Mid-term follow-up of percutaneous access for standard and complex EVAR using the ProGlide device.

OBJECTIVES: Endovascular Aneurysm Repair is an established treatment for abdominal aortic aneurysm which requires arterial access via the groin. Most centres perform percutaneous ultrasound-guided access into the common femoral artery for delivery of the stent graft. The profile of endovascular devices necessitates large sheath sizes, therefore formal closure of the arterial puncture site is required. Various percutaneous devices are available, with data lacking on efficacy and mid-term safety profile. We present outcomes from a single centre with the Perclose ProGlide™ (Abbott Vascular Devices, CA, USA) suture-mediated system, using the well described "pre-close" technique. MATERIALS & METHODS: Data were collected from operative records and electronic medical records. Patients undergoing standard (EVAR) or complex (F/B-EVAR) aneurysm repair between March 2015 and September 2019 were included. Complications were recorded per-patient and per-groin procedure. RESULTS: 266 patients were included; 182 (68.4%) standard infrarenal EVAR, 84 (31.6%) F/B-EVAR. There were a total of 484 groin procedures performed. Intraoperative Perclose ProGlide™ success was 98.1% (per patient) or 99.0% (per groin procedure). 30-day groin complication rate was 6.1% (per patient) or 3.1% (per groin procedure). There were no pre- or peri-operative factors which predicted the occurrence of groin complications. The rate of groin complications was not related to sheath size. CONCLUSIONS: Our data support the use of percutaneous access with a pre-close technique for a variety of endovascular aneurysm repair procedures with both large- and small-bore access. The Perclose ProGlide™ system provides excellent mid-term complication-free and reintervention-free outcomes for groin procedures.

Shorter anogenital and anoscrotal distances correlate with the severity of hypospadias: A prospective study.

INTRODUCTION: Anogenital distance (AGD) is a recognised marker of in utero androgen action. OBJECTIVE: This study aimed to evaluate the relationship between severity of hypospadias and AGD. STUDY DESIGN: Boys undergoing hypospadias repair in a single tertiary centre between May 2012 and February 16 were included in the study. Anogenital distance was measured from the centre of the anus to the base of the penis, and anoscrotal distance (ASD) from the centre of the anus to the junction between the smooth perineal skin and scrotal skin. Trained paediatric urologists made all measurements using digital callipers. RESULTS: Fifty-nine boys with hypospadias and 31 age-matched controls undergoing circumcision (median age 1.37 years, range 1.01-1.96) had AGD and ASD measured under anaesthetic. The patients were divided into two groups, according to hypospadias severity: group 1 - distal penile/subcoronal/glandular (n = 40); and group 2 - perineal/penoscrotal/midshaft (n = 19). The median AGD for controls was 74.0 mm (range 53.2-87.8) and for hypospadias it was 72.3 mm (range 50.7-90.0) (P = 0.816). The median ASD for controls was 42.3 mm (range 31.0-56.1) and for hypospadias it was 39.4 mm (range 20.7-77.0) (P = 0.224). Considering severity of hypospadias, the median AGD for group 1 and group 2 was 73.7 mm (range 50.7-90.0) and 63.3 mm (range 53.6-77.0), respectively (P < 0.001). The median ASD was also higher in group 1, at 41.3 mm (range 20.7-65.0), compared to 35.2 mm (range 23.5-77.0) in group 2 (P = 0.119) (Summary Fig.). DISCUSSION: This study showed that more severe forms of hypospadias are associated with shorter AGD and ASD. These findings agree with two previous studies that identified reduced AGD in boys with hypospadias. However, these studies did not investigate an association with severity of hypospadias. As hypospadias is multifactorial, only a small proportion of cases are thought to be associated with impaired in utero androgen exposure. The shorter AGD in boys with severe hypospadias compared with mild hypospadias would indicate that AGD is a marker of the severity of androgen production. This may also suggest that less severe forms of hypospadias have a different aetiology involving a later stage of development, and that they are not the result of reduced androgen exposure in the male programming window between the 8-14 weeks gestation. CONCLUSION: This study identified that boys with more severe hypospadias are more likely to have a shorter AGD and ASD than boys with mild hypospadias. This may indicate that there is a more profound impairment of in utero androgen action in severe hypospadias.

'Targeted top down' approach for the investigation of UTI: A 10-year follow-up study in a cohort of 1000 children.

