Focal Stain Research Articles

GATA3 Is a Useful Immunohistochemical Marker to Differentiate Variants of Renal Tubular Lesions from Different Segments of Renal Tubules

Abstract Introduction/Objective GATA3 is found in glomerular mesangial cells, and the distal tubules & collecting ducts in metanephros and eventual kidneys, but not associated with the proximal tubules and loops of Henle. We hypothesize that GATA3 can be used as a marker to identify the origin of tubular differentiation in most renal tumors. Methods/Case Report Ten negative controls and 43 renal mass lesions (RCC, papillary, clear cell papillary, and chromophobe carcinomas, oncocytoma, and polycystic kidney disease). GATA3 nuclear stain was graded as negative (absent stain), equivocal and positive (< 5 and > 5% cells, respectively). Details of their GATA3 nuclear expression was analyzed for identifying their tubular segmental origins. Results (if a Case Study enter NA) In 10 normal renal parenchyma, GATA3 was positive in mesangial cells, distal tubules, and collecting ducts, but was negative in the proximal tubules and loop of Henle. The cystic lining of glomerulocystic renal disease was stained negatively for GATA3 (proximal tubular origin), whereas pediatric and adult variants of polycystic kidney diseases was positive for GATA3 staining (distal tubular origin). 1/10 ten clear cell RCC and papillary RCC showed focal positive GATA3 stain. GATA3 showed weakly positive staining in some oncocytomas (4/11) and some chromophobe RCC (4/11), indicating that they might be derived from the junctional segment between the loop of Henle and the distal tubules. By contrast, all clear cell papillary RCC (distal tubule origin) were diffusely positive. Conclusion Our results indicate that GATA3 is a useful immunohistochemical marker to determine the developmental origin in the specific renal tubular segment for the majority of renal mass lesions. Thus, it may be useful for routine differential diagnosis of these lesions.

Low-grade oncocytic tumour expands the spectrum of renal oncocytic tumours and deserves separate classification: a review of 23 cases from a single tertiary institute

AimsLow-grade oncocytic tumour (LOT) has recently been introduced as a potential distinct entity.MethodsAt the Indiana University department of pathology, primary renal epithelial neoplasms between 2005 and 2020 were searched after...

2652 Primary Malignant Peripheral Nerve Sheath Tumor of Small Bowel and Colon Presenting With Metastases to Bone, Lung, Liver, Spleen, and Brain

INTRODUCTION: Malignant Peripheral Nerve Sheath Tumor (MPNST) is a rare diagnosis, with an incidence of 1:100,000 per year and 4–10% of soft tissue sarcoma, contains properties both neural crest cells and mesenchymal cells. Gastrointestinal MPNSTs are rare disease conditions with only 10 cases reported worldwide in the literature. CASE DESCRIPTION/METHODS: A 71-year old Portuguese male, presented with 8-week history of abdominal pain, anorexia with 20Ib weight loss. Vital signs were normal. On physical examination, a firm, tender, fixed abdominal mass in the RLQ was palpated. CT scan of the abdomen showed a 10 cm necrotic mass on the right side of the abdomen with communication to the small bowel was detected with a suggestion of a walled off perforation. Colonoscopy revealed a flattening of the terminal ileum suggesting an extrinsic compression. Biopsy of tumor consisting of mixed spindle and pleomorphic cells with focal rhabdoid features, high grade nuclear features and brisk mitotic activity. A week later, he presented with symptoms of small bowel obstruction, the CT scan at this time showed a 8 cm left sided abdominal mass with communication to the small bowel with dilation of the jejunum suggesting a new partial obstruction in addition. The patient underwent a palliative debulking of the tumor. Multiple large obstructive masses were found in the Ligament of Treitz,significant portion of the small bowel, right colon, left upper quadrant and omentum. For palliation purposes, these masses were resected and anastomosis was performed. Gross examination of the surgical specimens revealed grayish-tan cystic masses filled with brownish tan hemorrhagic material. Histology of the masses were similr to previous mass. On immunohistochemistry, showed patchy weak S100 immunoreactivity and focal BCL-2 and Neuron Specific Enolase stain immunoreactivity. Ki-67 proliferation index was 70%. The pathologic diagnosis of MPNST was established. He developed multiple bone, pulmonary, liver, splenic and hemorrhagic brain metastases. He died under hospice care within six months of his initial presentation. DISCUSSION: MPNST, occurs mostly in association with Neurofibromatosis Type 1 (8–13%). The tumor typically originates from the nerve sheaths of the major nerves in the extremities (40%), trunk/ retroperitoneal (38%) and head and neck region (21%). However, recent case reports have also documented MPNST of the liver, thyroid gland, skin, eighth cranial nerve and rarely the greater omentum without a history of radiation or NF1.

