Imaging Patients with Kidney Failure.

The approach to imaging a patient with kidney failure continues to evolve. Overstatement of the risk of iodinated contrast material-induced (ie, contrast-induced) acute kidney injury and new guidelines for administration of gadolinium-based contrast media affect screening and the choice of contrast material. Treatment of kidney failure requires dialysis or a kidney transplant. Pretransplant imaging includes assessment for the feasibility of performing a transplant and evaluation for underlying malignancy and peripheral vascular disease. Patients with kidney failure are at high risk for renal cell carcinoma. Subtypes that occur exclusively or more commonly in patients with kidney failure, such as acquired cystic kidney disease, renal cell carcinoma, and clear cell papillary renal cell carcinoma, have specific clinical-pathologic characteristics, with indolent behavior. Performing US for dialysis planning increases the success of placement of an arteriovenous fistula, while postoperative US evaluation is essential in assessment of access dysfunction. Systemic manifestations in patients with kidney failure are multifactorial and may relate to the underlying cause of renal failure or may be secondary to treatment effects. Disturbances in mineral and bone metabolism and soft-tissue and vascular calcifications are seen in patients with chronic kidney disease and mineral bone disorder. Neurologic and cardiothoracic complications are also common. The authors provide a comprehensive overview of imaging considerations for patients with kidney failure, including the appropriate use of CT, MRI, and US with their respective contrast agents; the use of imaging in transplant workup and dialysis assessment; and the common renal and extrarenal manifestations of kidney failure. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Fat Necrosis Mimicking Renal Cell Carcinoma Recurrence Following Cryotherapy, Partial Nephrectomy, and Nephrectomy.

OBJECTIVE: To present our experience with three patients surgically treated for suspected recurrent renal cell carcinoma whose final pathology was consistent with tumefactive fat necrosis. METHODS: Three patients underwent definitive therapy for biopsy proven renal cell carcinoma (cryoablation, partial nephrectomy, and nephrectomy) and later demonstrated evidence of recurrent renal cell carcinoma on follow up imaging. All three patients underwent surgical resection of the suspected recurrences with final pathology consistent with tumefactive fat necrosis. RESULTS: The three patients were 60, 74, and 39-years old, respectively. The previous definitive therapies for renal cell carcinoma were percutaneous ablation, RAPN, and nephrectomy. Each patient had previous surgical pathology that confirmed prior renal cell carcinoma. Signs of recurrence on diagnostic imaging occurred 2 years, 23 months, and 8 months post-definitive therapy. CONCLUSION: In patients with a history of renal cell carcinoma, consideration of fat necrosis should be taken into account upon seeing imaging concerning for tumor recurrence. Continued analysis of cases with such a diagnosis will be beneficial in recognizing this possibility to avoid unnecessary surgery or therapy when possible.

Subaortic Membrane Papillary Fibroelastoma.

A 61-year-old male presented for an annual exam and received a transthoracic echocardiogram (TTE) which revealed a mobile mass arising from a subaortic membrane. Further investigations with a transesophageal echocardiogram (TEE) and cardiac computerized tomography angiography (CTA) confirmed the presence of a mobile 9 mm × 3 mm mass on a subaortic membrane. Cardiothoracic surgery was performed with an open operation removing the mass and subaortic membrane. Upon visual inspection, the mass was likened to a sea anemone and immunohistochemical staining performed pathologically confirmed the diagnosis of cardiac papillary fibroelastoma. This case represents the first reported example of a cardiac papillary fibroelastoma (PFE) arising from a subaortic membrane. Although PFEs are benign cardiac tumors, proper identification and consideration for excision of these lesions may be indicated to prevent thromboembolic complications.

Primary synovial sarcoma of the kidney-A case report and literature review.

