Primary papillary epithelial tumour of the sella: expanding the spectrum of TTF-1-positive sellar lesions

AIM

To describe four novel primary epithelial tumours of the sella with papillary architecture and Thyroid Transcription Factor 1 (TTF-1) expression.

METHODS

Paraffin-embedded tissue from the four cases and recurrence of patient 1 was investigated with haematoxylin-eosin, special histochemical stains, immunohistochemistry with a broad panel of antibodies and next-generation sequencing. The ultrastructure of one tumour was studied in tissue retrieved from paraffin.

RESULTS

The lesions occurred in three females aged 20, 26 and 42 years and a male aged 49 years. They presented with signs and symptoms secondary to pituitary stalk compression. Preoperative neuroimaging documented mixed solid and cystic, enhancing sellar masses with suprasellar extension. Histologically, the tumours showed thin papillae lined by a single layer of cytokeratin and TTF-1-positive cuboidal and cylindrical cells with mildly atypical nucleus. Next-generation sequencing performed in three cases did not identify any mutations. The main differential diagnosis included metastasis from lung or thyroid carcinoma, extraventricular choroid plexus papilloma and sellar ependymoma.

CONCLUSION

We suggest the descriptive term of primary papillary epithelial tumour of the sella (PPETS) for this entity and propose that it could represent the intracranial equivalent of thyroid-like low-grade nasopharyngeal papillary adenocarcinoma. The cell of origin of PPETS remains undetermined although the intense and ubiquitous expression of TTF-1 may suggest a derivation from the infundibulum or ventricular recess. Our study expands the spectrum of sellar TTF-1-positive tumour and challenges the view that they all derive from pituicytes.

Sinistroposition of the gallbladder and the common bile duct

A left lateral bisegmentectomy was performed in a 29-year-old man presenting a primary lymphoma of the liver. Surgical exploration revealed a left-side gallbladder, located under the left lobe of the liver. During hepatic parenchyma dissection, performed strictly at the left of the round ligament and the umbilical portion of the left portal vein, common bile duct was injured. Complete separation of hepatic pedicle structures showed that the upper biliary convergence passed on the left side of the umbilical portion of the left portal vein before reaching the hepatoduodenal ligament. This case report discusses the embryological mechanism that could explain this uncommon bile duct abnormality, focusing on its consequences during left ruled lobectomy.

Histological, immunohistochemical, ultrastructural and biochemical study of human gastric composite tumor: expression of the serotonin-2B receptor by the neuroendocrine component

We report a case of a human gastric composite tumor occurring seven years after a partial gastrectomy for a low grade B cell MALT lymphoma. Histological examination of the tumor revealed two intimately intermingled components: 1. A moderately to poorly differentiated tubulo-acinar adenocarcinoma with signet-ring cells; and 2. Isolated or clustered small neuroendocrine cells without atypia expressing chromogranin A, somatostatin and/or glucagon, serotonin (5-HT) and, the 5-HT2B receptors. In addition to immunohistochemical detection, the presence of 5-HT2B receptors was shown pharmacologically through [125I]-DOI binding. Since 5-HT2B receptors have been demonstrated to have autocrine functions and, mitogenic and transforming properties, these results suggest a role of 5-HT in neuroendocrine malignant transformation. On the other hand, the expression of somatostatin and the detection by reverse transcriptase polymerase chain reaction (RT-PCR) of somatostatin receptor subtypes 2, 3, and 5, which have been shown to be involved in tumor regression, might account for the long evolution of this case (> 5 yr). This case illustrates the importance of local humoral modulation in tumor growth. Moreover, ultrastructural results favor a unique origin of the tumor cells from one amphicrine cell type.

Lipomatous polyposis of the colon with multiple lipomas of peritoneal folds and giant diverticulosis: report of a case

A case of multiple lipomatosis exclusively located in the colon is reported in a young male (33 years). It is characterized by a great number of lipomas with polyposis growth appearance, multiple lipomas of peritoneal folds, and giant diverticulosis probably caused by weakened areas of colonic wall induced by the lipomas.

Gene transfer to urethral strictures in rabbits: a preliminary report

OBJECTIVE

To assess the rationale for virus-mediated gene transfer into the urethra in vivo and in vitro, using a rabbit model, as this is an attractive approach to prevent recurrence after the endoscopic management of urethral strictures.