DESTRUCTIVE LESION OF THE ANTERIOR MANDIBLE: A UNIQUE PRESENTATION OF LEPROSY

Leprosy is a chronic disease caused by infection with Mycobacterium leprae. The disease has an incubation period spanning 1-20 years with an average duration of 5 years. According to the CDC, 150-200 people in the US and 250,000 people worldwide become infected with leprosy yearly. From 2006-2015, Southeast Asia reported the highest number of new cases per year. Here we report an unusual case of intraosseous leprosy of the mandible from a 31-year-old Indian-American female. The woman presented to her oral surgeon with a destructive lesion of the anterior mandible and had associated loose teeth. She reported both prior and recent trips to India. Clinical impression at the time of surgery was a central giant cell granuloma or ameloblastoma. Histopathologic examination revealed granulomatous inflammation composed of histiocytes admixed with lymphocytes, plasma cells, and neutrophils. Discrete granulomas composed of epithelioid histiocytes and multinucleated giant cells were noted. Due to the histologic findings, GMS, PAS, and AFB Ziehl-Nielsen stains were ordered and all were reported as negative. AFB Fite stains demonstrated rare positivity. The case was diagnosed as chronic granulomatous inflammatory reaction with focal Fite stain positivity, suggestive of leprosy. While the histology is suggestive of tuberculoid leprosy, correlation with systemic evaluation and lepromin skin test were recommended. The utility of the lepromin test is to better classify the type of leprosy the patient has with positive results indicating either tuberculoid or borderline leprosy and a negative reaction supporting a diagnosis of lepromatous leprosy. Few extragnathic bony cases and intraoral cases have been reported in the English literature since 1965. This case report illustrates both an unusual and interesting case of gnathic leprosy, as well as the need to recognize that with the ease of travel, lesions that are historically seen in countries other than the United states, can be seen here.

P1.02-029 Infrequent Staining Patterns in ALK Immunohistochemistry: Correlation with Fish Analysis

AKL gene rearrangements are predictive alterations in non-small cell lung carcinomas (NSCLC). Immunohistochemistry (IHC) has become a valuable tool in assessing ALK status, however unusual staining patterns, such as heterogeneous diffuse moderate and focal intense stains, may occur and can make evaluation difficult. We correlated immunohistochemistry unusual staining patterns with ALK status by fluorescence in situ hybridization (FISH). Of 851 cases tested, we found 14 (1.6%) cases with inconclusive staining patterns that can be summarized in: a) diffuse granular cytoplasmic moderate stain, with or without background mucin stain (10 cases) b) focal intense granular cytoplasmic stain in overall negative or weakly positive tumors (4 cases). IHC was performed on an automatized Benchmark staining module using Ventana ALK (D5F3) CDx assay with Optiview amplification kit. FISH was performed using ALK break-apart probe set (Vysis LSI ALK Dual Color, Abbott Molecular). Cases were considered ALK-FISH positive if ≥15% tumor cells showed split red and green signals (separation of 2 diameters or more) and/or single red signals. Of 10 moderate granular cytoplasmic stain cases, 4 had also abundant mucin background stain 6 where markedly heterogeneous with areas of weak and moderate cytoplasmic granular stain. Nine were FISH negative, one yielded no signals (uninformative result) and one specimen corresponded to an acid decalcified specimen and was not evaluated by FISH. Focal intense stain was observed in 5 samples, 3 corresponded to surgical specimens and the rest to small needle biopsies, one of the surgical specimens was FISH positive and the rest, negative. Since FDA approval of Ventana ALK (D5F3) IHC CDx Assay, IHC has become a widely used tool for assessing ALK status. Guidelines suggest that weak granular stain should be interpreted as negative and focal intense granular stain in any number of cells, as positive. Even though our sample is small, moderate granular stain was consistently negative by FISH analysis, however, focal intense stain shows more discordant results between tests. To date, no suggestions are made on what should be the minimum amount of tumor in a sample to report an IHC assay. Even though some of these patients with IHC positive/FISH negative results have been reported as responders to Crizotinib, further studies are needed. One specimen with moderate cytoplasmic IHC stain was uninformative due to lack of signals. This raises the issue of the need to standardize pre-analytical variables, which can be difficult in some areas of Latin America.