Primary synovial sarcoma of the kidney is a very rare spindle cell neoplasm that occasionally displays epithelial differentiation. It occurs between 15-60 years of age with a mean of 35 years and a slight male predilection. Most of synovial sarcomas appear as relatively nonspecific soft tissue masses involving the kidney. This rare entity has some overlapping morphologic and immunohistochemical characteristics with other more common renal spindle cell neoplasms. Molecular tools add valuable diagnostic confirmation. We report a 56 year old male who presented to the emergency department with hematuria and abdominal pain. He had an abdominal CT-scan which showed a 6.6 cm enhancing right renal mass. Morphologic and immunohistochemical studies were directed towards synovial sarcoma with confirmation by SYT-SSX gene fusion using RT-PCR molecular technique. We reviewed the literature on the epidemiologic, histologic spectrum, immunophenotypic, clinical significance and prognosis and therapy.

Primary Hepatic Neuroendocrine Tumor with Unusual Thyroid Follicular-Like Morphologic Characteristics.

We describe a primary hepatic neuroendocrine tumor of a 57-year-old Thai woman who presented in 2004 with a suspicious mass in the left hepatic lobe. She underwent left hepatectomy for the 10.5-cm mass, called intermediate grade neuroendocrine carcinoma of unknown origin, likely metastatic. The tumor recurred in 2007, then called recurrent primary hepatic neuroendocrine tumor (PHNET), and the patient underwent liver transplant. Because of similarity between the neuroendocrine tumor and a thyroid tumor-specifically, follicular-like characteristics-immunohistochemical stains for thyroglobulin, TTF1, and calcitonin were performed. However, all were negative. All imaging studies revealed no evidence of a primary lesion other than the liver mass. In 2008, the patient's liver transplant failed because of ischemic cholangiopathy, and she underwent a second liver transplant. Seven years later, in 2015, she presented with metastatic neuroendocrine tumor of intermediate grade to the lung, consistent with metastatic PHNET. She underwent left upper-lobe wedge resection to remove the tumor. The patient is alive with no evidence of disease at 13 years after initial diagnosis. This rare variant of PHNET had thyroid-like morphologic characteristics but there is no evidence of primary thyroid tumor or thyroid markers in the primary and recurrent hepatic tumors and lung metastasis.

Invasive ductal carcinoma with in situ pattern: how to avoid this diagnostic pitfall?

Although the microscopic features of invasion are usually readily recognized, occasionally invasive ductal carcinoma may mimic the pattern of comedo ductal carcinoma in situ (DCIS) by forming large cellular nests with circumscribed borders, but lacking a definitive myoepithelial cell layer. In these cases, the histologic pattern may appear deceptively noninvasive and the absence of a myoepithelial layer can be easily overlooked. We prospectively examined 10 cases of high grade DCIS. P63, smooth muscle actin, muscle specific actin and calponin immunohistochemical stains were used to identify the presence of myoepithelial cells. In our study, 20% of apparent high grade DCIS cases did not exhibit a myoepithelial layer surrounding large, solid nests with comedo necrosis. Since invasion is defined by the absence of a myoepithelial layer, these results suggest that a DCIS-like pattern may actually represent invasive disease in some cases. Immunohistochemical studies may be essential in making this distinction and in avoiding the potential diagnostic pitfall.

Diagnostic utility of E-cadherin and P120 catenin cocktail immunostain in distinguishing DCIS from LCIS.

