[CEUS as a tool to uncover an unusual cause of obstructive jaundice]

Aneurysms within the visceral arteries are rare. Among these, aneurysms of the splenic artery occur most frequently followed by aneurysms of the hepatic arteries. An early diagnosis is easily missed and almost all patients become symptomatic with an acute rupture associated with high mortality. Here we demonstrate the case of a 76-year-old patient who presented with acute upper abdominal pain accompanied by a single episode of vomiting and pyrexia of 39 °C. Laboratory results presented the picture of an obstructive jaundice without evidence for accompanying pancreatitis. Inflammatory markers were within normal limits at onset, but increased dramatically within the next few days. An acute calculous cholecystitis was diagnosed on abdominal ultrasound whereas gastroscopy revealed no relevant changes. Computed tomography was suspicious for pancreatitis of the head with obstruction of the bile duct. Choledocholithiasis was ruled out by ERCP, but symptoms persisted despite papillotomy. Due to raising inflammatory markers and an ongoing impairment of the patients condition, an abdominal CT scan was repeated which revealed the suspicion of a ruptured aneurysm of the common hepatic artery. At the time of transferral we were able to confirm the diagnosis by contrast-enhanced ultrasound and angiography. The patient was immediately forwarded to surgery due to lack of satisfactory endovascular procedures. In summary, the patient suffered from a ruptured spurial aneurysm of the right gastric artery thereby obstructing the common bile duct. Beside CT scans and angiography, this case documents a pivotal role for contrast-enhanced ultrasound in the work-up of visceral artery aneurysms.

[A comparison of the use of electrochemical treatment and radio frequency ablation in porcine liver]

BACKGROUND

Radiofrequency ablation (RFA) and electrochemical treatment (ECT) are competing methods of intrahepatic ablation. We compared RFA and ECT in a perfusion model and in vivo in pigs.

MATERIAL AND METHODS

Twenty-seven fresh porcine livers were obtained from a slaughterhouse and placed ex vivo into a perfusion model. RFA or ECT electrodes were inserted under ultrasound guidance in perivascular locations at a distance of 10 mm from a portal vessel. A total of 83 areas of ablation were created. In vivo ablations were performed at perivascular sites in 10 laparotomised pigs. Four areas of ablation were created per liver using RFA or ECL. Inflammatory parameters, liver values and cytokine levels were determined before and after surgery and on days 1, 3 and 7 after surgery. On day 7, the livers were harvested and specimens were analysed histo-logically by independent experts.

RESULTS

In 29% of 59 ex vivo RFA ablations, the target temperature was not reached and the procedure was discontinued. Intact hepatocytes were detected in close proximity to 70 % of the vessels within necrotic areas. In 24 ECT applications, treatment time depended on the charge delivered and ranged between 50 min at 150 coulombs (C) and 200 min at 600 C. The pH level was 0.9 at the anode and 12.2 at the cathode. ECT always led to complete perivascular necrosis and vessel wall destruction. The animals had an in vivo -median weight of 39.5 kg. Neither RFA nor ECT caused major complications such as bleeding, bile leaks or abscesses. Treatment time was 67 min (200 C) for ECT and 12.4 min for RFA. In 73% of the cases, RFA led to incomplete perivascular areas of necrosis. ECT induced complete perivascular necrosis and vessel wall destruction. On day 1 after surgery, both ECT and RFA were associated with a significant increase in monocyte, C-reactive protein and aspartate aminotransferase levels. Leukocyte counts were elevated only after ECT, bilirubin levels only after RFA. There were no significant differences in interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and IL-1β.

CONCLUSION

Both RFA and ECL are safe methods of intrahepatic ablation. As a result of a heat sink effect of blood flow in nearby vessels, RFA leads to incomplete necrosis in perivascular sites both ex vivo and in vivo. ECT has the disadvantage of long treatment times but the advantage of lower costs since the platinum electrodes are reusable. Without a reduction in liver perfusion, the central application of RFA in close proximity to vessels should be considered problematic.

[Current state of laparoscopic hepatic surgery: results of a survey of DGAV-members]

BACKGROUND

To date laparoscopic hepatic surgery is only common in a few centres for a specific selected patient group. The intention of this survey was to estimate the current state of affairs for laparoscopic hepatic surgery in Germany at 2008.

MATERIALS AND METHODS

A questionnaire was prepared and sent out by e-mail in May 2009 to the members of the DGAV (German Society of General and Visceral Surgery). The feedback was evaluated anonymously.