Cordycepin Prevents Bone Loss through Inhibiting Osteoclastogenesis by Scavenging ROS Generation.

Cordycepin was previously reported to have anti-tumor, anti-inflammatory and anti-oxidant activity. However, the potential role of cordycepin in bone metabolism and cell biology of osteoclasts remains unclear. In our study, we focused on the in vitro effects of cordycepin on osteoclastogenesis and its in vivo effects in ovariectomized (OVX) mice. Osteoclast differentiation, formation and fusion were evaluated by Tartrate-resistant acid phosphatase (TRAP) stain, focal adhesion stain and fusion assay, respectively. Osteoclastic bone resorption was evaluated by pit formation assay. Reactive oxygen species (ROS) generation and removal were detected by the ROS assay. OVX mice were orally administered with 10 mg/kg of cordycepin daily for four weeks. In vitro results revealed that cordycepin inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation, formation, fusion and bone resorption activity. We further proved that cordycepin treatments scavenged the generation of ROS, upregulated interferon regulatory factor 8 (IRF-8) and suppressed the activity of nuclear factor of activated T cells c1 (NFATc1) during osteoclastogenesis. In vivo results indicated cordycepin prevents bone loss, rescues bone microarchitecture, and restores bone mineralization in OVX mice. Our observations strongly suggested that cordycepin is an efficient osteoclast inhibitor and hold potential therapeutic value in preventing bone loss among postmenopausal osteoporosis patients.

Periodontal Management of Sturge-Weber Syndrome

Sturge-Weber syndrome (SWS) is a sporadic disorder and is frequent among the neurocutaneous syndromes specifically with vascular predominance. This syndrome consists of constellation of clinical features like facial nevus, seizures, hemiparesis, intracranial calcifications, and mental retardation. It is characterized by focal port-wine stain, ocular abnormalities (glaucoma), and choroidal hemangioma and leptomeningeal angioma most often involving occipital and parietal lobes. The present paper reports three cases of SWS with oral manifestations and periodontal management, which included thorough scaling and root planing followed by gingivectomy with scalpel and laser in cases 1 and 3 consecutively to treat the gingival enlargement. However, the treatment in case 2 was deferred as the patient was not a candidate for periodontal surgery.

Clinicopathologic Characteristics of 23 Cases of Invasive Low-grade Papillary Urothelial Carcinoma

