Canine cutaneous and subcutaneous mast cell tumours: a narrative review.

Cutaneous and subcutaneous mast cell tumours are common neoplasms in the dog. While the majority can be treated with adequate local therapy alone, a subset demonstrates a biologically aggressive behaviour associated with local recurrence or metastasis. This article reviews the diagnosis and tumour staging of canine mast cell tumours alongside treatment options and the evidence supporting their use. In addition, prognostic markers are evaluated to highlight how one can recognise mast cell tumours that may behave in a biologically aggressive manner as well as the challenges of tumours that are large, infiltrative or in locations not amenable to wide surgical excision.

Nickel-titanium shape memory alloy Memokath 051 ureteral stent for managing long-term ureteral obstruction: 4-year experience.

PURPOSE: We present our 4-year experience with the thermo-expandable shape memory alloy Memokath 051 stent (Engineers and Doctors of Copenhagen, Copenhagen, Denmark) for managing long-term ureteral obstruction. MATERIALS AND METHODS: We used a nickel-titanium shape memory alloy ureteral stent to treat 28 patients 29 to 86 years old (mean age 59.2). Ureteral obstruction was caused by malignancy in 18 cases and by recurrent benign disease in 10. A total of 37 stents were inserted from November 1996 to November 2000 using general anesthesia. Mean followup was 19.3 months (range 3 to 35). RESULTS: Upper tract decompression was achieved in all cases. Currently 15 stents are functional in 13 patients, while 8 patients died with a total of 13 functioning stents in place. In 7 patients 9 stents were removed for various reasons. There has been no radiological evidence of encrustation to date. No patient has been rehospitalized with stent related sepsis pain or hematuria, resulting in improved quality of life. CONCLUSIONS: This stent seems to provide a significant benefit over conventional Double-J (Medical Engineering Corp., New York, New York) and other metallic stents. Its remarkable thermal memory permits removal, a feature that until recently was not available in any other metallic ureteral stent. Durable and complication-free decompression of the upper tract can be achieved with the Memokath 051.

Breast volume assessment: comparing five different techniques.

Breast volume assessment is not routinely performed pre-operatively because as yet there is no accepted technique. There have been a variety of methods published, but this is the first study to compare these techniques. We compared volume measurements obtained from mammograms (previously compared to mastectomy specimens) with estimates of volume obtained from four other techniques: thermoplastic moulding, magnetic resonance imaging, Archimedes principle and anatomical measurements. We also assessed the acceptability of each method to the patient. Measurements were performed on 10 women, which produced results for 20 breasts. We were able to calculate regression lines between volume measurements obtained from mammography to the other four methods: (1) magnetic resonance imaging (MRI), 379+(0.75 MRI) [r=0.48], (2) Thermoplastic moulding, 132+(1.46 Thermoplastic moulding) [r=0.82], (3) Anatomical measurements, 168+(1.55 Anatomical measurements) [r=0.83]. (4) Archimedes principle, 359+(0.6 Archimedes principle) [r=0.61] all units in cc. The regression curves for the different techniques are variable and it is difficult to reliably compare results. A standard method of volume measurement should be used when comparing volumes before and after intervention or between individual patients, and it is unreliable to compare volume measurements using different methods. Calculating the breast volume from mammography has previously been compared to mastectomy samples and shown to be reasonably accurate. However we feel thermoplastic moulding shows promise and should be further investigated as it gives not only a volume assessment but a three-dimensional impression of the breast shape, which may be valuable in assessing cosmesis following breast-conserving-surgery.

A new thermo-expandable shape-memory nickel-titanium alloy stent for the management of ureteric strictures.