MATERIALS AND METHODS

Primary cultures of rabbit urethral stromal cells were infected with adenoviral and retroviral solutions carrying a nucleus-targeted beta-galactosidase (beta-Gal) reporter gene (respectively 109 and 107 plaque-forming units/mL). In addition, to mimic the human clinical situation, a model was developed of thermally induced stricture in rabbit urethra which produced fibrotic stenosis within 15 days. Using a prototype channelled balloon catheter, these strictures were endoscopically dilated and then instilled with the beta-Gal adenoviral or retroviral constructs.

RESULTS

The application of recombinant adenovirus and retrovirus harbouring a nucleus-targeted beta-Gal reporter gene to cultured rabbit urethral stromal cells resulted in a high transduction efficiency of up to 90% and 96%, respectively. Five days after infection, histochemical and immunohistochemical staining of the strictured urethrae showed a 3% rate of transfection targeted to stromal cells within the fibrosis, confirmed by polymerase chain reaction (PCR) analysis. Adjacent and distal spread of the virus was excluded by histochemistry, immunohistochemistry and PCR.

CONCLUSION

These results represent the first report of endoscopic adenovirus and retrovirus-mediated gene transfer to the urethra. Although at a low rate, transduction reached stromal cells transmurally within the induced strictures and was site-specific.

In vivo regulation of von willebrand factor synthesis: von Willebrand factor production in endothelial cells after lung transplantation between normal pigs and von Willebrand factor-deficient pigs

To evaluate the regulation of plasma von Willebrand factor (vWF) and its in situ production by endothelial cells (ECs), 12 swine leukocyte antigen (SLA)-compatible left lung transplantations were performed. Normal lungs were transplanted into 10 pigs homozygous for von Willebrand disease and into 2 normal pigs. Additionally, 1 normal pig underwent pneumonectomy, and 1 SLA-incompatible lung transplantation between normal pigs was performed. None of the transplanted animals received immunosuppressive therapy. Plasma vWF level was evaluated by ELISA and multimeric pattern. EC vWF content was assessed by immunohistochemistry. Global hemostasis was assessed by standardized ear bleeding time. Six of 12 SLA-compatible lung transplantations and the incompatible transplantation were successful and were used for the study. The functions and the viability of ECs, reflected by their ability to produce vWF and normal multimeric plasma vWF pattern, were preserved in SLA-compatible and -incompatible lung transplantations. vWF production was preserved in ECs that initially synthesized it. EC constitutive and storage pathways are modulated differently according to transplantation compatibility and severity of rejection. In SLA-compatible lung transplantations without histological evidence of rejection, the production of vWF was preserved, whereas constitutive vWF secretion appeared to be altered in cases with minor histological signs of rejection. In pigs with von Willebrand disease that were transplanted with normal lungs without sign of rejection, plasma vWF was significantly increased in an amount expected from the estimated production of a normal lung. In the transplanted normal lung, there was no vWF overexpression by the ECs and no recruitment of ECs that initially did not express vWF. In SLA-incompatible transplantation, ECs were morphologically normal with increased and blurred vWF labeling, whereas plasma vWF levels remained normal, reflecting that EC activation is associated with an increased vWF production with probable diversion to storage pathway. This model depicts the changes of EC regulation of vWF secretion in pig lung transplants. However, this model cannot be directly extrapolated to human organ transplantation because animals did not receive any immunosuppressive therapy, which may be toxic to ECs.

Phenotypic and functional characteristics of porcine peritoneal mesothelial cells