To investigate the clinicopathologic and immunohistochemical features associated with invasive low-grade papillary urothelial carcinoma (LGPUC), an uncommon entity not previously described in published studies. A multicenter effort originally identified 36 cases diagnosed as invasive LGPUC by urologic pathology subspecialists; after re-review, 23 cases were included. The average patient age was 69 years (range 46-82); 20 patients were men and 3 were women. Stage pT1 disease was present in 19 (83%) of 23 and pT2 disease in 4 patients. Of the 23 cases, 13 (57%) showed a single focus of invasion and 10 multiple foci. The invasive front showed rounded, variably sized nests in 17 cases (74%) and irregular nests with retraction artifact in 6. Additional findings in the noninvasive component included inverted growth in 23, apoptotic debris in 5, focal brisk mitotic activity in 4, dispersed chromatin in individual cells in 4, and a single atypical cell in 2. Immunohistochemical stains showed focal p53 nuclear stain in 23, patchy full-thickness cytokeratin 20 stain in 20, full-thickness CD44 expression in 17, and retention of E-cadherin in 23 cases. Clinical follow-up was available for all patients. The subsequent diagnosis included papilloma in 1 patient (4%), LGPUC in 5 (22%), and high-grade papillary urothelial carcinoma in 8 (35%) of the 23 patients, with 5 demonstrating invasion. Of the latter patients, 2 developed metastatic disease. Given the risk of progressive disease in these patients, especially the limited stage pT1 disease in most patients, additional studies investigating the molecular properties and outcomes associated with this uncommon lesion are warranted.

Expression of Matrix Metalloproteinase-2 and -13 and Tissue Inhibitor of Metalloproteinase-4 in Varicose Veins

BackgroundThe relationship between the degree of expression of matrix metalloproteinases or tissue inhibitor of metalloproteinases and venous reflux remains to be investigated.Materials and MethodsPrimary varicose vein tissues were obtained from 23 patients, 18 females and 5 males, aged from 19 to 73. Cephalic or basilic veins were obtained for the control group from 10 patients who underwent vascular access for maintenance hemodialysis. Two operative techniques (high ligation with stripping or endovenous laser coagulation) were used. The expression of matrix metalloproteinase-2 and 13 and tissue inhibitor of metalloproteinase-4 in the varicose vein group and control group was assessed semi-quantitatively by immunohistochemical slides stained with primary antibodies.ResultsTwenty (87%) of the varicose vein group patients had greater or lesser saphenous vein diseases with reflux. The focal weak (+) stain for matrix metalloproteinases-2, and 13, and tissue inhibitor of matrix metalloproteinase-4 was dominant in the varicose vein group; the focal or diffuse strong stain (++ or +++) was prevalent in the control group. The differences were statistically significant (p<0.01). The degree of reflux and the duration of symptoms were not significantly related to the expression of MMP-13 (p=0.317 and p=0.654, respectively).ConclusionFurther study should be performed to investigate the relationship between the clinical characteristics related to venous hypertension or reflux and expression of MMPs and TIMP in varicose veins.

Focal Positivity for Non-Specific Esterase in AML: A Surrogate Marker to Predict AML with t(8;21)/RUNX1-RUNX1T1