RESULTS

A total of 181 answers were received by 31st July 2009 (return rate of 15.9%). The return rate of basic and standard care hospitals was 9.2%, specialized hospitals 23.6%, hospitals with maximum care 50% and university hospitals had a return rate of 71.9%. The question whether laparoscopic hepatic surgery had been performed in 2008 was answered with YES by 125 (69.1%) and NO by 54 (29.8%) members. The number of laparoscopic hepatic surgery interventions (laparoscopic ultrasound, laparoscopic radiofrequency ablation and resection) in 2008 was given as more than 50 by 4 (2.2%) hospitals, between 20 and 50 by 11 (6.1%) hospitals, between 10 and 20 by 23 (12.7%) hospitals, between 5 and 10 by 45 (24.9%) hospitals and between 0 and 5 by 54 (29.8%) hospitals. In 2008 the frequency of laparoscopic ultrasound during intraoperative staging to confirm the diagnosis ranged from 2 to 250, whereby 96.4% of the hospitals had less than 50 and only 2 hospitals (2.7%) had 211 and 250 examinations, respectively. 50 hospitals carried out laparoscopic radiofrequency ablation (RFA). 69 (38.1%) of the interviewed hospitals reported hepatic laparoscopic resections (n=551).

CONCLUSION

Laparoscopic liver surgery has been done in Germany in patients with benign or malignant liver lesions. Pure laparoscopy is the most common access. Atypical resections are the primarily indication followed by left lateral resections. All further types of resection have been done in a very small number. Laparoscopic liver surgery has been performed in all types of hospitals.

Prototype of an online navigation system for laparoscopic radiofrequency ablation

BACKGROUND/AIMS

Laparoscopic Radiofrequency-ablation is a safe and effective method for tumor destruction in patients with unresectable liver tumors. However, accurate probe placement using laparoscopic ultrasound guidance is required to achieve complete tumor ablation. After development and evaluation of laparoscopic navigation tools for radiofrequency ablation, we are now presenting a prototype of a navigation- and documentation-system for laparoscopic RFA.

METHODOLOGY

An image-guided surgery system for laparoscopic liver treatments (LapAssistent) based on a 3D-navigation scene was developed. A laparoscopic ultrasound probe and a RFA needle could be navigated using an electromagnetic tracking system. The system was studied using a perfused tumour-mimic-model of a porcine liver.

RESULTS

The study showed that laparoscopic ultrasound-guided navigation is technically feasible. The system enables the surgeon to intraoperatively update the three-dimensional planning data in case of new findings. The RFA needle could be placed accurately in a targeted tumour with a targeting error ranging from 5 - 7 mm, even out of the ultrasound plane. In case of multiple tumours lying in close spatial relationship, the documentation module helps to keep track of the already ablated tumours and those that still need to be treated.

DISCUSSION

Laparoscopic radiofrequency ablation requires advanced laparoscopic ultrasound skills for accurate placement of the RFA probe. The system adds benefit to laparoscopic RFA enabling the surgeon to place the needle accurately inside the targeted tumours using the navigation scene. The possibility to update the three-dimensional model with new intraoperative findings enables the surgeon to adapt to a new intraoperative situation.

Cell-free supernatants of Escherichia coli Nissle 1917 modulate human colonic motility: evidence from an in vitro organ bath study

Abstract Clinical studies have shown that probiotics influence gastrointestinal motility, e.g. Escherichia coli Nissle 1917 (EcN) (Mutaflor) proved to be at least as efficacious as lactulose and more potent than placebo in constipated patients. As the underlying mechanisms are not clarified, the effects of EcN culture supernatants on human colonic motility were assessed in vitro. Human colonic circular smooth muscle strips (n = 94, 17 patients) were isometrically examined in an organ bath and exposed to different concentrations of EcN supernatants. Contractility responses were recorded under (i) native conditions, (ii) electrical field stimulation (EFS), (iii) non-adrenergic non-cholinergic conditions, and (iv) enteric nerve blockade by tetrodotoxin (TTX). As concentrations of acetic acid were increased in EcN supernatants, contractility responses to acetic acid were additionally tested. EcN supernatants significantly increased the maximal tension forces both at low and high concentrations. Neither blockade of both adrenergic and cholinergic nerves nor application of TTX abolished these effects. EFS-induced contractility responses were not altered after exposure to EcN supernatants. Acetic acid elicited effects comparable to EcN supernatants only under TTX conditions. EcN supernatants modulate in vitro contractility of the human colon. As neither partial nor TTX blockade of enteric nerves abolished these effects, EcN supernatants appear to enhance colonic contractility by direct stimulation of smooth muscle cells. Active metabolites may include other substances than acetic acid, as acetic acid only partially resembled the effects elicited by EcN supernatants. The data provide a rationale for therapeutical application of probiotics in gastrointestinal motility disorders.

