Jae Y. Ro

Renal oncocytosis: a morphologic study of fourteen cases.

Diffuse renal involvement by numerous oncocytic nodules has rarely been described. We report 14 cases (19 specimens) with innumerable oncocytic nodules in the kidney. Invariably, these kidneys showed additional associated findings. We suggest the term renal oncocytosis for this entire morphologic spectrum. Six (43%) cases had histologically or radiologically proven bilateral involvement. Each specimen had at least one dominant tumor (2.0-10.5 cm) in addition to numerous other microscopic to macroscopic oncocytic nodules. Additional features observed were: interstitial pattern, with the oncocytic tubules and acini diffusely intermingling with and infiltrating between non-neoplastic parenchyma (one case); diffuse oncocytic change in the nonneoplastic tubules, cytologically difficult to separate from the oncocytic nodules (seven cases); and benign oncocytic cortical cysts (four cases). The dominant mass in 13 specimens was a renal oncocytoma and in two, a chromophobe renal cell carcinoma. In four specimens, the largest tumor was considered a hybrid tumor because of the presence of mixed histologic features of both tumor types. Most smaller nodules had the morphologic features of renal oncocytoma, but a few had the appearance of chromophobe renal cell carcinoma or nodules with hybrid features. We conclude that the presence of numerous oncocytic nodules may be associated with a wide spectrum of oncocytic changes in the kidney. The association of numerous renal oncocytoma-like nodules with lesions having a mixed morphology or a morphology of pure chromophobe renal cell carcinoma suggests that they may constitute a morphologic spectrum of oncocytic tumors and that renal oncocytoma and chromophobe renal cell carcinoma may arise from a common progenitor lesion.

Extranodal follicular dendritic cell sarcoma of the head and neck region: three new cases, with a review of the literature.

Extranodal follicular dendritic cell (FDC) sarcoma of the head and neck region is uncommon, with 16 well-documented cases previously reported (four in the tonsil, four in the pharynx, two in the palate, five in the soft tissue, and one in the thyroid). We here report an additional three cases of extranodal FDC sarcoma in the tonsil (two cases) and pharynx (one case). In these new cases, the neoplastic cells were arranged in diffuse, fascicular, and vaguely whorled growth patterns. A background lymphocytic infiltrate was sprinkled throughout the neoplasms, with focal prominent perivascular cuffing. Scattered multinucleated giant cells were present. Immunohistochemically, tumor cells were strongly and diffusely positive for follicular dendritic cell markers CD21 and CD35. Tumor cells were diffusely positive for fascin and negative for leukocyte common antigen, S-100 protein, cytokeratin, and Epstein-Barr virus (EBV) latent membrane protein-1 (EBV-LMP). EBV was also not detected in the tumor cells by in situ hybridization for EBV-encoded RNAs. FDC sarcomas are probably an underrecognized neoplasm, especially when they occur in extranodal sites in the head and neck region. Two of the three new cases we report were initially misdiagnosed, and five cases of extranodal FDC sarcoma in the head and neck region reported in the recent literature were initially misdiagnosed. Our aim is to complement the current understanding of this neoplasm and alert pathologists to this rare entity in this region to avoid misdiagnosis. Recognition of extranodal FDC sarcoma requires a high index of suspicion, but this tumor has numerous distinctive histological features that should bring the neoplasm into the differential diagnosis. Confirmatory immunohistochemical staining with follicular dendritic cell markers such as CD21 and/or CD35 is essential for the diagnosis. Correct characterization of this neoplasm is imperative given its potential for recurrence and metastasis.

Immunohistochemical analysis of clear cell carcinoma of the gynecologic tract

Clear cell carcinoma of the gynecologic tract has been defined in terms of its clinical and histologic features; however, its immunophenotypic profile has not been fully characterized. Seventeen cases of primary clear cell carcinoma from various sites within the female genital tract (11 ovary, 5 uterus, 1 vagina) were analyzed by immunohistochemistry. These tumors were assessed for the expression of cytokeratin 7 (CK7), cytokeratin 20 (CK20), low and high molecular weight cytokeratins (CAM5.2 and 34&bgr;E12, respectively), carcinoembryonic antigen (CEA), Leu-M1, vimentin, estrogen receptor (ER), progesterone receptor (PR), bcl-2, p53, HER-2/neu, and CA-125. The characteristic immunoprofile for all sites was positivity for CK7, CAM5.2, 34&bgr;E12, CEA, Leu-M1, vimentin, bcl-2, p53, and CA-125; variably positivity for ER and HER-2/neu; and negativity for CK20 and PR. For comparison, two cases of urologic clear cell carcinoma (1 bladder, 1 urethra) were also studied, and their profile was found to be similar to the gynecologic cases. Aside from minor differences, clear cell carcinoma appears to have the same immunophenotype regardless of whether it originates in the endometrium, ovary, or genitourinary tract. Much of its profile is similar to other gynecologic adenocarcinomas, but some of the markers studied may be useful in the differential diagnosis of this tumor.