Abstract 2534Introduction Cytomorphological evaluation of bone marrow remains a fast and easy accomplished tool in patients with suspected acute myeloid leukemia (AML). Some cytogenetic aberrations can be predicted by specific morphological features like abnormal eosinophils associated with inv(16)/t(16;16) and faggot cells with t(15;17). But implementations of cytogenetic and molecular tests nearly diminished the interest in studying cytomorphological features that might be associated with chromosomal aberrations. Common morphological characteristics often found in AML associated with t(8;21) are large blasts with abundant basophilic cytoplasm, containing numerous azurophilic granules, perinuclear clearing or hofs and single long and sharp Auer rods. But not all AML with t(8;21) show these characteristic signs. During our cytomorphological review for patients with AML within the German prospective multicenter randomized AML96 and AML2003 trials we observed that a focal non-specific esterase stain for blasts in t(8;21) appears to be another specific feature for this subentity. With this study we tried to analyze its predictive value for this chromosomal aberration. Materials and methodsBone marrow (BM) aspirates and peripheral blood smears of 156 eligible patients from the Study Alliance Leukemia (SAL) AML96 and AML2003 trials were investigated by conventional cytochemical methods (May-Giemsa, myeoloperoxidase, alpha-naphthyl butyrate esterase and iron staining). AML classification was performed according to FAB and WHO 2001. Diagnosis of t(8;21)/RUNX1-RUNX1T1 was made by FISH, chromosomal banding and RT-PCR analysis. Bone marrow samples from patients with AML associated with t(8;21)/RUNX1-RUNX1T1 were evaluated and reviewed by an independent and experienced morphologist. Blast morphology was evaluated for granulation, perinuclear clearing or hofs, focal positivity for non-specific esterase (NSE) and the presence of Auer rods, pseudo-Pelger neutrophils and eosinophils. Besides that we investigated its correlation for aberrant expression of CD19 and CD56 in immunophenotyping and the KIT exon-17 mutation. All statistical calculations were performed using the software program PASW statistics 17 (SPSS, Chicago, IL, USA) and R 2.10.1 (The R Foundation for Statistical Computing, 2010). ResultsOf 156 eligible patients, 72 did not have adequate bone marrow samples to assess the amount of blasts with NSE positivity; therefore, the final study cohort consisted of data sets from 84 patients. The median age was 44 years (range, 19–85 years). The distribution of gender was 39 women (46%) and 45 men (54%). The majority of cases (81%) were subclassified in FAB M2. Cytomorphology showed a focal NSE positivity in 82 patients (98% of cases). Chromosome banding analyses were performed in all cases and showed t(8;21) in all cases. Forty-three patients demonstrated additional abnormalities with 29 (35%) cases showing single additional aberrations and 14 (17%) cases having two or more additional aberrations. Focal positivity of non-specific-esterase stain was found in 25% in 11 (13%), 50% in 29 (35%), 75% in 22 (26%) and 100% in 20 (24%) of bone marrow blasts. The presence of focal NSE-positivity demonstrates a significant association with the cytogenetic aberration t(8;21) (p < 0.001). Focal NSE-positivity was present even in the absence of further morphological features associated with t(8;21). No correlation between focal NSE stain and the aberrant expression CD19 and CD56 and KIT-Mutation could be seen. In AML other than t(8;21) no focal positivity for NSE could be seen (n=100). ConclusionOur investigations could prove that focal positivity for NSE is a reliable surrogate marker to predict the chromosomal aberration t(8;21). Disclosures:No relevant conflicts of interest to declare.

Immunohistochemical analysis of kallikrein-related peptidases in the normal kidney and renal tumors: potential clinical implications

Kallikrein-related peptidases (KLKs) have been shown to be differentially expressed in various malignancies and shown to be useful tumor markers. Previous immunohistochemistry (IHC) analysis demonstrated that KLKs 5, 6, 10, and 11 have a potential prognostic significance in renal cell carcinoma (RCC). To further explore the significance of KLKs, we examined KLKs 1, 6, 7, and 15 in different subtypes of renal tumors. KLK1 has stronger expression in high grade compared to low grade clear cell RCC. However, KLK6 and KLK7 show strong expression in low grade in contrast to high grade clear cell RCC. Furthermore, the expression of KLK7 can distinguish between oncocytoma and chromophobe RCC. Oncocytoma showed diffuse, strong granular cytoplasmic staining, but chromophobe RCC showed focal weak homogeneous cytoplasmic stain. The pattern of staining of different KLKs can also be helpful in differentiating some of the subtypes of renal tumors. Our results show the potential ability of KLKs to serve as diagnostic markers and expand previous data about the prognostic significance of KLKs in kidney cancer. In addition, our study is the first to show the ability of KLK staining to distinguish various types of kidney cancers when morphology is similar.

Analysis of IMP3 Expression in Normal and Neoplastic Human Pituitary Tissues

Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is an oncofetal protein highly expressed in fetal tissue and malignant tumors but rarely found in adult benign tissues. In various tumors, IMP3 expression is correlated with increased tumor aggressiveness and reduced overall survival. To our knowledge, IMP3 expression has not been investigated in pituitary tumors. We analyzed the immunohistochemical expression of IMP3 in five normal pituitary tissues and 75 pituitary tumors (64 adenomas and 11 carcinomas) to determine if specific tumor types expressed IMP3 and if there were differences in IMP3 expression between adenomas and carcinomas. Immunohistochemical analysis showed that IMP3 was positive in four (80%) normal pituitaries with focal stain in a subset of normal anterior pituitary cells. IMP3 was expressed in 31% (20/64) of adenomas and in 36% (4/11) of carcinomas. A slightly higher level of IMP3 expression was observed in PRL-GH-TSH adenomas compared to the other types of pituitary adenomas. Expression of IMP3 was not significantly higher in carcinomas than in adenomas (p = 0.737). RT-PCR and Western Blotting supported the heterogeneous expression of IMP3. These results indicate that IMP3 is expressed both in normal and in neoplastic pituitary gland tissues without significant differences in expression levels in pituitary carcinomas.