Prototype of an intraoperative navigation and documentation system for laparoscopic radiofrequency ablation: First experiences

AIMS

Laparoscopic radiofrequency ablation (RFA) is an accepted approach to treat unresectable liver tumours, distinguishing itself from other techniques by combining minimal invasiveness and the advantages of a surgical approach. The major task of laparoscopic RFA is the accurate needle placement according to preoperative planning to achieve complete tumour ablation. This study investigates the value of an image-guided surgery system to accomplish this task.

METHODS

An image-guided surgery system for laparoscopic liver treatments (LapAssistent) based on a 3D-navigation scene was developed. A laparoscopic ultrasound probe and a RFA needle could be navigated using an electromagnetic tracking system. The system was studied using a perfused tumour-mimic-model of a porcine liver. Navigating the RFA needle, the tumours were ablated.

RESULTS

The system enables the surgeon to intraoperatively update the three-dimensional planning data in case of new findings. The RFA needle could be placed accurately in a targeted tumour, even out of the ultrasound plane. In case of multiple tumours lying in close spatial relationship, the documentation module helps to keep track of the already ablated tumours and those that still need to be treated.

CONCLUSION

The system adds benefit to laparoscopic RFA enabling the surgeon to place the needle accurately inside the targeted tumours using the navigation scene. A manual alignment of the preoperative data to the physical space produces a feasible result for a restricted region. A precise measurement of the accuracy of this process has to be done. The possibility to update the three-dimensional model with new intraoperative findings enables the surgeon to adapt to a new intraoperative situation. Furthermore the possibility to mark ablated tumours helps to keep track of the operation plan.

Frühergebnisse nach laparoskopischer Operation bei Morbus Crohn

INTRODUCTION

During the last years laparoscopic surgical procedures are used more frequently in benign bowel diseases like Crohn's disease. We are reporting early results of laparoscopic procedures in Crohn's disease at our hospital.

PATIENTS AND METHOD

From 1994 to 2003 54 patients (20 male and 34 female) underwent laparoscopic colonic and small bowel surgery in Crohn's disease. The mean age was 32 years (range: 16 to 55 years).

RESULTS

Complications occurred in 6 patients (11.1 %). 3 patients needed a laparotomy. One computed tomography puncture was performed due to a hematoma. The remaining patients are treated successfully non-operatively. No patient died during the perioperative period. The mean operating time was 152 minutes (range 35 to 360 minutes) and the mean postoperative stay in hospital was 10 days (range 6-35 days). 0.2 blood cell concentrates were needed per operation (range 0 to 6), on average. The patients needed no analgesics after the 5 (th) day (range 1 to 13 days), got liquid diet on the 2 (nd) (range 0 to 6 days) and solid diet on the 3 (rd) day after surgery (range 1 to 14 days).

DISCUSSION

Laparoscopic surgery in Crohńs disease is safe when performed by an experienced surgeon. The laparoscopic procedure results in a better cosmetic result, while the longer operating time is the mean disadvantage. There are low complication rates during the early postoperative period.

[Blunt trocar with modified tip for open laparoscopy]

A blunt trocar for open laparoscopy is presented. Its modified design leads to better visual control of the trocar tip during insertion. Thus the risk of misplacement of the trocar is reduced.

Prognostic significance of free gastrointestinal tumor cells in peritoneal lavage detected by immunocytochemistry and polymerase chain reaction

AIMS

The aim of our study was to identify tumor cells in peritoneal lavage comparatively with immunocytochemistry (ICC) and half-nested reverse transcriptase-polymerase chain reaction (RT-PCR) using carcinoembryonic antigen (CEA) as marker and to evaluate their prognostic significance.

PATIENTS AND METHODS

In 75 patients who underwent surgery for a carcinoma of the colorectum (n=49), stomach (n=17) or pancreas (n=9) and 13 patients with an abdominal aortic aneurysm (control group) the abdomen was irrigated with saline solution immediately after laparotomy. Cells were separated by Ficoll-density centrifugation and divided into 2 equal volumes for ICC and RT-PCR. For ICC cells were spun onto slides by cytospin centrifugation and stained with a monoclonal antibody (mab) against CEA using the APAAP method. For RT-PCR total RNA was extracted from the cells, transcribed into cDNA and amplified with CEA-specific primers. Lavages of 13 patients with an abdominal aortic aneurysm and blood samples of 6 healthy donors served as controls.