The objective of this study was to establish a technique to isolate porcine mesothelial cells (PMCs) from omental tissue and to compare them to human mesothelial cells (HMCs). The PMCs were dispersed by collagenase digestion and isolated on a Ficoll layer. Their morphologic and ultrastructural features were assessed at confluence by light and electronic microscopy, and they were characterized by immunohistochemistry using specific HMC markers. PMC proliferation was studied in the presence of growth factors platelet-derived growth factor (PDGF), epidermal growth factor (EGF) or transforming growth factors beta1, beta2, or beta3 (TGF). Fibrinolytic PMC activity was detected by zymography for tissue plasminogen activator (tPA) and by reverse zymography for plasminogen activator inhibitor-1 (PAI-1). The recalcification time of cell lysates was used to define PMC procoagulant activity, and gelatinase zymography was used to detect metalloproteinase production. At confluence, PMCs formed typical cobblestone monolayers and exhibited structural features characteristic of HMCs. Weibel Palade bodies were never seen. Specific HMC markers (HBME1, ME1, WT1) cross-reacted with PMCs. As HMCs and PMCs coexpressed cytokeratin and vimentin, and also expressed vinculin and alpha-actin. Addition of PDGF or EGF to the culture medium stimulated PMC proliferation. PMCs constitutively expressed fibrinolytic and procoagulant activity and secreted MMP9 and MMP2. The technique described in this study allows isolation of mesothelial cells from porcine omental tissue. These porcine cells exhibit a mesothelial phenotype and functional properties similar to those of HMCs. Our data warrant an evaluation of mesothelial cells as targets in several therapeutic strategies with porcine models.

Macro and microheterogeneity in normal endothelial cells: differential composition of luminal glycocalyx and functional implications

Endothelial cells (EC) are involved in various physiological and pathological processes through the expression of their surface glycoproteins. They are covered by the glycocalyx, composed of glucidic residues from cell surface membrane glycoproteins, glycoplipids and proteoglycans. Glucidic sequences can be specifically characterized by their binding to lectins. Eight lectins were used to investigate the distribution and regulation of EC surface glucidic residues in various blood vessels of adult and newborn pigs. EC lectin binding was compared to von Willebrand factor (vWF) expression as EC reference marker. Six out of eight lectins (BSI-B4, DBA, EEA, HP, MAL I and PNA) were helpful for this determination. Considering only the intensity of labelings, vWF and DBA gave the best stainings of adult pig ECs. In newborn pigs, the best labelings were obtained with EEA and MAL I. Furthermore, the distribution of lectin binding to ECs and EC vWF expression was heterogeneous depending on the EC location along vascular tree and age. Beside this macroheterogeneity this study highlights a microheterogeneity of EC lectin binding and vWF expression in situ, defined as a staining of equal intensity by individual ECs, scattered among negative ones, in a given vascular segment. EC surface sugar residues were differently modulated in newborn and adult pig ECs and differently according to EC vWF expression. The functional involvement of EC glycocalyx was reflected by EC lectin binding in the spleen and liver. This study emphasizes the high level of EC heterogeneity for various markers. The EC macro- and microheterogeneity reflect the "plasticity" or "unstability" of EC phenotypes and suggests that ECs are subject to several levels of regulation and are probably grouped in functional clusters to best adjust their functions to microenvironmental requirements. This concept must be considered in further investigations notably in in vitro studies where EC phenotype can be altered.

An experimental model of bulbar urethral stricture in rabbits using endoscopic radiofrequency coagulation

OBJECTIVES

To develop an experimental model of endoscopic urethral stricture mimicking the human clinical situation.

METHODS

Twenty-four New Zealand male rabbits were included. Eighteen animals (study group) underwent videourethroscopy with a pediatric resectoscope, and a 3 to 5-mm-long circumferential electrocoagulation of the bulbar urethra was performed, without postoperative urinary diversion. Six animals underwent the same procedure without application of electrocautery (control group). Each animal was assessed for urethral stricture on day 15 and day 30 by videourethroscopy and voiding cystogram. Among the study group, 8 animals were killed on day 15 and 10 on day 30 for histologic evaluation. All the control animals were killed on day 30 for histologic examination.

RESULTS

Nine animals (50%) in the study group developed a significant bulbar stricture (reducing the lumen by more than 50%) at day 15. Histologic examination confirmed the presence of hyalin fibrosis mutilating the urethral wall. No spontaneous improvement of the stricture was observed on day 30. None of the controls developed urethral stricture, and histologic examination showed a normal urethra in each case.

CONCLUSIONS

Endoscopic electrocoagulation of the urethral wall provides a reproducible model of stricture in the rabbit.

Ureteral gene transfer to porcine induced strictures using endourologic delivery of an adenoviral vector

PURPOSE

Direct gene transfer to the ureter is an attractive approach to prevent restenosis after endourologic management of ureteral strictures. We therefore assessed the rationale for adenovirus-mediated gene transfer in the ureter in vitro and in vivo using a porcine model.