INTRODUCTION: Investigations following urinary tract infection (UTI) aim to identify children who are prone to renal scarring, which may be preventable. In 2002, in an attempt to reduce unnecessary intervention, the present institution standardised the investigation of children with a confirmed UTI. OBJECTIVE: This study aimed to identify the significance of urological abnormalities on investigations following a UTI in children, prior to the introduction of the National Institute for Health and Care Excellence (NICE) guidelines. METHODS: Clinical information on the first 1000 patients was retrieved from a prospective UTI hospital database. The follow-up period was 10 years. RESULTS: There were 180 males and 820 females (M:F = 1:4.5). The median age of presentation was 5 years (range 11 days-16 years). A renal ultrasound (US) was performed on all patients, and was normal in 93% of cases (n = 889) (see Figure). Of the 7% who had an abnormal US (n = 71), 54 were female and 17 male (M:F = 1:3). A total of 372 DMSA scans were requested and 350 attended their appointment. Of these, 278 cases (79%) were reported as normal, while 72 had an abnormality documented. Of these 72 patients with abnormalities on DMSA scan, 49 had a repeat DMSA scan: 30 demonstrated permanent scarring, while the DMSA scan became normal in 19. Sixteen of the 278 patients whose DMSA scan was initially normal had a repeat DMSA scan due to symptoms, and all scans were normal. Twelve (1.2%) patients required surgical intervention: three underwent circumcision for recurrent UTIs; three underwent endoscopic treatment of VUR; one had a PUV resection; one underwent a cystoscopy; three had a pyeloplasty for pelvi-ureteric junction obstruction; and one had a ureteric reimplantation for vesico-ureteric junction obstruction. After initial investigations and management, 936 patients were discharged from the UTI clinic: 47 of them re-presented - 40 with recurrent UTIs and seven with dysuria. Thirty-five of the 47 children who re-presented with urological symptoms underwent a DMSA scan, which showed scarring in three (6%). DISCUSSION: Only 12% of children have a significant radiological abnormality picked up on investigation following a UTI. The present investigation approach differed from the NICE guidelines, where imaging is based on patient age and characteristics of the UTI. All children had a renal US, while DMSA scans were reserved for those children <1 year of age or those with upper tract symptoms. The present protocol recommended a renal US in all children presenting with a UTI. This promptly identified those with pelvi-ureteric junction obstruction and those with PUV, who all presented >6 months of age with a single UTI and, therefore, based on the NICE guidelines would not have undergone a renal US. Of the children who re-presented with further UTIs, a significant number were found to have dysfunctional voiding. As this link is well reported, it may be appropriate to screen for this in older children at initial presentation. Only three patients, who had a US at presentation, were subsequently found to have scarring on DMSA. After 10 years of follow-up, this could represent a false negative rate of 0.3% for the screening programme. None of the girls were found to have VUR or needed any surgical intervention, which suggested that early identification of the scarring might not have altered management. Few patients required surgical intervention, all of whom were identified early. No patient who re-presented required intervention. This would suggest that the present protocol is effective at picking up abnormalities that require surgical management. CONCLUSION: This study suggested that after a childhood UTI, the liberal use of renal ultrasound and a focused 'top down' approach to investigation is likely to identify the vast majority of children who require intervention.

Balloon angioplasty as the primary treatment for failing infra-inguinal vein grafts.

BACKGROUND: We sought to evaluate the role of balloon angioplasty as the primary modality in the management of vein graft stenoses. METHODS: Patients who underwent infrainguinal vein graft bypass from January 2002 to December 2007 were enrolled into a surveillance program. Grafts which developed critical stenoses were identified and underwent urgent angiography with a view to angioplasty of the stenotic lesion. Lesions which were deemed unsuitable for angioplasty underwent urgent surgical repair. RESULTS: Four hundred and eleven grafts were followed up for a median of 19 months (range: 2-61). Ninety-six grafts (22.6%) developed critical stenosis. Twelve grafts occluded prior to repair and one was not intervened upon electively. Eight grafts underwent primary surgical repair. Seventy-six grafts underwent 99 endovascular procedures. Technical success was achieved in 60 grafts (78.9%). Of the grafts in which technical success had not been achieved, eight underwent repeat angioplasty and three were surgically repaired. Twenty-four grafts underwent repeat angioplasty for re-stenosis with a technical success rate of 71%. No difference was observed in graft patency (P=0.08) or amputation rates (P=0.32) between the grafts requiring intervention to maintain patency, and grafts which did not. Smoking [OR: 2.61 (95% CI: 1.51-4.53), (P=0.006)], diabetes [OR: 2.55 (95% CI: 1.49-4.35), (P=0.006)], renal failure [OR: 1.89 (95% CI: 1.19-3.38), (P=0.040)] and recurrent stenosis [OR: 3.22 (95% CI: 1.63-4.69), (P<0.001)] were risk factors for graft occlusion. CONCLUSIONS: Balloon angioplasty of failing infrainguinal vein bypass grafts is safe and can be performed with an acceptable medium term patency rate, albeit with a significant risk of re-stenosis which can be successfully treated in most patients using repeat endovascular intervention.