OBJECTIVE: To assess the ease on insertion, patient tolerance, undesirable side-effects, degree of encrustation and duration of upper tract decompression with a new thermo-expandable shape memory alloy ureteric stent. PATIENTS AND METHODS: From November 1996 to October 1998, 15 patients with ureteric strictures were treated with a new nickel-titanium shape-memory alloy stent, the Memokath 051 (Engineers & Doctors A/S, Hornbaek, Denmark). A total of 22 insertions were carried out. Ureteric obstruction was caused by recurrent colorectal carcinoma in four patients; two patients each with transitional cell carcinoma of the bladder, iatrogenic injury or ischaemia at the uretero-ileal anastomosis; and one patient each with metastatic lymph nodes from prostatic carcinoma, radiation-induced fibrosis, pelvi-ureteric junction obstruction, metastatic carcinoma of the vagina and extra-luminal endometriosis. The stent has a shaft diameter of 9 F and its proximal end expands to 17 F. The first three patients were treated with the original version, which expanded to 14 F. The unexpanded stent is inserted into the ureter after initial dilatation of the stricture to 12 F. The stent is expanded by injection with sterile water preheated to 50 degrees C. The procedures were carried out under a general anaesthetic and patients were allowed home the next day. The follow-up protocol included initial intravenous urography (IVU) at 6 weeks, with assessment of a mid-stream urine sample and renal function tests. These were repeated at 3-monthly intervals. Isotopic renography was performed when indicated. RESULTS: The mean (range) follow-up was 10.6 (2-21) months; there was complete relief of upper tract obstruction in all patients. No stent-related symptoms, e.g. pain, sepsis, haematuria or frequency, were noted and no encrustation has occurred so far. The stent migrated in the first three patients with the original smaller diameter of stent but decompression of the upper tracts was maintained. None of the modified wider stents have migrated. The return of peristalsis in the proximal ureter was detected during IVU. There was no apparent endothelial growth through the stent material and no re-admissions for stent-related complications. CONCLUSION: Early experience with this new stent is very encouraging. All patients have maintained satisfactory decompression of their upper tracts with no need for repeated hospitalization for stent changes. There have been no untoward side-effects so far. This stent appears to have a valuable place in the long-term management of ureteric strictures; it is probably most suited for malignant ureteric obstruction. It should be considered in the management of selected benign strictures that require long-term JJ stenting.

Multiple differentiation pathways of rat mammary stromal cells in vitro: acquisition of a fibroblast, adipocyte or endothelial phenotype is dependent on hormonal and extracellular matrix stimulation.

It has previously been shown that mammary stromal cells possess the ability to maintain a fibroblast-like phenotype or differentiate in vitro into mature adipocytes in a hormone-dependent manner. This paper reports that rat mammary stromal cells can also differentiate into capillary-like structures in vitro when cultured on a reconstituted basement membrane (RBM). The differentiation potential of mammary stromal cells was compared with that of human umbilical vein endothelial cells (HUVEC) and 3T3-L1 preadipocytes. When cultured on plastic, mammary stromal cells, 3T3-L1 and HUVEC maintained a fibroblast-like phenotype. Mammary stromal cells and 3T3-L1, but not HUVEC, differentiated into mature adipocytes when cultured in adipogenic medium. When plated on reconstituted basement membrane, all three cell types began to migrate and organize themselves into an interconnected capillary network. By 18-20 h, mammary stromal cells organized into complex, highly branched capillary-like tubules whereas 3T3-L1 cells and HUVEC formed more simple structures. Cross-sectional analysis demonstrated the presence of an internal lumen. Mammary stromal cells were unique in their ability to progressively develop into a three-dimensional, highly branched network invading the RBM surface. The network formation was enhanced by the presence of vascular endothelial growth factor (VEGF) and was inhibited by the anti-angiogenic drug suramin. Western blotting analysis demonstrated the presence of the endothelial-specific marker flk-1, as well as the presence of the tight-junction-associated protein ZO-1. Mammary stromal cell differentiation into capillary structures was not a terminal state, since these cells were still able to differentiate into adipocytes when exposed to adipogenic medium. These findings suggest that mammary stromal cells differentiate into fibroblasts, adipocytes or vascular structures in a hormone- and substatum-dependent manner, and may explain the dramatic changes in stromal composition during both normal mammary gland development and tumorigenesis.