BACKGROUND: Breast carcinoma in situ (CIS) is classified into ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). DCIS is treated with surgical excision while LCIS can be clinically followed with or without hormonal treatment. Thus, it is critical to distinguish DCIS from LCIS. Immunohistochemical (IHC) staining for E-cadherin is routinely used to differentiate DCIS from LCIS in diagnostically challenging cases. Circumferential diffuse membranous staining of E-cadherin is the typical pattern in DCIS, whereas LCIS lacks or shows decreased E-cadherin expression. Recent studies have shown that DCIS has membranous staining of P120 catenin and LCIS has diffuse cytoplasmic staining of P120 catenin. We developed a cocktail composed of E-cadherin and P120 catenin primary antibodies so that only one slide is needed for the double immunostains. DESIGNS: Twenty-seven blocks of formalin-fixed paraffin-embedded tissue from 26 cases of DCIS or LCIS were retrieved from the archives of Houston Methodist Hospital. Four consecutive sections from the same blocks were used for H&E and immunohistochemical (IHC) stains. The E-cadherin antibody was a rabbit polyclonal antibody and the P120 catenin antibody was a mouse monoclonal antibody. The E-cadherin primary antibody was detected using a secondary antibody raised against rabbit antibody and was visualized with a brown color. The P120 catenin primary antibody was detected using a secondary antibody raised against mouse antibody and was visualized with a red color. RESULTS: Using individual antibodies, 15 of 15 DCIS lesions had diffuse circumferential membranous E-cadherin staining (brown stain) or P120 catenin staining (red stain). All 12 LCIS cases showed cytoplasmic P120 red staining or loss of E-cadherin staining when the single P120 catenin or E-cadherin antibody was used. When stained with the antibody cocktail, all 15 DCIS samples showed diffuse red and brown membranous staining without cytoplasmic stain; all 12 LCIS samples showed diffuse cytoplasmic red staining for P120 catenin but no membranous staining for E-cadherin. CONCLUSIONS: 1. This antibody cocktail can be applied in daily practice on paraffin-embedded tissue and is especially useful in small biopsies with small foci of CIS lesions. 2. Immunohistochemical staining with the antibody cocktail showed 100% concordance with the traditional single antibody immunostaining using either E-cadherin or P120 catenin antibody. 3. Our antibody cocktail includes E-cadherin as a positive membranous stain for DCIS and P120 catenin as a positive cytoplasmic stain for LCIS, which may enhance accuracy and confidence in the differential diagnoses.

Smoothelin and caldesmon are reliable markers for distinguishing muscularis propria from desmoplasia: a critical distinction for accurate staging colorectal adenocarcinoma.

An accurate distinction between deep muscularis propria invasion versus subserosal invasion by colonic adenocarcinoma is essential for the accurate staging of cancer and subsequent optimal patient management. However, problems may arise in pathologic staging when extensive desmoplasia blurs the junction between deep muscularis propria and subserosal fibroadipose tissue. To address this issue, forty-three (43) cases of colonic adenocarcinoma resections from 2007-2009 at The Methodist Hospital in Houston, TX were reviewed. These cases were selected to address possible challenges in differentiating deep muscularis propria invasion from superficial subserosal invasion based on H&E staining alone. Immunohistochemical staining using smooth muscle actin (SMA), smoothelin, and caldesmon were performed on 51 cases: 8 cases of pT1 tumors (used mainly as control); 12 pT2 tumors; and 31 pT3 tumors. All 51 (100%) had diffuse, strong (3+) immunoreactivity for caldesmon and smoothelin in the muscularis propria with a granular cytoplasmic staining pattern. However, the desmoplastic areas of these tumors, composed of spindled fibroblasts and myofibroblasts, showed negative immunostaining for caldesmon and smoothelin (0/35). SMA strongly stained the muscularis propria and weakly (1+) or moderately (2+) stained the spindled fibroblasts in the desmoplastic areas (the latter presumably because of myofibroblastic differentiation). Compared to SMA, caldesmon and smoothelin are more specific stains that allow better delineation of the muscularis propria from the desmoplastic stromal reaction which provides a critical aide for proper staging of colonic adenocarcinoma and subsequent patient care.

Folate receptor in adenocarcinoma and squamous cell carcinoma of the lung: potential target for folate-linked therapeutic agents.

CONTEXT: Lung cancer is the number one cause of cancer deaths in the United States and globally. The advent of targeted therapies has offered a new treatment paradigm for lung cancer, but currently validated and emerging drugs are effective in only a small minority of lung cancers, predominantly adenocarcinomas. Folate receptors can serve as targets for drugs attached to folate and are overexpressed in many cancers. OBJECTIVE: To determine the frequency of folate receptor overexpression in lung cancers of different cell types as potential targets for folate-linked therapy. DESIGN: High-density tissue microarrays were constructed from archival formalin-fixed, paraffin-embedded resection specimens from 188 primary stage I or stage II adenocarcinomas or squamous cell carcinomas of the lung with three 0.1-cm cores from each tumor. Tissue microarrays were immunostained for folate receptor α with mAb343 and the results scored (0 to 1+ = weak expression, 2+ to 3+ = strong expression). RESULTS: Eighty-four of 117 (72%) of the adenocarcinomas were strongly positive for the folate receptor, and 36 of 71 (51%) of the squamous cell carcinomas were strongly positive for the folate receptor. CONCLUSIONS: Our data indicate that a large percentage of lung cancers, including squamous cell carcinomas in addition to adenocarcinomas, strongly express folate receptor. This suggests that folate-linked targeted therapy can potentially be used to treat the majority of lung cancers, both adenocarcinomas and, particularly, squamous cell carcinomas, that do not respond to current targeted therapies.