Lymphovascular Invasion in Transurethral Resection Specimens as Predictor of Progression and Metastasis in Patients With Newly Diagnosed T1 Bladder Urothelial Cancer

PURPOSE We evaluated the clinical significance of lymphovascular invasion in transurethral resection of bladder tumor specimens in patients with newly diagnosed T1 urothelial carcinoma of the bladder. MATERIALS AND METHODS Enrolled in the study were 118 patients with newly diagnosed T1 urothelial carcinoma of the bladder who underwent transurethral resection of bladder tumor between 2001 and 2007. Patient records were retrieved from a prospectively maintained bladder cancer database. We evaluated the correlation between lymphovascular invasion and other clinicopathological features, and the impact of lymphovascular invasion on disease recurrence, disease progression and metastasis. RESULTS Lymphovascular invasion was histologically confirmed in 33 patients (28.0%). While lymphovascular invasion correlated with tumor grade (p = 0.002), it was not associated with gender, age, bladder tumor history, tumor size, multiplicity or concomitant carcinoma in situ. Recurrence, progression and metastasis developed in 45 (38.1%), 19 (16.1%) and 10 patients (8.5%), respectively. Univariate analysis showed that lymphovascular invasion was marginally associated with recurrence and significantly associated with progression (p = 0.011) and metastasis (p = 0.019). Multivariate Cox proportional hazards analysis revealed that recurrence was significantly associated with lymphovascular invasion (p = 0.029), and with bladder tumor history (p <0.001), tumor size (p = 0.031) and multiplicity (p = 0.043). Lymphovascular invasion was the only independent prognostic factor associated with progression (p = 0.016). CONCLUSIONS In patients with newly diagnosed T1 urothelial carcinoma of the bladder lymphovascular invasion in transurethral resection of bladder tumor specimens predicts disease progression and metastasis.

Clinicopathologic study of 24 patients with primary cardiac sarcomas: a 10-year single institution experience.

Primary cardiac sarcomas are exceptionally rare. We present a 10-year, single-institution experience with 24 primary adult cardiac sarcomas. These cases were retrieved from the Department of Pathology data file of the Methodist Hospital at Houston, TX. Clinical presentation and pathologic features were analyzed. Histologic classification was followed according to the criteria set by the World Health Organization, and grading according to the system proposed by the Federation Nationale des Centres de Lutte Contrele Cancer. There were 14 men and 10 women (male/female, 1.4:1) with a mean age of 42.2 years (range 20-68 years). The tumors involved the right atrium in 14 cases, left atrium in 6 cases, right ventricle in 2 cases, and left ventricle in 2 cases. The tumor size ranged from 2.0 to 17.0 cm (mean 7.2 cm), and, histologically, there were 10 angiosarcomas, 9 unclassified sarcomas, 3 synovial sarcomas, and 2 leiomyosarcomas. All 10 angiosarcomas originated from the right atrium, whereas 5 of the unclassified sarcomas were from the left atrium. Although cases were limited, no predilection site was found for the other histologic types. All tumors were graded as 2 (5 cases) or 3 (19 cases) in differentiation. The prognosis was poor with a median survival time of 25 months after diagnosis. The grade was not statistically significant on survival (P = .14). In conclusion, angiosarcoma and unclassified sarcomas are the most common sarcomas of the heart accounting for 76%, but rare tumors such as synovial sarcoma and leiomyosarcoma may also occur in this organ. The survival of cardiac sarcomas is poor.

Colorectal adenocarcinoma with micropapillary pattern and its association with lymph node metastasis.