RESULTS

Immunostained tumor cells were found in peritoneal lavage in 23% (17/75) of all patients, whereas 63% (47/75) of patients gave a positive result by RT-PCR analysis. In the control group (n=13) no patient presented with tumor cells in ICC, however 5 of 13 (38%) showed amplified CEA-mRNA by RT-PCR, and so did one of six blood samples. Using ICC technique, we found significant correlations between detection rates and pT-, pN-, pM-categories as well as tumor stage. On the contrary, by RT-PCR significant correlations were observed only between pT- and pM-categories and detection rates. Detection of tumor cells in peritoneal lavage with both techniques was associated with poor prognosis. Moreover, these tumor cells are an independent prognostic factor and may have an influence on the development of peritoneal carcinomatosis.

CONCLUSION

ICC is a useful method for detection of tumor cells in peritoneal lavage. In contrast, half-nested RT-PCR cannot be recommended, as the detection rates are unproportionally high, obviously as a result of CEA-mRNA expression in nontumor cells.

[Spiral trocar--a new trocar concept]

INTRODUCTION

We would like to introduce a new trocar technique for minimal invasive surgery. The new trocar is a spiral whose coil becomes ever increasingly stronger towards the centre. Because of this, there is a smooth transition between spiral, screw and rod. The outer diameter remains the same. The spiral-trocar is screwed through the abdominal wall like a corkscrew. Because of this, the primary channel of puncture runs spirally. Furthermore, the channel is dilated and centralised so that the trocar's rod together with its sleeve can be pushed through the abdominal wall. This trocar design demonstrates the following advantages: The trocar can be screwed through the abdominal wall in a controlled manner without having to apply axial pressure. This prevents any unintentional perforation of organs. Because different layers of the tissue are penetrated at different places, they overlap, thus sealing one another after removal of the sleeve. The puncture channel was minimal, thus leaving very little risk of trocar site hernia.

METHODS

The spiral-trocar was examined and compared with other types of trocars in vivo and vitro.

RESULTS

During these tests, the spiral-trocar demonstrated a high level of safety and good usability.

DISCUSSION

The spiral-trocar is an easily cleanable, reusable product without a mechanical sealing device and can be used together with most sleeves. This makes it very cost effective.

Identification of proteins in human prostate tumor material by two-dimensional gel electrophoresis and mass spectrometry

Protein patterns in cells collected from benign prostatic tissues and prostate carcinomas were analyzed using two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Polypeptide expression was evaluated by computer-assisted image analysis (PDQUEST). Proteins expressed by prostate tumors were identified via in-gel digestion and subsequent matrix-assisted laser desorption/ionization mass spectrometry. In addition to cytoskeletal and mitochondrial proteins, a 40-kDa protein was identified as prostatic acid phosphatase (PAP). PAP expression decreased approximately twofold between benign and malignant tissue. Increased expression of heat shock protein 70 and decreased expression of tropomyosin 1 were also observed in the malignant tissue. The analysis of prostate material by two-dimensional gel electrophoresis and mass spectrometry shows that particular proteins are of interest as markers of disease.

Polypeptide expression in prostate hyperplasia and prostate adenocarcinoma

Cells were collected from prostate hyperplasias (n = 6) and prostate carcinomas (n = 6) and subjected to two-dimensional gel electrophoresis (2-DE). The resulting polypeptide patterns were analysed with the PDQUEST computer software. Malignant tumors showed significant increases in the level of expression of proliferating cell nuclear antigen (PCNA), calreticulin, HSP 90 and pHSP 60, oncoprotein 18(v), elongation factor 2, glutathione-S-transferase pi (GST-pi), superoxide dismutase and triose phosphate isomerase. In addition, decreases in the levels of tropomyosin-1 and 2 and cytokeratin 18 were observed in prostate carcinomas compared to prostate hyperplasias. This pattern of alterations is similar to that observed in other carcinomas in our previous studies. All malignant tumors showed simultaneous alterations in 5 or more of 9 markers studied, whereas only one case of benign hyperplasia showed alterations in 5 markers. The EST-data base for prostate tumors available from NCI (CGAP) was searched for the expression of the mRNAs corresponding to proteins identified in our gels. Large differences in the relative expression of mRNAs and proteins were observed. Our data show alterations in the pattem of polypeptide expression in prostate carcinomas which are similar to those observed in other carcinomas.