Anaplastic lymphoma kinase–positive diffuse large B-cell lymphoma with a complex karyotype and cryptic 3′ ALK gene insertion to chromosome 4 q22-24

Anaplastic lymphoma kinase (ALK)-positive diffuse large B-cell lymphoma (DLBCL) is a rare tumor that is frequently associated with t(2;17)(p23;q23), a translocation fusing the ALK gene at 2p23 to the clathrin heavy chain gene (CLTC) at 17q23. Here, we report a unique case of ALK-positive DLBCL with plasmablastic morphology and focal cytoplasmic granular ALK stain in an HIV-negative 33-year-old man. By conventional karyotyping, the lymphoma cells were near-tetraploid and included 4 structurally normal copies each of chromosomes 2 and 17. Fluorescence in situ hybridization revealed an apparently normal, intact ALK gene on each of the 4 chromosome 2 homologs plus a cytogenetically cryptic ALK gene insertion into 2 of the 4 chromosome 4 homologs at band 4q22-24. The lymphoma cells expressed CD138, lambda light chain, focal and weak CD30, and exhibited aberrant T-cell antigens, including perforin. This case indicates that ALK-positive DLBCL is more heterogeneous at the cytogenetic/molecular level than previously recognized.

Immunomodulatory effects of ciprofloxacin in TNBS-induced colitis in mice

Crohn's exacerbation and pouchitis are commonly treated with ciprofloxacin and metronidazole. Few studies have shown an advantage of this regimen compared with other antibiotics. Most attributed the effect to its better antibacterial coverage. Others have shown an apparent anti-inflammatory effect of quinolones in several in vitro and in vivo models of inflammation other than inflammatory bowel diseases (IBD). Our objective was to test the hypothesis that ciprofloxacin may act as an anti-inflammatory agent rather than just an antibacterial drug using a model of chemical colitis. TNBS colitis was induced in BALB/c mice. The anti-inflammatory effect of ciprofloxacin compared with ceftazidime and dexamethasone was assessed. Mice treated with ciprofloxacin (7.5 mg/kg or 15 mg/kg) had significant reductions in clinical signs, body weight loss, splenic and colonic weight increase compared with saline-treated and ceftazidime-treated mice. Histologic analysis showed mild inflammation in ciprofloxacin-treated mice with a mean score of 3.8 +/- 0.5 points compared with moderate colitis scored 7.8 +/- 1.3 and 9.5 +/- 0.5 points in saline and ceftazidime-treated mice, respectively. Analysis of cytokine levels in colon homogenates showed a significant decrease of IL-1beta, IL-8, and TNFalpha levels in ciprofloxacin-treated animals. Immunohistochemistry for NFkappaB showed strong positivity in saline and ceftazidime-treated mice in contrast to weak focal stain in ciprofloxacin- and dexamethasone-treated mice. These findings imply that ciprofloxacin has an anti-inflammatory effect, rather than just an antibacterial one, making its use favorable in IBD patients.