MATERIALS AND METHODS

Primary cultures of porcine ureteral epithelial and stromal cells were infected with an adenoviral solution carrying a nucleus-targeted beta-Galactosidase (beta-Gal) reporter gene (6.5 10(8) pfu/ml.). In addition, in order to mimic the human clinical situation, we have devised a model of thermally-induced stricture in porcine ureter which produced tight fibrotic stenosis within 8 days. Using a purposely designed channelled balloon catheter prototype, these strictures were endoscopically dilated and then instilled with the same beta-Gal adenoviral construction.

RESULTS

Application of recombinant adenovirus harboring a nucleus-targeted beta-Gal reporter gene to cultured porcine urothelial and stromal cells resulted in high transduction efficiency of up to 99% and 84% respectively. Seven days after infection, X-Gal staining of the strictured ureters demonstrated transfection up to 2 mm. depth within the fibrosis, confirmed by polymerase chain reaction (PCR) analysis. Adjacent and distal spread of the virus was excluded by histochemistry (X-Gal staining) and PCR.

CONCLUSION

This data represents the first report of adenovirus-mediated gene transfer to the ureter. It remained site specific by endourologic retrograde clinically applicable techniques.

[Hepatic brucelloma: 2 cases and a review of the literature]

We report two new cases of hepatic brucelloma in addition to the 22 previously reported cases in the literature. Our analysis of these cases reveals certain characteristics. Hepatic brucelloma is a rare localization that follows previously undetected acute brucellosis. Brucelloma is a result of caseification of a granulomatous reaction induced by persistent Brucella in macrophages. Clinical manifestations can mimic malignant liver tumors or pyogenic, amebic liver abscess. Diagnosis is based on the association of characteristic imaging features (central calcification and peripheral necrotic areas), positive serology and hepatic granulomas. Brucella is rarely isolated in the blood or liver. Awareness of this clinical variant can prevent unnecessary laparotomy. Treatment should begin with rifampicine (900 mg per day) and doxycyclin (200 mg per day) for 3 months. If medical treatment is unsuccessful, percutaneous or surgical drainage should be performed. A cure should be achieved in all cases.

Thrombotic carotid megabulb: fibromuscular dysplasia, septae, and ischemic stroke

The proximal internal carotid artery is most commonly spared in cerebral fibromuscular dysplasia. The authors report the cases of three young black patients with stroke and carotid megabulbs with fibrous components, two of whom had superimposed thrombi.

Thermal radiofrequency induced porcine ureteral stricture: a convenient endourologic model

PURPOSE

To establish a reliable model of iatrogenic ureteral stricture mimicking the human clinical situation in order to experiment with new site-specific endourologic treatment concepts.

MATERIALS AND METHODS

After cystoscopic insertion of a 7F right ureteral catheter, we induced external thermal radiofrequency injury to the right upper third ureter at low power setting (10 W) using an open surgical approach in 13 pigs. Three pigs considered as controls underwent the same procedure without application of electrocautery. All 16 animals were initially assessed at 8 days; 3 study animals and the 3 controls were followed for 6 weeks.

RESULTS

No control animals had strictures. Significant upper third ureteral strictures with marked hydronephrosis where achieved in all study animals after a mean interval of 9 days, as evidenced by ultrasound examination and retrograde ureteropyelography. Endoscopic retrograde access to these strictures was always possible (mean length 1.4 cm.). Histologic examination displayed severe disorganization of the muscular layer by dense fibrosis composed of collagen bundles with few scattered fibroblasts. No spontaneous improvement of the stricture was observed in the 3 animals reassessed at 6 weeks.

CONCLUSIONS

Externally applied radiofrequency energy to porcine ureter provides a reproducible model of fibrous stricture resembling its clinical counterparts.

[The intratesticular leiomyoma: an unusual location. Report of a case]

Intratesticular location of leiomyoma is unusual. A single case has been published in the literature. We report a case of what we consider to be an intratesticular leiomyoma, with a description of its pathology, a discussion of its differential diagnosis and histogenesis.

Color velocity imaging and power Doppler sonography of the gallbladder wall: a new look at sonographic diagnosis of acute cholecystitis

OBJECTIVE

Color velocity imaging is a color sonographic technique that uses data contained in gray-scale B-mode image scan lines to determine blood flow velocity. We prospectively determined if color velocity imaging and power Doppler sonography can be used to differentiate acute from chronic cholecystitis. We analyzed the potential role of using these two color imaging techniques as an adjunct to conventional gray-scale sonography to differentiate acute from chronic cholecystitis.

