, including urothelial carcinoma of the renal pelvis (22 cases), clear cell renal cell carcinoma (3 cases), urothelial carcinoma of the bladder (1 case), and poorly differentiated carcinoma of uncertain lineage (1 case).

Papillary Renal Cell Carcinoma With Microcystic Architecture Is Strongly Associated With Extrarenal Invasion and Metastatic Disease.

Papillary renal cell carcinoma (PRCC) is well-recognized as a morphologically and molecularly heterogenous group of kidney tumors with variable clinical behavior. Our goal was to analyze a unique histologic pattern of PRCC we have observed in routine practice to evaluate for potential clinical significance or distinct molecular signature. We identified 42 cases of PRCC showing a morphologically distinct architecture characterized by numerous epithelial-lined cysts containing the papillary tumor (herein called "microcysts"), which are typically separated by fibrous stroma.

Testicular Germ-Cell Tumors with Spermatic Cord Involvement: A Retrospective International Multi-Institutional Experience.

The 8th Edition of the American Joint Committee on Cancer (AJCC) Staging Manual designates discontinuous involvement of spermatic cord soft tissue by testicular germ cell tumors as a metastatic deposit. We conducted a retrospective international multi-institutional study to validate the current recommendations. Thirty-three (72%) nonseminomatous and 13 (28%) seminomatous testicular germ cell tumors were collected from 15 institutions in America, Europe, and Asia.

Distal Tubular Hyperplasia: A Proposal for a Unique Form of Renal Tubular Proliferation Distinct From Papillary Adenoma.

We identified an unusual pattern of renal tubular proliferation associated with chronic renal disease, found in 23 patients, diffusely (n=12), or focally (n=11). Incidence was 5% of end-stage renal disease kidneys from one institution (8/177) and 7/23 patients with acquired cystic kidney disease-associated renal cell carcinoma from another. Most (19 patients) had 1 or more neoplasms including papillary (n=9), acquired cystic kidney disease (n=8), clear cell (n=4), or clear cell papillary (n=3) renal cell carcinoma.

Urothelial Carcinomas With Trophoblastic Differentiation, Including Choriocarcinoma: Clinicopathologic Series of 16 Cases.

Trophoblastic differentiation (including choriocarcinoma) arising in urothelial carcinoma has been described in numerous case reports, but never in a single series. We present a series of these tumors, describing the morphologic spectrum, applying traditional and novel immunohistochemical stains, and characterizing clinical follow-up. We identified 16 cases, arising predominantly in the bladder (N=14), but also the ureter (N=1) and prostatic urethra (N=1).

Malignant solitary fibrous tumour of the prostate: four cases emphasising significant histological and immunophenotypical overlap with sarcomatoid carcinoma.

Solitary fibrous tumour (SFT) is well-described in the urinary tract, but malignant examples are rare. We studied our experience with high grade malignant SFT of the prostate to address the degree of histological and immunophenotypical overlap with sarcomatoid carcinoma and prostatic stromal sarcoma. Four cases were identified from the surgical pathology consultation archives.

Non-invasive papillary urothelial carcinoma with 'micropapillary' architecture: clinicopathological study of 18 patients emphasising clinical outcomes.

Aims: Invasive micropapillary carcinoma is a recognised aggressive urothelial carcinoma variant. One prior study focusing on non-invasive (pTa) high-grade papillary urothelial carcinoma with micropapillary architecture has been reported.

Methods And Results: We collected bladder transurethral resection specimens showing non-invasive high-grade papillary urothelial carcinoma with non-hierarchical secondary papillae lacking fibrovascular cores (i.

"Renal Cell Carcinoma With Leiomyomatous Stroma" Harbor Somatic Mutations of TSC1, TSC2, MTOR, and/or ELOC (TCEB1): Clinicopathologic and Molecular Characterization of 18 Sporadic Tumors Supports a Distinct Entity.

Renal cell carcinoma with (angio) leiomyomatous stroma (RCCLMS) is included as a provisional entity in the 2016 World Health Organization (WHO) classification of renal epithelial neoplasia; however, debate remains whether it represents a distinct entity or a heterogenous group of renal cell carcinomas (RCCs) with overlapping morphology. Also, its relationship to similar tumors occurring in the setting of tuberous sclerosis complex (TSC) is not fully addressed. We analyzed the clinicopathologic, immunohistochemical, and molecular characteristics of 23 sporadic RCCs associated with smooth muscle stroma and classified them into 2 groups, independent of molecular results: (1) RCCLMS (n=18) and (2) clear cell renal cell carcinoma (CCRCC) (n=5).

Atypical intraductal proliferation detected in prostate needle biopsy is a marker of unsampled intraductal carcinoma and other adverse pathological features: a prospective clinicopathological study of 62 cases with emphasis on pathological outcomes.

Aims: Intraductal proliferations of the prostate with more complexity and/or cytological atypia than high-grade prostate intra-epithelial neoplasia (HGPIN), but falling short of intraductal carcinoma (IDC-P), are described as 'atypical intraductal proliferation' (AIP). When present in needle biopsy (NBX) without IDC-P, the clinical significance is not known.

Methods And Results: Sixty-two NBX cases were diagnosed as AIP over 7 years with estimated incidence of 1%.