The value of vein graft surveillance in bypasses performed with small-diameter vein grafts.

We assessed the impact of preoperative diameter of the venous conduit on reintervention rate and outcome following infrainguinal vein graft bypass. Consecutive infrainguinal vein bypasses between January 2001 and December 2006 were reviewed. All patients underwent preoperative measurement of vein graft diameter (VGD). Grafts were classified into those with VGD <3.5 mm and those with VGD > or =3.5 mm. All patients were enrolled in a duplex surveillance program. The association between VGD and reintervention rate was assessed. Graft patency and amputation rates were compared. There were 377 bypasses followed up for a median of 23 months (range 8-67). VGD was <3.5 mm in 139 grafts (36.9%) and > or =3.5 mm in 238 grafts (63.1%). A higher proportion of smaller vein grafts (32.3%) required reintervention to maintain graft patency compared with larger conduits (20.2%) (chi(2) = 7.7, p < 0.001). VGD (odds ratio [OR] = 2.87, 95% confidence interval [CI] 1.63-3.81; p < 0.001), smoking (OR = 1.83, 95% CI 1.39-3.20; p = 0.02), and type of bypass (OR = 1.86, 95% CI 1.49-2.47; p = 0.02) were variables associated with higher reintervention rate. There was no difference in graft patency (p = 0.13) or amputation rates (p = 0.35) between the two groups. Use of smaller vein grafts was associated with a higher reintervention rate. Provided that these grafts are surveyed and where necessary repaired, the use of smaller vein grafts is successful and expands the availability of autogenous conduit for infrainguinal arterial reconstruction.

Fulminant necrotising enterocolitis immediately following change to low birth weight formula feeds.

INTRODUCTION: The aim of this study was to investigate how low birth weight formula (LBWF) feeds may be implicated in the pathogenesis of a particularly fulminant form of necrotising enterocolitis (NEC). MATERIALS AND METHODS: A retrospective case note review was undertaken of cases of fulminant NEC between 1997 and 2003 with particular regard to the feeding history. RESULTS: Nine preterm infants were stable and already tolerating full enteral feeds for a median of seven days prior to developing fulminant NEC within a median of 24 hours following the introduction of LBWF. CONCLUSIONS: Although fortification of feeds undoubtedly benefits many premature neonates, there may be a tendency for LBWF feeds to preempt the development of fulminant NEC. This possible temporal association between LBWF and fulminant NEC requires further investigation.

Endovascular repair of an anastomotic leak following open repair of abdominal aortic aneurysm.

This report describes the case of an early postoperative anastomotic leak following elective open repair of an infrarenal abdominal aortic aneurysm which was successfully treated by endovascular stent-grafting. A 71-year-old man underwent open tube graft repair of abdominal aortic aneurysm. Twelve days later he presented with a contained leak from the distal anastomosis, which was confirmed on CT scan. This was successfully treated with a bifurcated aortic stent-graft. This case illustrates the usefulness of the endovascular approach for resolving this rare surgical complication of open repair of abdominal aortic aneurysm and the challenges associated with the deployment of such a device within an aortic tube graft.

Development rationale for an articular surface replacement: a science-based evolution.

Hip resurfacing has an enduring appeal because of the advantages of bone conservation and maximal joint stability. However, a far from satisfactory experience with earlier resurfacing designs led to its virtual disappearance in the 1980s. The concept was reintroduced in the late 1990s. The current generation of resurfacing devices generally consisted of a large-diameter metal-on-metal articulation, the femoral components being cemented and the acetabular components utilizing various forms of cementless fixation. The encouraging medium-term results, with a follow-up of up to 8 years using the current generation of surface replacement joints, combined with favourable reports related to long-term performance of some metal bearings have led to a rapid increase in the use of such components with these devices. This trend is most marked in younger, more active patients who have expectations of restoration of lifestyle in addition to improved mobility and pain relief and in whom failure with conventional total hip replacement is much higher than previously reported with more sedentary patients. The aim of this paper is, firstly, to highlight a number of areas of improvement and, secondly, to explain how these may be addressed by making modifications to the design of both implants and instrumentation and to the surgical technique. The areas identified for improvement were tissue preservation (thinner components, and reduced steps between sizes), acetabular cup issues (fixation, insertion, and positioning), femoral component issues (design, loading, and cementation), improved bearing surface characteristics, and simplified precise instrumentation with a low-trauma surgical technique.