Chondroblastoma-like chondroma of soft tissue: report of the first case in the base of skull.

Chondroblastoma-like chondroma (CLC) of soft tissue is a rare benign neoplasm that usually involves the soft tissues of the hand. This report describes the first case of CLC of soft tissue arising in the base of the skull. A 33-year-old man was seen with a slow growing mass in the right parotid region of his face. The noncontrast computed tomographic scans showed an 8.5-cm mass with calcifications involving the right masticator space and extending through the bone into the middle cranial fossa. The radiologic differential diagnosis included osteosarcoma, leiomyosarcoma, chondrosarcoma, and giant cell tumor. During surgery, the large lateral skull base tumor appeared to involve the middle and infratemporal fossae and eroded the surrounding bone. Although the tumor was removed piecemeal, total excision was performed. On microscopic examination, the tumor displayed lobules of mature hyaline cartilage with numerous chondroblasts, coarse calcifications including chicken wire calcifications, and scattered osteoclasts. No atypia, mitoses, necrosis, or osteoid formation was seen. The tumor was diagnosed as chondroma with chondroblastoma features of the soft tissue. His postoperative clinical course was uneventful; however, after 7 months, he had a local recurrence identified on follow-up magnetic resonance imaging. He underwent repeat surgical excision of the tumor, which showed similar histology as the previous excision. This large skull based tumor eroding the bone, which clinically and radiologically mimicked a malignant process, was an unusual presentation of a benign cartilaginous neoplasm. Pathologists should be aware that CLC may occur in the base of the skull and this lesion should be differentiated from the other benign or malignant tumors arising in this area. These lesions have a potential for local recurrence; hence, a close follow-up is recommended.

Adenocarcinoma following urinary diversion.

The use of bowel segments in urinary diversions has been associated with an increased risk of neoplasia. This report describes three cases of intestinal adenocarcinoma following urinary diversion. In the first case, a 73-year-old woman developed moderately-differentiated colonic adenocarcinoma in her Indiana pouch 10.5 years after cystectomy. The second case involved a 77-year-old man with well-differentiated adenocarcinoma in his Indiana pouch 9 years after radical cystoprostatectomy and en bloc urethrectomy. The third case involved a 38-year-old man with moderately-differentiated adenocarcinoma arising in his ileal conduit 33 years after the creation of the conduit. These cases highlight the diagnostic signs of adenocarcinoma arising in urinary diversions and emphasize the importance of lifelong surveillance in these patients.

Thyroid fine-needle aspiration: does case volume affect diagnostic yield and interpretation?

OBJECTIVE: To evaluate the effect of case volume on the diagnostic yield and interpretation of thyroid fine-needle aspiration (FNA). DESIGN: Retrospective case series. SETTING: An academic tertiary referral center and 2 community hospital centers. PATIENTS: Data were retrospectively reviewed for all consecutive patients undergoing thyroid FNA at these institutions during the 2009 calendar year. MAIN OUTCOME MEASURES: Differences in diagnostic distribution and yield among pathologists and clinicians of differing case volume. RESULTS: A total of 790 patients underwent thyroid FNA, with the results interpreted as benign (479 [60%]), atypical (166 [22%]), malignant (9 [1%]), or nondiagnostic (136 [17%]). The FNAs were performed by 134 physicians and interpreted by 16 pathologists with varying case volumes. Low-volume pathologists (<50 FNAs interpreted) were more likely to report atypical FNAs (32% vs 13%; P < .001) and less likely to call FNAs benign (50% vs 70%; P < .001) compared with high-volume pathologists (≥50 FNAs interpreted), and compared with expected normative data (benign, P < .001; atypical, P < .001). Atypical FNA findings reported by low-volume pathologist were more likely to yield benign permanent results than those read by high-volume pathologists (64% vs 42%; P < .02). Low-volume clinicians (<20 FNAs performed) were not more likely to perform nondiagnostic FNAs compared with high-volume clinicians (≥20 FNAs performed) (16% vs 15%; P = .47). CONCLUSIONS: Case volume significantly influences the pathologic interpretation of thyroid FNA, as low-volume pathologists report more atypical and fewer benign FNA results. Case volume did not have a significant impact on diagnostic yield, because thyroid FNAs performed by low-volume clinicians did not result in more frequent nondiagnostic results compared with those performed by high-volume clinicians.