SUBJECTS AND METHODS

One hundred twenty-nine patients with acute right upper quadrant pain or clinically suspected cholecystitis underwent color velocity imaging and power Doppler sonography of the gallbladder as an adjunct to gray-scale sonography. Morphologic criteria were analyzed on gray-scale sonography, and the presence of flow within the gallbladder wall was assessed with color velocity imaging and power Doppler sonography. Imaging findings were compared with pathologic findings in the 50 patients who underwent cholecystectomy and with clinical and biologic findings in the 79 patients who did not undergo cholecystectomy.

RESULTS

Twenty-two patients had surgically proven acute cholecystitis, 28 patients had surgically proven chronic cholecystitis, and 79 patients had no gallbladder disease. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of gray-scale sonography for revealing acute cholecystitis were 86%, 99%, 92%, 87%, and 97%, respectively. Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of color velocity imaging and power Doppler sonography for revealing acute cholecystitis were 95%, 100%, 99%, 100%, and 99%, respectively.

CONCLUSION

The accuracy of color velocity imaging and power Doppler sonography in revealing acute cholecystitis is significantly greater than the accuracy of gray-scale sonography.

Role of plasma and platelet von Willebrand factor in arterial thrombogenesis and hemostasis in the pig

To evaluate the relative role of plasma and platelet von Willebrand factor (vWF) pools in hemostasis and arterial thrombogenesis, pigs with vW disease (vWD) were injected with vWF concentrate and/or grafted with bone marrow from a normal pig. Hemostasis was assessed by measurement of ear immersion bleeding time, factor VIII (FVIII) activity, and plasma and platelet vWF antigen levels. The thrombotic process was explored at 650 s(-1) and 1600 s(-1) in an ex vivo cylindrical perfusion chamber. Pigs with vWD exhibited a prolonged bleeding time (>30 minutes) compared with normal pigs (<5 minutes); in addition, they showed normal platelet adhesion and thrombus formation at 650 s(-1) but profoundly reduced platelet adhesion and thrombus formation at 1600 s(-1). Each experiment was performed before and 3 and 24 hours after injection of vWF concentrate. In our bleeding time study, only plasma vWF restoration induced a partial but delayed correction (24 hours postinjection), which was correlated with the highest measured level of FVIII activity. In the perfusion chamber model, restoration of plasma or platelet vWF pools resulted in similar partial correction of platelet adhesion and average thrombus size. In the perfused pigs, the maximum correction occurred 3 hours postinjection. Platelet deposition reached normal values after vWF concentrate was injected into a grafted pig. The present results suggest that when both plasma and platelet vWF levels are restored in vWD pigs, bleeding time and the thrombotic process are normalized according to different kinetics and with differing degrees of effectiveness.

Inverse immunostaining pattern for synthesized versus endocytosed alpha-granule proteins in human bone marrow megakaryocytes

The time of appearance and pattern of expression of several alpha-granule proteins, von Willebrand factor (VWF), fibrinogen and immunoglobulins (Ig) were examined and compared in human bone marrow megakaryocytes (MK) using an immunocytochemical approach. VWF is synthesized by immature MK, whereas it has been shown that fibrinogen is incorporated from the plasma into alpha-granules. The present study was undertaken in order to determine whether there are chronological and morphological differences in the expression of VWF and fibrinogen in vivo in human MK. Seven paraffin-embedded biopsies of normal human bone marrow were labelled with specific antibodies for VWF and for fibrinogen, detected by the alkaline phosphatase anti-alkaline phosphatase (APAAP) method. and analysed by immunomorphometry. We found a clear, statistically significant. difference in the labelling pattern of VWF and fibrinogen. The expression of other endocytosed alpha-granule proteins, immunoglobulins G and A, was therefore studied in bone marrow MK from two patients with multiple myeloma, one with monoclonal IgG and one with monoclonal IgA. The immunostaining pattern was similar to that of fibrinogen and different from VWF, and characteristic of endocytosed alpha-granule proteins. This study demonstrates that: (i) immunohistochemical staining of MK alpha-granules proteins distinguishes the peripheral cockade distribution pattern of endocytosed protein from the perinuclear pattern of endogenously synthesized proteins; (ii) VWF is present in human bone marrow MK when fibrinogen is not yet detectable: (iii) VWF synthesis ceases while fibrinogen is still being incorporated: (iv) immunoglobulins can be detected in MK cytoplasm, with a staining pattern resembling that of fibrinogen.