Incidence of C4d Stain in Protocol Biopsies from Renal Allografts: Results from a Multicenter Trial

C4d staining of renal allografts is regarded as an in situ marker of active humoral rejection. Few data are available about the incidence of C4d deposition in protocol biopsies compared to indication biopsies. To evaluate whether center-specific factors influence the incidence of C4d detection, we performed a multicenter study. From three European centers, 551 protocol and 377 indication biopsies were reclassified according to the updated Banff criteria and stained for C4d. C4d results were recorded as diffuse or focal positive and statistically correlated to clinical parameters, morphology and graft survival. In the protocol biopsies, a diffuse C4d stain was found in 2.0%, and a focal stain in 2.4%. In indication biopsies, 12.2% were diffusely and 8.5% focally C4d positive (protocol:indication p < 0.0001). The incidence of C4d deposition varied significantly between centers, attributable to variable numbers of presensitized patients with more C4d positive indication and protocol biopsies. Diffuse and focal C4d stain correlated with morphology of humoral rejection in protocol as well as in indication biopsies. Protocol biopsies show a significantly lower incidence of C4d deposition than indication biopsies. Subclinical C4d detection in protocol biopsies had no significant impact on allograft survival in our series.

High-resolution ultrasonic brain imaging: Noninvasive adaptive focusing based on twin arrays

Ultrasonic imaging systems assume a constant acoustic velocity in human tissues in the beamforming process. However, in the case of brain imaging, strong skull aberrations induce a displacement of the focal stain, a spreading in the main lobe, and an increase in the sidelobes level. This limits considerably ultrasonic brain imaging applications. It has been shown that a very accurate focusing could be achieved through a human skull by using an inverse filter technique. This method, based on a set of acoustic sensors located inside the brain, demonstrated invasively that it was possible to achieve high-resolution brain imaging. A noninvasive ultrasonic method is presented. It is based on two arrays located on each side of the head. Each array focuses on the other one to deduce the aberrations induced by the skull bone. Once the effect of the skull bone in front of each array is extracted, the wavefronts are corrected and emitted. This noninvasive technique restores the position of the focal stain and lowers the secondary lobe level up to 15 dB compared to a cylindrical focusing.

A MORPHOLOGIC STUDY OF THE VASCULATURE OF MALIGNANT GLIOMAS USING THICK CELLOIDIN SECTIONS AND ALKALINE PHOSPHATASE STAIN

The combination of 100 microm thick celloidin sections and alkaline phosphatase (AP) enzyme histochemistry of the vascular endothelium offers a greatly enhanced, 3D morphologic perspective and reveals intricate details of the vasculature of brain. A study of tumor specimens obtained at craniotomy from 6 patients with glioblastomas, 1 with anaplastic oligodendroglioma and 1 with juvenile pilocytic astrocytoma was undertaken using this technique. Five of the 6 glioblastomas, the anaplastic oligodendroglioma and the low-grade astrocytoma specimen showed uniform staining of afferent tumor blood vessels. In the glioblastomas, newly formed vessels formed dense, festooned networks at the advancing edges of the tumor. Feeding arteries entered the tumor at the junction between the edge of the tumor and adjacent brain or meninges and proceeded to form striking, coiled vessels and smaller branches. The density of both small arteries and veins was greatly increased within the tumor although there was much variability. Disordered arborization, arteriole to venous and arteriole to arteriole shunts were observed, leading to a situation where arteries connected directly to veins. In necrotic areas, there were often no AP-stained vessels. In many places, arterioles and capillaries were lacking. Numerous AP-negative veins of various sizes drained the tumors. Glomeruloid proliferations were presumptively identified as focal stain smudges or clusters of capillaries arising from nearby vascular channels. Increased alkaline phosphatase staining and/or focal new vessels were seen outside necrotic areas. The pilocytic astrocytoma and the oligodendroglioma showed less dense vascularity and no formation of the focal festoons of vessels shown by the glioblastomas. This technique may be useful for the study of tumor angiogenesis and to evaluate vascularity in experimental and human brain tumors after various therapies.