Minimal or no residual prostatic adenocarcinoma on radical prostatectomy: a 5-year experience with "vanishing carcinoma phenomenon".

CONTEXT: "Vanishing carcinoma phenomenon" (VC) has been defined as the finding of minute or no cancer on radical prostatectomy specimens after a positive biopsy. OBJECTIVE: To discuss our experience with VC and to recommend guidelines for its detection. DESIGN: One thousand seven hundred forty-one radical prostatectomy specimens (2004-2009) processed by whole-mount section procedure yielded 21 (1.2%) cases with VC and 6 (0.34%) cases with minimal carcinoma (≤ 2 mm) in the radical prostatectomy specimen. To find the eluding carcinoma in VC cases or more carcinoma in minimal carcinoma cases, the following was done: 3 levels of all the paraffin blocks were obtained; if negative, the paraffin blocks were melted, the tissue was flipped, and 3 levels were prepared. The tumor bank frozen tissue was also processed for routine examination. RESULTS: Three deeper levels in the radical prostatectomy specimen of 21 VC cases failed to show malignancy; however, the flipping and recutting of the tissue yielded a focus of carcinoma (1-5 mm) in 16 of 21 cases and in 3 of 16 cases in the saved frozen tissue. In 1 of the 6 cases with minimal carcinoma, subsequent recuts of the flipped tissue displayed carcinoma (2 foci of tumor, <1 mm each). CONCLUSIONS: In VC we recommend: embed and process any remaining prostatic tissue including any saved fresh-frozen tissue; obtain 3 levels of each paraffin block; if results are negative, melt and flip the tissue and obtain 3 more levels. Following the above guidelines, a hidden carcinoma may be detected in the majority of the cases of VC.

S100P and XIAP expression in pancreatic ductal adenocarcinoma: potential novel biomarkers as a diagnostic adjunct to fine needle aspiration cytology.

OBJECTIVE: The usefulness of 2 novel biomarkers in pancreatic surgical and cytological specimens that could reliably differentiate non-neoplastic pancreatic duct and benign gut epithelium from pancreatic ductal adenocarcinoma (PDA) was evaluated. STUDY DESIGN: A total of 14 pancreatic resection specimens (RSs), 23 endoscopic ultrasound-guided fine needle aspirations (EUS-FNAs) of PDA and 8 benign pancreatic EUS-FNAs were selected. Twelve of 14 RSs had corresponding EUS-FNAs with cell blocks (CBs). Non-neoplastic pancreatic tissue, including chronic pancreatitis, was evaluated in all RSs. Immunohistochemical stains for S100P and X-linked inhibitor of apoptosis protein (XIAP) were performed on tissue and CB sections. Staining intensity (0 no staining; 1+ weak; 2+ moderate; 3+ strong) and proportion of positive cells (less than 10% negative; 1+ 10-25%; 2+ 26-75%; 3+ greater than 75%) were assessed. Positive staining was defined as ≥10% cells with at least 1+ intensity. RESULTS: The sensitivity and specificity of S100P and XIAP immunoreactivity for a diagnosis of PDA in RSs were both 100%. In contrast, the sensitivity and specificity in EUS-FNA CBs of S100P were 78.2 and 87.5% and of XIAP 82.6 and 50.0%, respectively. The combined sensitivity of S100P and XIAP was 100% in 12 RSs and 83.3% in the corresponding EUS-FNA CBs. CONCLUSION: Two novel biomarkers have very high sensitivity and specificity in the diagnosis of PDA in RSs. S100P has slightly lower sensitivity and higher specificity of PDA than XIAP in EUS-FNA specimens. We recommend using both biomarkers as cytological diagnostic adjuncts, especially in difficult cases of well-differentiated PDA versus reactive ductal epithelium.