Bone marrow involvement by disseminated toxoplasmosis in acquired immunodeficiency syndrome: the value of bone marrow trephine biopsy and immunohistochemistry for the diagnosis

A bone marrow biopsy was performed on four patients with acquired immune deficiency syndrome (AIDS) for a long-running course fever of unknown origin associated with a recent pancytopenia. In the four cases, striking histological similarities, such as interstitial edema, foci of necrosis and only few scattered or clustered histiocytes, were found. Near or in the foci of necrosis, free forms, and pseudocysts of Toxoplasma gondii were observed not only in the cytoplasm of macrophages and of some granulocytes, but also within megakaryocytes. No sign of other parasitic, bacterial, or fungus infection has been found. The diagnosis was confirmed by immunohistochemistry in the four cases and ultrastructural examination in one case. This case study stresses the importance of bone marrow histological changes for the diagnosis of severe toxoplasmosis in AIDS patients and particularly the localization of T gondii within the cytoplasm of megakaryocytes.

Multiple lymphomatous polyposis of the gastrointestinal tract. An extensive histopathologic and immunohistochemical study of 12 cases

BACKGROUND

Multiple lymphomatous polyposis (LP) is a rare entity, characterized by multiple polypoid tumors involving several segments of the gastrointestinal tract.

METHODS

In this large retrospective series of 12 patients with LP, histologic and immunohistochemical features were investigated from patients with multiple biopsy samples from each site (500 gastrointestinal biopsies). Immunohistochemistry was performed on paraffin embedded biopsies from 12 patients and on frozen tissue biopsies from 8 patients, for each of whom at least two different anatomic sites were studied.

RESULTS

Histologic features always were characterized by nodules located in mucosa and submucosa composed of lymphomatous, small cleaved cells. B-cell phenotype of the neoplastic cells was the same phenotype as adult mantle-zone cells or fetal follicle cells (frequent coexpression of surface IgM and surface IgD, and weak expression of CD5, CD35+, CDw32+, and CD23-). Tested cases expressed bcl-2. Five to 20% of LP cells were positive for the monoclonal antibody Ki-67. Five patients died within 5-32 months after diagnosis. Frequent extradigestive sites were also identified. There were two unique findings: five cases with digestive tract lymphoepithelial lesions (LEL), and one secondary transformation to large B-cell malignant lymphoma.

CONCLUSIONS

To the authors' knowledge, this is the largest series so far of LP studied with immunohistochemistry on frozen sections. Mantle-cell B cell phenotype of the nodular monotonous, small cleaved cells is confirmed. This entity may be classified as mantle-cell lymphoma with a similar aggressive clinical course, and treated as a high grade B-cell lymphoma. The authors know of no such LEL that has been reported previously, and secondary transformation has been described only briefly in one case.

Multiple lymphomatous polyposis of the gastrointestinal tract. An extensive histopathologic and immunohistochemical study of 12 cases

BACKGROUND

Multiple lymphomatous polyposis (LP) is a rare entity, characterized by multiple polypoid tumors involving several segments of the gastrointestinal tract.

METHODS

In this large retrospective series of 12 patients with LP, histologic and immunohistochemical features were investigated from patients with multiple biopsy samples from each site (500 gastrointestinal biopsies). Immunohistochemistry was performed on paraffin embedded biopsies from 12 patients and on frozen tissue biopsies from 8 patients, for each of whom at least two different anatomic sites were studied.

RESULTS

Histologic features always were characterized by nodules located in mucosa and submucosa composed of lymphomatous, small cleaved cells. B-cell phenotype of the neoplastic cells was the same phenotype as adult mantle-zone cells or fetal follicle cells (frequent coexpression of surface IgM and surface IgD, and weak expression of CD5, CD35+, CDw32+, and CD23-). Tested cases expressed bcl-2. Five to 20% of LP cells were positive for the monoclonal antibody Ki-67. Five patients died within 5-32 months after diagnosis. Frequent extradigestive sites were also identified. There were two unique findings: five cases with digestive tract lymphoepithelial lesions (LEL), and one secondary transformation to large B-cell malignant lymphoma.