[Disorders of intestinal innervation as a possible cause for chronic constipation]

The gastrointestinal tract contains the largest amount of nerve cells apart from the central nervous system constituting together with glial cells the enteric nervous system (ENS). The morphology of the ENS is characterized by intramurally located ganglionated and non-ganglionated plexus of different structure. The diversity of neurotransmitters synthesized by the different nerve cell types as well as the complex neuronal circuits establish the basis for the mediation of a coordinated intestinal motility. Subsequently abnormalities of the ENS may cause severe constipation. The most acknowledged intestinal innervation disorder represents aganglionosis (Hirschsprung's disease) characterized by the absence of intramural nerve cells and the hypertrophy of nerve fiber bundles within the affected intestinal segment. Non-aganglionic intestinal innervation disorders include intestinal neuronal dysplasia (IND), hypoganglionosis and heterotopic ganglia. The pathogenesis of intestinal neuronal malformations is mainly attributed to development disorders of the ENS, in part caused by genetic defects. Furthermore, the ENS can sustain damage during the postnatal period by ischemic, inflammatory, autoimmunological processes or neurotoxic agents. The histopathological diagnosis of intestinal innervation disorders is achieved by enzyme- and immunohistochemical methods. The examination of the ENS can be carried out on mucosal, deep submucosal or full-thickness biopsies using serial transverse sections as well as on intestinal whole-mount preparations allowing a three-dimensional demonstration and assessment of the intramural plexus. Structural abnormalities of the myenteric and submucosal plexus and an abnormal content of neurotransmitters have been considered to be responsible for primary chronic constipation. However, until now no unified pathophysiological concept has been established due to the partly contradictory findings. Therefore, an important goal in patients with chronic constipation should be a detailed quantitative and qualitative assessment of the underlying neurohistopathology. The correlation of these data with functional parameters of intestinal motility may represent an useful tool for the differential diagnostic and therapeutic considerations.

Laparoscopic ultrasonography reliably visualizes bile-duct injuries - a blind randomized porcine study

INTRODUCTION

Despite use of intraoperative cholangiography (IOC), only one-third or less of bile duct injuries that occur during laparoscopic cholecystectomy are detected at the primary operation. Therefore, there is a need to investigate other intraoperative diagnostic methods, especially laparoscopic ultrasound, for detecting bile-duct injuries.

MATERIALS AND METHODS

Detection of different bile-duct injuries by laparoscopic intraoperative ultrasonography was evaluated in a blind, randomized animal study. Fifty bile-duct injuries were created using laparoscopic techniques in 23 pigs. The number of single lesions and the order in which the injuries were created was randomly assigned. The lesions created were: (1) partial occlusion by a clip, (2) complete occlusion by a clip, (3) partial laceration, (4) transection without clips, (5) transection between clips and (6) excision between clips. In addition, there were cases without lesions. Different types of clips were used. A screening of the injuries by laparoscopic ultrasound using a flexible probe was attempted. The study was performed in a blind fashion.

RESULTS

Complete ultrasonographical imaging of the hepatic and common bile duct between its bifurcation and its insertion into the duodenum was accomplished in all 23 animals before surgery was performed. Eight cases without lesions were correctly recognized. In 48 of 49 cases, the injuries were detected (sensitivity 98%). In one instance, the injury was obvious without the use of ultrasound. Forty-four cases were correctly diagnosed and, in 12 cases, the injuries were equivocally differentiated (specificity of 100%, overall accuracy of 98.3%). There was only one false diagnosis. The different types of clips were also reliably differentiated.

CONCLUSIONS

We conclude that laparoscopic ultrasonography can reliably visualize most relevant bile-duct injuries. A standard for doing the ultrasound examination is proposed. Direct and indirect ultrasound signs of bile-duct injuries are explained.