Chondroitin sulfate proteoglycan specific to retinal horizontal neurons

ABSTRACT Proteoglycans (PGs) are a diverse group of highly glycosylated macromolecules that are implicated in the development and maintenance of neuronal circuitry. With its highly ordered, layered structure, the retina ideally serves to define the synthesis, processing, and distribution of these molecules within a specific cellular subpopulation. In retinal sections, monoclonal antibody (MAb) 6A2 immunostained a horizontal cell-specific antigen. Antigen 6A2 was expressed within abundant processes in the outer plexiform layer and in rare neurites that extend across the inner nuclear layer to the inner plexiform layer. Ultrastructurally, the antigen was localized to cisternae within horizontal cell somata, along tubulovesicular structures in dendrites, and in the perisynaptic space encircling presynaptic terminals of the cone photoreceptor triad. These findings suggest that this PG is synthesized within the horizontal cells, transported to the terminals, and released into the extracellular spaces just proximal to the synapse. Based on the focal stain in the adjacent photoreceptor cell, it is possible that antigen is pinocytosed by this cell and is concentrated at the ribbon synapse. In Western immunoblots of retinal homogenates, MAb 6A2 recognized a heterogeneous chondroitin sulfate (CS) PG (CSPG) of approximately 400-500 kDa. After sequential enzymatic removal of CS glycosaminoglycans, a major broad band of 300-500 kDa was identified by MAb 1B5, which detects CSPGs that bear uronic acid linked to unsulfated N-acetylgalactosamine as the initial disaccharide in the CS chain. Localization of this PG around presynaptic terminals of the horizontal neuron and at the ribbon synapse suggests that it may play a modulatory and sustaining role at the synapse.

Chondroitin sulfate proteoglycan specific to retinal horizontal neurons.

ABSTRACT Proteoglycans (PGs) are a diverse group of highly glycosylated macromolecules that are implicated in the development and maintenance of neuronal circuitry. With its highly ordered, layered structure, the retina ideally serves to define the synthesis, processing, and distribution of these molecules within a specific cellular subpopulation. In retinal sections, monoclonal antibody (MAb) 6A2 immunostained a horizontal cell-specific antigen. Antigen 6A2 was expressed within abundant processes in the outer plexiform layer and in rare neurites that extend across the inner nuclear layer to the inner plexiform layer. Ultrastructurally, the antigen was localized to cisternae within horizontal cell somata, along tubulovesicular structures in dendrites, and in the perisynaptic space encircling presynaptic terminals of the cone photoreceptor triad. These findings suggest that this PG is synthesized within the horizontal cells, transported to the terminals, and released into the extracellular spaces just proximal to the synapse. Based on the focal stain in the adjacent photoreceptor cell, it is possible that antigen is pinocytosed by this cell and is concentrated at the ribbon synapse. In Western immunoblots of retinal homogenates, MAb 6A2 recognized a heterogeneous chondroitin sulfate (CS) PG (CSPG) of approximately 400-500 kDa. After sequential enzymatic removal of CS glycosaminoglycans, a major broad band of 300-500 kDa was identified by MAb 1B5, which detects CSPGs that bear uronic acid linked to unsulfated N-acetylgalactosamine as the initial disaccharide in the CS chain. Localization of this PG around presynaptic terminals of the horizontal neuron and at the ribbon synapse suggests that it may play a modulatory and sustaining role at the synapse.

Needle aspiration cytology, immunocytochemistry, and electron microscopic study of unusual pancreatic carcinoma with pleomorphic giant cells.

Needle aspiration cytology, immunocytochemistry, and electron-microscopic findings are presented in three cases of an unusual pancreatic carcinoma in which pleomorphic giant cells formed an integral part of the tumour. All three patients were elderly males (age range 66-83 years) and had pancreatic masses. Notable cytologic features in all cases were the presence of bizarre mononucleated and multinucleated, poorly cohesive tumour giant cells, rare spindle cells, with occasional cannibalism and cytophagocytosis. Immunocytochemical study of aspirated material showed diffuse staining of cytokeratin and EMA within the tumour cells, while B 72.3 was seen as focal trace stain. Electron microscopy of aspirated material demonstrated epithelial features and these were characterised by the presence of tonofilaments and surface microvilli. Based on our findings, it is felt that the bizarre giant cells in this unusual variant of pancreatic carcinoma are of epithelial origin. The differential diagnosis of other tumours that may be associated with predominant giant cells in pancreatic aspirates is appropriately discussed.