Benign salivary gland tissue inclusion in a pulmonary hilar lymph node from a patient with invasive well-differentiated adenocarcinoma of the lung: a potential misinterpretation for the staging of carcinoma.

Benign epithelial and nonepithelial inclusions have been found in lymph nodes in multiple body sites. These inclusions have been seen in cervical, axillary, mediastinal, abdominal, and pelvic lymph nodes. They appear as benign epithelial, parathyroid, decidual, mesothelial, angiolipomatous, nevus cells, or Tamm-Horsfall protein. Although heterotopic salivary gland tissue is not infrequent in paraparotid lymph nodes, it has only been described in lymph nodes of the pulmonary hilum once. A 68-year-old woman with gastric lymphoma now in remission presented for routine follow-up and was found to have a lung mass. After a fine needle aspiration biopsy diagnosis of adenocarcinoma, lobectomy and lymph node dissection were performed. Histological sections of lung demonstrated a well-differentiated adenocarcinoma and one lymph node, which displayed a subcapsular nest of well-formed salivary glands occupying approximately one third of the nodal tissue. The inclusion was composed of acinar cells of both serous and mucinous types, but ductal type of cells were not seen. Identification of heterotopic tissue in lymph nodes is of great importance for patient management. Misdiagnosing benign glandular inclusions for metastasis could potentially lead to incorrect tumor staging. Benign salivary gland tissue inclusions should be considered in the differential diagnosis when evaluating for metastatic adenocarcinoma. The salivary gland inclusion in pulmonary hilar lymph node may be histogenetically related to the minor salivary glands, which are located within the bronchial submucosa.

Secretory phospholipase A2-IIa is involved in prostate cancer progression and may potentially serve as a biomarker for prostate cancer.

The majority of prostate cancers are indolent, whereas a significant portion of patients will require systemic treatment during the course of their disease. To date, only high Gleason scores are best associated with a poor prognosis in prostate cancer. No validated serum biomarker has been identified with prognostic power. Previous studies showed that secretory phospholipase A2-IIa (sPLA2-IIa) is overexpressed in almost all human prostate cancer specimens and its elevated levels are correlated with high tumor grade. Here, we found that sPLA2-IIa is overexpressed in androgen-independent prostate cancer LNCaP-AI cells relative to their androgen-dependent LNCaP cell counterparts. LNCaP-AI cells also secrete significantly higher levels of sPLA2-IIa. Blocking sPLA2-IIa function compromises androgen-independent cell growth. Inhibition of the ligand-induced signaling output of the HER network, by blocking PI3K-Akt signaling and the nuclear factor-kappaB (NF-κB)-mediated pathway, compromises both sPLA2-IIa protein expression and secretion, as a result of downregulation of sPLA2-IIa promoter activity. More importantly, we demonstrated elevated serum sPLA2-IIa levels in prostate cancer patients. High serum sPLA2-IIa levels are associated significantly with high Gleason score and advanced disease stage. Increased sPLA2-IIa expression was confirmed in prostate cancer cells, but not in normal epithelium and stroma by immunohistochemistry analysis. We showed that elevated signaling of the HER/HER2-PI3K-Akt-NF-κB pathway contributes to sPLA2-IIa overexpression and secretion by prostate cancer cells. Given that sPLA2-IIa overexpression is associated with prostate development and progression, serum sPLA2-IIa may serve as a prognostic biomarker for prostate cancer and a potential surrogate prostate biomarker indicative of tumor burden.

Diagnostic utility of P504S/p63 cocktail, prostate-specific antigen, and prostatic acid phosphatase in verifying prostatic carcinoma involvement in seminal vesicles: a study of 57 cases of radical prostatectomy specimens of pathologic stage pT3b.