Deformation of press-fitted metallic resurfacing cups. Part 1: Experimental simulation.

The interference press fit of a metallic one-piece acetabular cup employed for metal-on-metal hip resurfacing procedures was investigated experimentally under laboratory conditions in the present study, in particular regarding the cup deformation. Tests were carried out in cadavers as well as polyurethane foams of various grades with different elastic moduli to represent different cancellous bone qualities. The cadaver test was used to establish the most suitable configuration of the foam model representing realistic support and geometrical conditions at the pelvis. It was found that a spherical cavity, with two identical areas relieved on opposite sides, was capable of creating a two-point pinching action of the ischeal and ilial columns on the cup as the worst-case scenario. Furthermore, the cup deformation produced from such a two-point loading model with a grade 30 foam was similar to that measured from the cadaver test. Therefore, such a protocol was employed in subsequent experimental tests. For a given size of the outside diameter of the cup of 60 mm, the cup deflection was shown to be dependent largely on the cup wall thickness and the diametral interference between cup and prepared cavity at implantation. For a relatively thin cup with a wall thickness between 2.3 mm (equator) and 4 mm (pole) and with a modest nominal diametral interference of 1 mm, which corresponds to an actual interference of approximately 0.5 mm, the maximum diametral cup deflection (at the rim) was around 60 microm, compared with a diametral clearance of 80-120 microm between the femoral head and the acetabular cup, generally required for fluid-film lubrication and tribological performances. Stiffening of the cup, by both thickening and lateralizing by 1 mm, reduced the cup deformation to between 30 and 50 microm with actual diametral interferences between 0.5 and 1 mm.

MACE or caecostomy button for idiopathic constipation in children: a comparison of complications and outcomes.

The Malone antegrade enema (MACE) and the caecostomy button (CB) are two methods of achieving colonic lavage in constipated children with faecal soiling. We reviewed our experience with the MACE and CB, aiming to compare results, complications, and outcomes. Between June 1998 and August 2002, 37 children (15 boys) underwent MACE and 12 children (9 boys) underwent CB for idiopathic constipation that had failed conventional treatment. Rectal biopsy was ganglionic in all cases. Mean age at surgery was 9.9 years for the MACE patients and 9.8 years for the CB patients. All children are under continuous review, and mean follow-up is 18 months. Statistical analysis of proportions used Fisher's exact test. Soiling stopped completely in 30 children with MACE and in 9 with CB. Occasional soiling is still present in two children with a CB and in one with MACE. One child with a CB had resumed regular bowel activity, and the CB was removed. MACE failed in 5 (14%) patients because of ineffective colonic lavage, and in one patient (3%) the appendix was replaced by a CB because of perforation of the appendicostomy. CB failed in one patient (8%) because of faecal leak around the button; the child was subsequently converted to MACE (P = >0.5). Complications requiring operative intervention were seen in 9 (24%) of the 37 patients who underwent MACE and none of the 12 patients who underwent CB (P = 0.09). The main complication requiring surgical intervention was stoma stenosis (11%). Complications not requiring operative intervention were seen in 7 (19%) patients after MACE and 11 (92%) of the 12 patients who underwent CB (P < 0.001). The MACE and CB procedures are reliable and effective with high success rates. The MACE has a higher incidence of complications requiring operative intervention. Conversely, complications not requiring operative intervention are more frequent with CB. CB is a safe and effective alternative to MACE in children with faecal soiling.

The role of the intra-aortic balloon pump counterpulsation (IABP) in emergency surgery.

Elective surgical procedures are often delayed for up to six months in patients who have suffered a myocardial infarction (MI) because of the substantial risk of re-infarction and high peri-operative mortality. The optimal management of patients who have sustained a recent myocardial infarction and who require an emergency abdominal operation, however, has yet to be defined. The use of an intraaortic balloon pump (IABP) may play a role in such patients by improving the function of the injured heart. Three cases are presented in which IABP was used in patients who had recently sustained a myocardial infarction and who required emergency abdominal surgery. A review of the literature is presented and the application of IABP in such circumstances is discussed. Although clinical experience is limited, the use of the IABP may be useful in selected patients who have sustained a recent MI and who require emergency surgery.