CONCLUSIONS

To the authors' knowledge, this is the largest series so far of LP studied with immunohistochemistry on frozen sections. Mantle-cell B cell phenotype of the nodular monotonous, small cleaved cells is confirmed. This entity may be classified as mantle-cell lymphoma with a similar aggressive clinical course, and treated as a high grade B-cell lymphoma. The authors know of no such LEL that has been reported previously, and secondary transformation has been described only briefly in one case.

Primary bilateral B-cell renal lymphoma: a case report and review of the literature

Renal lymphoma is commonly secondary to lymphomatous infiltration of the kidneys in disseminated lymphoma and advanced stage IV disease. We describe a 57-year-old white woman presenting with an acute renal failure due to a bilateral "primary" B-cell lymphoma infiltration of the kidneys. The diagnosis of the lymphoma was made by renal biopsy. The striking feature observed was a destructive infiltration of the kidney by a malignant B-cell lymphoma that left the renal capsule intact, without any sign of secondary localization on the hilar regions. Physical examination did not reveal any peripheral lymphadenopathy or hepatosplenomegaly. A bilateral infiltration of both kidneys was the only feature shown by computed tomography and renal angiography. This case raises the question of the occurrence of a primary B-cell lymphoma in a nonlymphoid organ, which was diagnosed by renal biopsy at a time when the development was exclusively renal in origin.

Comparison of popliteal lymph node responses in various strains of rats

Outbred (namely Wistar and Sprague-Dawley) and inbred (Wistar-Furth, Lewis, Fisher 344 and Brown-Norway) strains of rats were screened for their responses to reference compounds in the popliteal lymph node (PLN) assay. Streptozotocin and diphenylhydantoin gave positive responses as evidenced by increased weight and cellularity indices in all strains used whereas procainamide, isoniazid and barbital consistently gave negative responses. Although these findings overall are in agreement with previous investigations involving these compounds, the lack of marked interstrain differences in PLN responses argues against a strong immunogenetically controlled mechanism as could be assumed in presumably auto-immune reactions. The question is raised whether drug-induced side-effects predicted by the PLN assay are basically non-autoimmune as suggested by clinical and immunological findings in man.

Morphology of popliteal lymph node responses in Brown-Norway rats

The popliteal lymph node (PLN) assay has been proposed as a tool to predict in rodents those xenobiotics likely to induce autoimmune reactions in humans. To further validate this assay and to study the mechanisms involved, histologic changes in PLNs from rats injected with streptozotocin, diphenylhydantoin, pure acetone, or 50% ethanol were compared to a local graft-versus-host (GvH) reaction. This study suggests that routine histology of PLNs is instrumental to discard primary irritants. In addition, the hypothesis of a GvH-like mechanism in positive PLN responses is supported by the finding that the reference compounds streptozotocin and diphenylhydantoin produced histologic changes similar to a "true" local GvH reaction.

Primary T-cell rich B-cell lymphoma of the common bile duct

A 34-year-old woman was hospitalized for the investigation of a one-month history of intestinal disorders, gastric heaviness and transitory icteric episodes. Extensive clinical investigations suggested the diagnosis of gall bladder carcinoma or sclerosing cholangitis. At laparotomy, the proximal part of common bile duct was markedly thickened by a white, firm, fish-flesh like tumour extending in to the cystic duct, gall bladder wall and to the liver. Histological study showed a diffuse lymphoid proliferation of the common bile duct mainly composed of small cells mixed with scattered large atypical cells. Immunohistochemistry revealed that most of the small cells expressed T-cell markers with predominant CD 4 and alpha-beta T-cell receptors and without phenotypic gap, whereas large atypical cells showed monotypic B phenotype with co-expression of mu and delta heavy chains and light lambda chain restriction. No evidence of primary nodal lymphoma was found during extensive clinical, radiological, sonographic or scanographic examinations. Sequential chemotherapy (MACOP-B) was instituted and the patient was still alive 4 years after diagnosis. Morphological and immunohistochemistry findings fulfilled criteria for a primary high grade B-cell lymphoma (centroblastic type, Kiel classification) from common bile duct concealed by numerous small reactive T-cells, so called T-cell rich B-cell lymphoma, not previously described in this location.