Micropapillary carcinoma has been reported as an aggressive variant of carcinoma in several organs, where it is associated with frequent lymphovascular invasion and poor clinical outcome. This study explored the clinicopathological features of colorectal adenocarcinoma with a micropapillary carcinoma component and compared them with those of conventional colorectal adenocarcinoma. One hundred seventy-eight consecutive cases of surgically resected colorectal carcinomas were studied for tumor size, type, depth of invasion, nodal and distant metastases, tumor stage, and percentage and extent of micropapillary component. Among 178 cases of colorectal carcinoma, 34 (19.1%) cases had a micropapillary component, which ranged from 5 to 60% of the entire tumor. Lymph node metastasis was identified in 25 of 34 (73.5%) carcinomas with micropapillary component, whereas they were detected in 61 of 144 (42.4%) cases without micropapillary component (P=0.001). Lymphovascular invasion was identified more frequently in carcinoma with micropapillary component (41.2%) than carcinoma without micropapillary component (20.1%; P<0.05). Distant metastases occurred in 4 of 34 cases (11.7%) with micropapillary component and in 10 of 144 cases (6.9%) without micropapillary component (P=0.311). Multivariate regression analysis demonstrated that the presence of micropapillary component, as well as tumor stage and lymphovascular invasion are independent predictors of regional nodal metastasis.

Plasmacytoid transitional cell carcinoma of urinary bladder: A clinicopathologic study of 9 cases

In this report, we summarized the clinicopathologic features of 9 cases of plasmacytoid transitional cell carcinoma (TCC) of the urinary bladder, a rare variant of TCC. All 9 patients were men with a mean of age 64.3 years (range, 46 to 81 y). All but 1 patient presented with gross hematuria; the remaining patient had urgency and microscopic hematuria. Cystoscopic findings revealed a dominant solid mass with surrounding multiple papillary lesions in 6 cases and multiple masslike lesions in 3 other cases. The initial diagnosis of plasmacytoid TCC was made on transurethral resection in 8 cases and cystoscopic biopsy in 1. One patient had TNM stage I disease, 2 had stage II disease, 3 had stage III disease, and 3 had stage IV disease. Four patients were treated by radical cystectomy with chemotherapy, 2 by radical cystectomy alone, 1 each by chemotherapy or intravesical bacillus Calmette-Guerin infusion alone, and 1 did not receive any further therapy. Microscopically, all tumors contained plasmacytoid cells, which composed 30% to 100% of the entire tumor. Eight of 9 cases were associated with high-grade TCC, and transitional cell carcinoma in situ was present in 4 cases. The plasmacytoid tumor cells were characterized by eccentrically located nuclei and abundant eosinophilic cytoplasm. Interestingly, plasmacytoid transitional cell carcinoma in situ was noted in 1 case. Immunohistochemical staining demonstrated that both plasmacytoid and conventional TCC components were positive for cytokeratins 7 and 20. The mean Ki-67 labeling index was 30% (range, 10% to 50%), and p53 expression in the majority of cases was low (5% to 10%), except for in 2 cases (70% and 80%). The mean follow-up in 8 patients was 24.5 months (range, 5 to 47 mo); the other patient was lost to follow-up. Five patients died of disease from 5 to 36 months, 2 patients were alive with disease at 30 and 47 months, and 1 patient was alive and well at 36 months with no evidence of disease. In summary, plasmacytoid TCC tends to present at an advanced stage and to have a poor prognosis. Morphologic recognition and distinction from other plasmacytoid malignant neoplasms is critical for its clinical management and immunohistochemical studies may be required for differential diagnosis.

Microscopic nodes and ducts inside lymphatics and on the surface of internal organs are rich in granulocytes and secretory granules

The blood and lymphatic systems are the two well-established circulatory systems. The existence of a third circulatory system representing acupuncture meridians was claimed in the 1960s. The very existence and function of the system, however, remained uncertain. We have found that microscopic nodes and ducts inside lymphatics, as well as on the surface of internal organs of the rat. The nodes and ducts are covered by a layer of EMP-3-positive spindle-shaped epithelium with, below, a layer of vWF-positive but CD31-negative endothelium. The nodes contain a variety of immune cells, usually enriched with mast cells, eosinophils, neutrophils and histiocytes, as well as chromaffin cells, other granule-containing cells. Secretory granules originating from the mast cells in the nodes appear to pass along ductules, two or more of which make up a duct. Our results reveal a potential circulatory system whose anatomical structure and cellular content differ from the blood and lymph systems, and which may be involved in the transport of secretory granules.