Prognostic value of laparoscopic ultrasound in patients with gastro-esophageal cancer.

Forty-four patients with gastro-esophageal tumors regarded as resectable by conventional staging underwent laparoscopic ultrasonography (LUS). Following LUS, seven were found to be irresectable and were managed by palliative therapies. Thirty-seven patients proceeded to surgical exploration and 36 were resected (R0 80%, R1 11%, and R2 9%). All patients were reviewed until death or for a minimum of 24 months. Patients undergoing resection had a 62% 1-year survival (median 17 months; confidence intervals, CI 6-28). LUS defined nodal status indicated a trend toward prolonged survival in the node-negative group, median 22 months (CI 5-39), compared with 13 months (CI 6-20) in the node-positive group. Disease-free survival was greater in LUS node-negative patients at 29 months (CI 23-35) compared with node-positive patients at 13 months (CI 5-21) P=0.0083. LUS staging allows prediction of the likelihood of recurrence of gastro-esophageal malignancies. This may prove useful for the appropriate allocation of patients to primary and adjuvant therapies.

Emerging trends in the management of the impalpable testis.

BACKGROUND: The management of the impalpable undescended testis is controversial. The study examines emerging trends in the management of this problem. METHODS: Two groups of boys were treated consecutively and recorded prospectively from 1974 to 1984 and from 1990 to 1998 inclusive. A consistent policy of using the preperitoneal approach for impalpable testis was adopted during both time intervals but during the second study period examination under anaesthesia and diagnostic laparoscopy were introduced to ascertain testicular presence and location. RESULTS: Some 919 boys were treated for cryptorchidism during the study period. Ninety boys in the first group (23 per cent) underwent preperitoneal explorations for impalpable testes. Anorchia was present in 18 and orchidectomy was performed in two boys. Thirty boys in the later group (5 per cent) were diagnosed as having impalpable testes. Fifteen boys underwent successful preperitoneal orchidopexy, anorchia was present in 11 and four underwent orchidectomy, carried out for high intra-abdominal testes. CONCLUSION: Examination under anaesthesia and subsequent laparoscopic assessment for all impalpable testes has reduced the need for preperitoneal exploration for the impalpable undescended testis. In this large series, division of the testicular vessels in order to secure scrotal placement of the testis was required in one instance only.

Sentinel node localization in patients with breast cancer.

BACKGROUND: Intraoperative lymphatic mapping and identification of the first draining lymph node (the sentinel node) may allow some patients with breast cancer to avoid the morbidity of formal axillary clearance. The aim of this pilot study was to establish the reliability of the technique in predicting axillary node status. METHODS: Sixty-eight consecutive patients with breast cancer, 38 undergoing mastectomy and 30 wide local excision, were included. Some 2-4 ml of 2.5 per cent Patent Blue dye was injected into adjacent breast tissue on the axillary side of the primary tumour. After 5-10 min, the axilla was explored. Blue-stained lymphatics were dissected to the sentinel node, which was removed for frozen-section examination, followed by routine histology. Formal axillary dissection was then completed. RESULTS: A sentinel lymph node was identified successfully in 56 (82 per cent) of 68 patients. Histology of the sentinel node accurately predicted axillary node status in 53 (95 per cent). There were three false negatives (5 per cent). In each case, only a single non-sentinel node was tumour positive. Sensitivity and specificity were 83 and 100 per cent respectively. CONCLUSION: This technique would allow a selective policy of formal axillary dissection in only node-positive patients; however, further experience and refinement are needed.

Continuous venous infusion 5-fluorouracil and interferon-alpha in pancreatic carcinoma.

Chemotherapy treatment for advanced pancreatic cancer is universally disappointing. Evidence suggested the possibility of improved activity of 5-fluorouracil (5-FU) in this disease when administered by continuous infusion in combination with interferon-alpha. Thirteen patients who had histologically documented stage III and IV adenocarcinoma of the pancreas were treated with 5-FU, 250 mg/m2/day by continuous infusion, in combination with interferon-alpha, 3 million units subcutaneously 3 times per week. Treatment was adjusted for toxicity and was continued until disease progression, unacceptable toxicity, or 8 weeks after a complete response. Responses were documented on two separate occasions that were separated by 4 weeks. Eleven men and two women were treated an average of 48 days. There was one responder, for a response rate of 7.7% (95% confidence interval, 0.1%-36%). The duration of response was 90 days. The median survival of the entire group was 8.3 months. Toxicity was significant, with more than 50% of patients requiring treatment breaks and dosage reductions. The most common toxicities were mucositis, hand-foot syndrome, diarrhea, and nausea. There were no treatment-related deaths. Treatment of advanced adenocarcinoma of the pancreas with continuous-infusion 5-FU and interferon-alpha is associated with significant toxicity without significant evidence of response.