Popliteal lymph node response to procainamide and isoniazid. Role of beta-naphthoflavone, phenobarbitone and S9-mix pretreatment

The popliteal lymph node assay (PLNA) was proposed for the preclinical prediction of xenobiotics-induced autoimmune reactions in humans. Among the substances so far tested in this model, procainamide and isoniazid gave negative PLNA responses despite reports of lupus syndromes in man. To confirm the hypothesis that a metabolite instead of the parent molecule is involved, rats were pretreated with phenobarbital or beta-naphthoflavone, then injected with procainamide or isoniazid. In additional groups of animals, procainamide or isoniazid were injected together with S9-mix following various incubation times. Pretreated rats had a positive PLNA response when injected with procainamide, whereas preincubation with S9-mix resulted in a positive response to isoniazid. These results further support the validity of the PLNA.

Activation of CD4+ and CD8+ lymphocyte subsets by streptozotocin in murine popliteal lymph node (PLN) test

Time-related and dose-related popliteal lymph node (PLN) enlargement and lymphocyte subset alterations owing to subcutaneous (s.c.) injection of streptozotocin (STZ) into the foot pad were determined in (C57BL/6 x DBA/2)F1 [B6D2F1] mice. Early cell activation and time-related changes in T and B lymphocyte subsets were monitored during the onset of STZ-induced lymphoproliferative reaction by flow cytometry and immunophenotyping of lymphocyte subsets stained with a panel of monoclonal antibodies. Examination of cell size and chromatin decondensing for T and B cell subsets revealed differences in their activation profiles during the early phase of STZ-induced lymph node enlargement. The kinetics of the reaction showed initial activation and proliferation of CD4+ cells associated with accumulation of CD8+ and B cells. Subsequently CD8+ cells were activated and proliferated, but there was no evidence of early or late B cell activation as shown by the lack of increase in cell size or nuclear decondensation and the low and transient synthesis of immunoglobulins. The activation characteristics for CD4+ and CD8+ cell subsets in STZ-induced node enlargement were found to be analogous with T cell activation in acute allogeneic graft-versus-host (GVH) reaction in which the F1 recipient differed from the parent at both class I and II MHC loci. Our data support a central role for T cell activation in the induction of STZ-related PLN enlargement and suggest that recirculatory host B cells can play a major role in early node enlargement.

[Phenytoin and the popliteal lymph node test in the Sprague-Dawley rat]

The detection of xenobiotics which the potential to induce autoimmune reactions is currently hardly possible. The popliteal lymph node assay initially developed in mice may prove useful in this regard. Results obtained with phenytoin in Sprague Dawley rats are presented. Single doses of phenytoin were injected into one hind footpad and the popliteal lymph node was excised and weighed 3, 7 or 10 days after injection. Only the 5 mg dose level produced a significant increase in popliteal lymph node weight, structural and cellular changes in the lymph node indicating a humoral stimulation was noticed in the males at 2 mg and in the males and females at 5 mg. These results warrant further progress in the development of this assay.

Influence of macrolide antibiotics on the chemiluminescence of zymosan-activated human neutrophils

No statistically significant changes in the chemiluminescence response of the whole blood were noted following in vitro treatment with 0, 2, 10, 25, or 50 micrograms/ml of erythromycin, josamycin, miomycin, roxithromycin, and spiramycin. These results suggest that these macrolide antibiotics are unlikely to impair the phagocytizing abilities of human neutrophils, in agreement with previous findings indicating their lack of influence upon neutrophil chemotaxis.

Sodium valproate does not alter immune competence in mice

Spleen and thymus weight, delayed-type hypersensitivity (DTH) to sheep red blood cells (SRBC), contact hypersensitivity to picryl chloride, anti-sheep red blood cell hemagglutinin titers and plaque-forming cells (PFC), resistance against experimental toxoplasmosis as well as serum total and intestinal specific IgA were investigated in Swiss mice given sodium valproate (250 mg/kg/day) orally for 21 consecutive days. Sodium valproate (SV) did not exert marked effects as only DTH to SRBC and PFC numbers were found to be slightly altered. These results suggest that SV is unlikely to alter immune competence markedly.