Immunohistochemical Pitfalls in Genitourinary Pathology: 2018 Update.

Immunohistochemistry may be a very useful adjunct to morphologic diagnosis in many areas of surgical pathology, including genitourinary pathology. In this review, we address common diagnostic dilemmas where immunophenotypic analysis may be utilized and we highlight pitfalls specific to each scenario. For prostate, we review the diagnosis of limited prostatic adenocarcinoma and the distinction of high-grade prostatic adenocarcinoma from urothelial carcinoma.

Acquired Cystic Disease-associated Renal Cell Carcinoma (ACD-RCC): A Multiinstitutional Study of 40 Cases With Clinical Follow-up.

The incidence of renal cell carcinoma (RCC) is known to be higher in patients with end-stage renal disease, including those with acquired cystic kidney disease due to dialysis. Acquired cystic disease (ACD)-associated RCC was recently incorporated into the 2016 WHO Classification of Tumors of the Urinary System and Male Genital Tract as a distinct entity and is reportedly the most common RCC arising in end-stage renal disease. In this study, we sought to further describe clinicopathologic findings in a large series of ACD-RCC, emphasizing histologic features, immunophenotype, clinical outcome, and patterns of disease spread.

Metastatic melanoma with dedifferentiation and extensive rhabdomyosarcomatous heterologous component.

Melanoma may undergo dedifferentiation and sarcomatous transformation with loss of melanocytic markers. Dedifferentiated melanoma rarely forms true rhabdomyoblasts with skeletal muscle immunophenotype (rhabdomyosarcomatous heterologous component). A 52-year-old woman was diagnosed with invasive melanoma (Breslow thickness 0.

Wilms Tumor: An Uncommon Entity in the Adult Patient.

Wilms tumor, the most common kidney tumor in children, is rarely seen in adults, making it a challenge for the adult oncologist to diagnose and treat. Unlike with renal cell carcinoma, patients with Wilms tumor should receive adjuvant chemotherapy with or without radiation therapy. Adult oncologists may not be familiar with pediatric oncology protocols, so it is important to consult with pediatric oncologists who have more experience in this disease.

Composite Paraganglioma and Neuroblastoma of the Urinary Bladder: A Rare Histopathological Entity.

Paraganglioma of the urinary bladder is an uncommon clinical entity. Neuroblastoma of the urinary bladder is another rare tumor with only 7 reported cases, all in children. This report presents the case of a composite paraganglioma and neuroblastoma in a 45 year-old male who presented with dysuria and flank pain.

Enucleation/partial nephrectomy for large mixed epithelial stromal tumor and herniating into the pelvicalyceal system.

Objectives: Mixed Epithelial and Stromal Tumor of the kidney is an adult renal neoplasm. It is mostly benign in nature. Typically it is composed of a mixture of epithelial and mesenchymal components.

Pseudoangiosarcomatous urothelial carcinoma of the urinary bladder.

The pseudoangiosarcomatous pattern has been described mostly in cutaneous and some visceral squamous cell carcinomas and is unique for its striking morphologic resemblance to angiosarcoma. Herein, we describe the clinicopathologic features of 7 pseudoangiosarcomatous urothelial carcinomas that occurred in the urinary bladder. The patients included 6 men and 1 woman ranging in age from 47 to 87 years (median 70 y).

Papillary cystadenoma of the epididymis and broad ligament: morphologic and immunohistochemical overlap with clear cell papillary renal cell carcinoma.

Papillary cystadenoma is an uncommon epithelial tumor, originating within the head of the epididymis and broad ligament. When the lesion is bilateral, it is associated with von Hippel-Lindau disease. Its resemblance to metastatic clear cell renal cell carcinoma (RCC) has been noted in the literature.

Large nested variant of urothelial carcinoma: 23 cases mimicking von Brunn nests and inverted growth pattern of noninvasive papillary urothelial carcinoma.

We describe a rare pattern of urothelial carcinoma (UC) invasion consisting of large, irregular to regular nests, with bland cytology. We prospectively retrieved 23 cases of large nested UC from one of the author's consult files (2001 to 2010). The mean patient age was 63.

The utility of PAX-2 and renal cell carcinoma marker immunohistochemistry in distinguishing papillary renal cell carcinoma from nonrenal cell neoplasms with papillary features.

PAX-2, a homeogene expressed during kidney development, has been studied as a marker of renal origin in both primary and metastatic clear cell renal cell carcinoma (RCC), but not in papillary neoplasms or in comparison with RCC marker (RCCma). We studied immunohistochemical expression of PAX-2 and RCCma in 24 papillary RCC (PRCC) and 66 nonrenal cell papillary neoplasms (NRCPN) from a variety of organs. Of the PRCC, 16/24 (67%) were positive for PAX-2; 23/24 (96%) were positive for RCCma.

Invasive urothelial carcinoma with chordoid features: a report of 12 distinct cases characterized by prominent myxoid stroma and cordlike epithelial architecture.

Urothelial carcinoma is morphologically heterogeneous and many variant forms have been described. We have encountered several invasive urothelial carcinomas with a unique chordoid morphology characterized by prominent cellular cording and associated myxoid stromal matrix, a pattern closely resembling extraskeletal myxoid chondrosarcoma. This morphologic appearance, to our knowledge, has not been formally described in urothelial carcinoma.