Clinical and immune responses in advanced colorectal cancer patients treated with anti-idiotype monoclonal antibody vaccine that mimics the carcinoembryonic antigen.

Carcinoembryonic antigen (CEA) is expressed in a wide variety of adenocarcinomas, and it is well recognized that cancer patients are immunologically "tolerant" to CEA. The purpose of this study was to determine whether we could break immune tolerance to CEA by vaccinating patients with a monoclonal anti-idiotype antibody that is the internal image of CEA and to determine what impact this might have on patient survival. Twenty-four patients with advanced CEA-positive colorectal cancer who failed standard therapies except for two were entered into this Phase Ib trial. One patient was considered not assessable, because on the day of entering into the study, she was diagnosed with acute myelogenous leukemia. Patients were treated with 1, 2, or 4 mg of aluminum hydroxide-precipitated 3H1 anti-idiotype antibody every other week for four injections and then monthly until tumor progression was observed. Immunological monitoring included humoral and cellular idiotypic and CEA responses, and all patients were evaluated for toxicity, response, and survival. Hyperimmune sera from 17 of 23 patients demonstrated an anti-anti-idiotypic Ab3 response, and 13 of these responses were demonstrated to be true anti-CEA responses (Ab1'). The antibody response was polyclonal, and 11 mediated antibody-dependent cellular cytotoxicity. Ten patients had idiotypic T-cell responses, and five had specific T-cell responses to CEA. None of the patients had objective clinical responses, but overall median survival for the 23 evaluable patients was 11.3 months, with 44% 1-year survival (95% confidence interval, 23-64%). Toxicity was limited to local swelling and minimal pain. Anti-idiotype monoclonal antibody 3H1 that mimics CEA was able to break immune tolerance in the majority of treated patients. Overall survival of 11.3 months was comparable to other phase II data with advanced colorectal cancer patients treated with a variety of chemotherapy agents, including irinotecan, with considerably less toxicity. Although it is not clear that the vaccine itself had an impact on survival, this should be determined in a Phase III randomized trial.

A service manager model: instituting case management.

Using a service manager model as opposed to a traditional nurse case manager archetype fosters multidisciplinary team interaction. Benefits of this approach to the hospital, the staff and the patients are identified.

Interleukin 2 receptor expression and interleukin 2 localisation in human solid tumor cells in situ and in vitro: evidence for a direct role in the regulation of tumour cell proliferation.

Frozen sections of 52 human solid tumours (38 malignant and 14 benign) of varied histogenesis were immunohistochemically stained with well characterised monoclonal antibodies (MAbs) to human interleukin 2 (IL-2) and the alpha and beta chains of its receptor (R). In all malignant specimens, the tumour cells expressed the IL-2R beta subunit (p75) but not the IL-2R alpha subunit (CD25). In 36 of 38 malignant tumours examined, there was conspicuous staining for IL-2 in the tumour cell nuclei/nucleoli and perinuclear cytoplasm. In the human solid tumour cell lines G361 (melanoma), A549 (lung), MCF-7 (breast) and WiDR (colorectal), both subunits of the IL-2R appeared to be expressed, although the alpha subunit only weakly. Exogenous addition of human recombinant (r) interleukin 2 altered cell numbers in 3 of the 4 cell lines (WiDR was refractory). When grown in the absence of exogenously added rIL-2, IL-2 staining was observed in all cell lines. The pattern of distribution was similar to that exhibited by the tumour cells in situ (i.e., a nuclear/nucleolar localisation). In G361 melanoma cells, this IL-2 staining was present in proliferating cells but disappeared as the cultures approached confluence. Addition of an IL-2R beta subunit blocking antibody to growing G361 cultures (grown in the absence of rIL-2) resulted in a significant reduction in cell numbers. We propose, therefore, that the presence of immunoreactive IL-2 and IL-2R expression is characteristic of human malignant cells and that IL-2 may play a role in the autocrine stimulation of proliferation of malignant cells, such as G361 melanoma cells.