CONTEXT: Seminal vesicle invasion by prostatic carcinoma is directly associated with tumor staging; verification is challenging when the tumor demonstrates cribriform or papillary growth patterns or there are back-to-back small-gland proliferations. P504S is overexpressed in prostatic carcinoma and high-grade prostatic intraepithelial neoplasia with cytoplasmic immunoreactivity. p63 has positive immunoreactivity in basal cell nuclei of benign prostatic glands. Many researchers use a combination of these antibodies and their different colors. OBJECTIVE: To evaluate the usefulness of a single-color P504S/p63 cocktail immunostain in verifying prostatic carcinoma within the seminal vesicle. DESIGN: Sections from 57 radical prostatectomy specimens of pathologic stage pT3b that contain seminal vesicle with prostatic carcinoma involvement were immunostained with primary antibodies against prostate-specific antigen (PSA) and prostatic acid phosphatase (PAP) and a cocktail of antibodies against P504S and p63. RESULTS: Prostatic carcinoma cells from all 57 cases were diffusely positive for P504S, PSA, and PAP with cytoplasmic staining and no p63 nuclear staining. Seminal vesicle epithelium from all 57 cases was negative for all 3 markers with distinct p63 nuclear staining of the basal cells. Benign prostatic tissue was positive for PSA and PAP, as well as for p63, but negative for P504S. CONCLUSIONS: The P504S/p63 one-color cocktail is a practical and cost-effective stain to differentiate prostatic carcinoma that involves the seminal vesicle from seminal vesicle epithelium. It is superior to PSA or PAP when sections contain both seminal vesicle and benign glands because PSA and PAP cannot distinguish benign from malignant glands.

PAX-2 expression in non-neoplastic, primary neoplastic, and metastatic neoplastic tissue: A comprehensive immunohistochemical study.

PAX-2 is a transcription factor that controls the development of the kidney, organs deriving from the mesonephric (Wolffian) duct, and those related to the Müllerian duct. Although PAX-2 is shown to be a sensitive marker for tumors derived from these organs, but whether it is specific, that is, whether other tumor types also express PAX-2, has not been systematically evaluated in either primary or metastatic tumors. Tissue sections from 937 normal or reactive tissue samples, 759 primary neoplasms, and 332 metastatic neoplasms were submitted to PAX-2 immunostain. Among the non-neoplastic tissue, PAX-2 was expressed in glomerular parietal epithelial cells, renal collecting duct cells, atrophic renal tubular cells, epithelial cells of ovarian surface, fallopian tube, endocervix, endometrium, seminal vesicle, and lymphocytes. Among the primary neoplasms, PAX-2 was noted in 104/122 (85%) of renal cell carcinoma, 31/95 carcinomas of Müllerian origin, 17/17 (100%) lymphomas, 4/4 (100%) nephrogenic adenomas, and 1/16 (6%) benign parathyroid tumors, but was negative in 477 other tumors. Among the metastatic tumors, PAX-2 was noted in 70/95 (74%) metastatic renal cell carcinomas, 14/20 (70%) metastatic tumors of Müllerian origin, 1/20 (5%) metastatic colon carcinoma of lymph nodes, 1/62 (2%) metastatic breast carcinoma of lymph nodes, but was not seen in the remaining 247 metastatic tumors. PAX-2 expression in non-neoplastic mature tissue is limited to the organs whose embryonic development depends on this transcription factor. PAX-2 is a sensitive and specific marker for tumors of renal or Müllerian origin in both primary and metastatic contexts.

Primary schwannoma in a cervical lymph node.

BACKGROUND: Spindle cell neoplasms within lymph nodes are rare and include benign and malignant tumors and primary and metastatic tumors such as palisaded myofibroblastoma, leiomyoma, leiomyosarcoma, reticular cell neoplasms, and vascular sarcomas. Ancillary studies may help distinguish these neoplasms. METHODS: A 77-year-old white woman was seen with a painless, slowly growing mass of the left neck. Her clinical history was noncontributory. An excisional biopsy was performed without complication. There has been no recurrence, to date, of the lesion. RESULTS: Gross examination, microscopic examination, immunohistochemistry, and ultrastructural studies were consistent with the diagnosis of schwannoma arising within a lymph node. CONCLUSIONS: We report the first case of intranodal schwannoma arising in a cervical lymph node. The recognition of intranodal schwannoma is important because it is cured with excision, whereas some of the other diagnostic considerations for a spindle cell lesion within a lymph node may require radiation or chemotherapy.