PAX-2 in the diagnosis of primary renal tumors: immunohistochemical comparison with renal cell carcinoma marker antigen and kidney-specific cadherin.

The diagnosis of renal cell carcinoma (RCC) remains problematic, especially in the context of metastasis or small needle biopsy specimens. The renal cell carcinoma marker (RCCM) and kidney-specific cadherin (KSC) are considered specific markers for RCC but are expressed preferentially in specific subtypes of RCC of lower grades. This study was aimed at evaluating the usefulness of PAX-2 in the diagnosis of renal tumors and comparing it with that of RCCM and KSC. Immunostaining for PAX-2, RCCM, and KSC was performed on consecutive tissue sections of 130 renal tumors. PAX-2 was successfully detected in routine tissue specimens. Although PAX-2 seems to be more sensitive than RCCM and KSC, there is significant staining overlap in relation to histologic subtypes, justifying the use of all 3 markers, which helps detect the vast majority of renal neoplasms. PAX-2 seems to have a significant role in renal neogenesis and may represent a novel therapeutic target.

Further characterization of the muscle layers and lamina propria of the urinary bladder by systematic histologic mapping: Implications for pathologic staging of invasive urothelial carcinoma

The muscularis mucosae (MM) and muscularis propria (MP) are important landmarks for pathologic tumor (pT) staging of urinary bladder cancer, which is the quintessential prognostic factor. In our routine practice, we have occasionally noted patterns of MM, which do not always conform to the originally described configuration of thin slender bundles arranged in a single layer of interrupted, dispersed, or continuous muscle. We evaluated the lamina propria (LP), MM, and MP characteristics in 35 urinary bladder resection specimens with systematic sampling from the dome, trigone, anterior, posterior, right, and left lateral walls. Among the subsites, the trigone had a relatively flatter surface and attenuated LP depth (0.46 to 1.58 mm), about half of the thickest region which was the dome (0.98 to 3.07 mm). The MM was typically in individual or small groups of slender and wavy fascicles or wispy fibers. MM also had focal to rarely extensive hyperplastic appearance (53%, most common in dome) with 2 recognizable patterns: (a) aggregates of hyperplastic MM with haphazard outlines (33%) distinct from that of MP, and (b) hyperplastic compact MM with parallel muscle fibers and regular outline arranged singly or in small groups (45%) that occasionally strongly resembled MP muscle but distinguishable from it on the basis of the location in the LP. By distribution, these muscle bundles were more typically dispersed or formed a discernable layer (41%) as discontinuous or infrequently near-continuous layer. The LP vascular plexus was present in every section most often in association with the MM muscle; however, variations in the distribution were observed. The MP most commonly had a relatively regular interface with the LP. A distinctive pattern was noted in the trigone where occasionally there was gradual diminution of size of the MP muscle bundles as they extended to almost a suburothelial location. In 22%, isolated or small groups of compact regular hyperplastic MM muscle bundles were noted in deep LP situated between the more typical slender MM layer and the MP. In conclusion, there are additional patterns of MM other than previously described. Awareness of the occasionally hyperplastic appearance of MM muscle is important to prevent overstaging of invasive urothelial carcinoma. In transurethral resection specimens, lack of orientation may preclude distinction of the hyperplastic MM from true MP in these rare situations. The number and orientation of muscle bundles, relationship to urothelium and vascular plexus, and comparison with more characteristic MP, if present, would be helpful; isolated bundles immediately adjacent to the urothelium with loose haphazard fiber orientation and irregular outlines favor MM over MP muscle. The hyperplastic MM mimicking MP may be more challenging; isolated muscle bundles immediately adjacent to the urothelium would favor hyperplastic pattern of MM over MP muscle. Topographical variations exist among the subsites, the more superficial location of the MP and the rarity of MM in the trigone, relative abundance of hyperplastic MM in dome, and presence of the more superficial ureteral MP at its insertion in the bladder complicate the traditional pT stage evaluation of invasion in these regions. The inconsistency of a distinct MM layer and variations in the LP vascular plexus indicate that substaging of pT1 would be problematic and thus provides further support to the World Health Organization/International Society of Urological Pathology 1998 and World Health Organization 2004 recommendation against its implementation at the current time.