Organization of the enteric nervous system in the human colon demonstrated by wholemount immunohistochemistry with special reference to the submucous plexus

To demonstrate the normal topography and structure of the enteric nervous system (ENS) in the human colon, the colonic wall of patients (n = 10, mean age 66.3 years), who underwent abdominal surgery unrelated to intestinal motility disorders, was submitted to wholemount immunohistochemistry. The specimens were stretched out and separated into the tunica muscularis, the outer and inner portion of the tela submucosa and the tunica mucosa. Prior to the application of the neuronal marker Protein Gene Product (PGP) 9.5, the laminar preparations were pretreated with the maceration agent KOH. The plexus myentericus was composed of prominent ganglia and interconnecting nerve fiber strands (NFS) forming a polygonal network, which was denser in the descending than in the ascending colon. Nerve cells were observed within the ganglia as well as in primary, secondary and tertiary NFS. The latter ramified into the adjacent smooth muscle layers, which contained the aganglionated plexus muscularis longitudinalis and circularis. The submucous plexus comprised three nerve networks of different topography and architecture: the delicate plexus submucosus extremus consisted of parallel orientated NFS with isolated nerve cells and small ganglia and was located at the outermost border of the tela submucosa adjacent to the circular muscle layer. The plexus submucosus externus was closely associated with the plexus submucosus extremus and composed of larger ganglia and thicker NFS. The plexus submucosus internus was situated adjacent to the lamina muscularis mucosae and formed a network with denser meshes but smaller ganglia and NFS than the plexus submucosus externus. The NFS of the aganglionated plexus muscularis mucosae followed the course of the smooth muscle cells of the lamina muscularis mucosae. The honeycomb-like network of the plexus mucosus was located within the lamina propria mucosae and divided into a subglandular and a periglandular portion. Single and accumulated nerve cells were observed within the plexus mucosus as a regular feature. The findings confirm the complex structural organisation of the ENS encountered in larger mammals, in particular the subdivision of the submucous plexus into three different compartments. PGP 9.5-immunohistochemistry applied to wholemount preparations comprehensively visualized the architecture of the intramural nerve plexus in human colonic specimens. In addition to conventional cross-sections, this technique allows a subtle assessment and classification of structural alterations of the ENS in patients with colorectal motor disorders.

Trisomy 3 is not a common feature in malignant lymphomas of mucosa-associated lymphoid tissue type

The genetic background of extranodal marginal zone B-cell non-Hodgkin's lymphoma (NHL) of mucosa-associated lymphoid tissue (MALT) type is poorly understood. In contrast to most entities of primary nodal lymphomas, few cytogenetic data are available, and gene rearrangements frequently encountered in and highly characteristic of certain entities of systemic NHL are absent in this type of lymphoma. Recently, it was suggested that MALT-type NHLs are associated with certain numerical chromosome aberrations and especially with trisomy 3. We performed an extensive study using a sensitive double (bicolor) fluorescence in situ hybridization technique for the analysis of trisomies for chromosomes 3, 7, 12, and 18 in 60 samples of low-grade and 45 high-grade MALT-type tumors. In the low-grade cases, trisomy 3 was found in a frequency of only 20%. High-grade lymphomas of MALT type were associated with trisomies 3, 7, 12, and 18 in 36, 20, 18, and 13% of the cases, respectively. Whereas no difference was encountered for trisomy 3 in primary and secondary/simultaneous high-grade lymphomas, +7 and +12 were associated with primary lymphomas, and a +18 was predominantly found in secondary/simultaneous high-grade NHL. These results challenge earlier reports describing a high frequency of +3 in low-grade MALT-type NHL and indicate a possibly different genetic evolution pattern of primary and secondary/simultaneous high-grade lymphomas of primary mucosal origin.

Localized gastric non-Hodgkin's lymphoma of high-grade malignancy in patients with pre-existing chronic lymphocytic leukemia or immunocytoma

Analyses for clonality in cases of Richter's syndrome have provided evidence for a clonal evolution of high-grade lymphoma in most patients, while in others an independent cellular clone seems to exist in the secondary neoplasm. Richter's syndrome with an isolated high-grade lymphoma of the stomach has been rarely reported in patients with pre-existing B cell chronic lymphocytic leukemia (CLL). We investigated four cases of CLL or lymphoplasmacytoid immunocytoma (LPIC) with development of a localized high-grade B cell lymphoma in the stomach. Southern blotting showed different rearrangements of the immunoglobulin light and heavy chain genes in the tumor cells of the low-grade lymphoma and the gastric tumor in two cases. Comparison of the DNA sequences of the CDR3 region of the immunoglobulin genes revealed different clones in another case. By means of chromosomal in situ hybridization, trisomy 3 was detected in two cases of high-grade lymphoma of the stomach, but not in the cells of the associated low-grade tumor. Our findings indicate that high-grade non-Hodgkin's lymphomas arising localized in the stomach of patients with CLL or immunocytoma are not clonally related to the pre-existing low-grade lymphoma and, therefore indeed, present true secondary neoplasms.