Quantitative assessment of lung damage due to bleomycin using computed tomography.

Visual assessment and density measurements of the lung using computed tomography (CT) were made in 18 patients undergoing treatment with bleomycin for malignant teratoma of the testis. The results of both visual assessment and density measurements were compared with changes in gas transfer per unit lung volume (KCO). Visual assessment of severity of damage to the lungs caused by bleomycin is unrelated to changes in KCO but is characteristic of bleomycin damage and allows a confident diagnosis to be made. Quantitative density measurement by CT, however, is inversely related to changes in KCO and may therefore be used to monitor the physiological effect on the patient. Examination of the lung by CT in these patients can not only characterise and define the extent of lung damage due to bleomycin but can be used to give a quantitative measurement on which to monitor treatment.

Comparison of computed tomography and conventional radiology in the assessment of treatment response of lytic bony metastases in patients with carcinoma of the breast.

Full skeletal survey, localised radiographs and computed tomography (CT) examinations were compared with clinical assessment in the evaluation of treatment response of bony metastases in 20 patients with carcinoma of the breast. Conventional radiology, skeletal survey and localised views compared poorly with clinical assessment agreeing in only 35% and 50% respectively. CT concurred with the clinical assessment in 65% of patients, particularly with respect to healing (86%). CT predicted the effect of treatment in six additional patients and this was confirmed on follow-up assessment. It is suggested that the use of skeletal surveys in monitoring treatment response is limited and that for critical evaluation of treatment CT should be the method of choice.

The chest radiograph in whooping cough.

The chest radiographs of 238 patients admitted to hospital with acute whooping cough are reviewed. Radiographic abnormalities were detected in 63 (26%) patients; pulmonary consolidation was seen in 50 (21%) patients, collapse in nine (4%) and lymphadenopathy in 22 (9%). The most common type of consolidation was peribronchial (72%). Both collapse and consolidation were commoner on the right and tended to involve the lower and middle lobes. These abnormalities were more common in those aged 1 year old or more (p less than 0.001) but no other clinical feature was found to predict those patients with an abnormal chest radiograph. Follow-up radiographs demonstrated no significant radiographic sequelae. Comparison with previous series shows a reduced frequency and change in the pattern of radiological abnormalities over the last 20 years.

Focal sparing in fatty infiltration of the liver.

Four cases of focal sparing in otherwise diffuse fatty infiltration of the liver are reported. The characteristic features are described as shown at sonography, computed tomography (CT) and scintigraphy. It is emphasised that, with ultrasound, if the increased echogenicity of the majority of the liver is not appreciated, then the area of normal hepatic parenchyma may be misinterpreted as a pathological hypoechoic lesion.

Unusual thoracoabdominal sites of metastases in testicular tumors.

Testicular tumors spread in a predictable manner to lymph nodes in the paraaortic chain and then to supradiaphragmatic nodes in the mediastinum and supraclavicular fossae. The most common sites of extranodal disease are the lungs and liver. In a series of 650 patients with testicular tumors who underwent CT examinations unusual sites of thoracoabdominal metastases were demonstrated in 20 patients (23 sites). The sites involved were kidney (six patients), adrenal glands (four patients), inferior vena cava (four patients), muscle (three patients), spleen (two patients), and stomach, pelvic cyst, seminal vesicles and prostate, and pericardium (one patient, each site). Renal metastases were either of soft-tissue density (four patients) or cystic (two patients). Cystic metastases were also identified in the spleen in two patients and in the adrenal gland in one patient. In three of the patients with inferior vena cava involvement, thrombus was seen to extend above the nodal mass over several centimeters. Metastases were demonstrated in the psoas, iliac, and middle gluteal muscles. These were separate from retroperitoneal nodal masses. The ability of CT to identify sites of metastases, which may remain undiagnosed by conventional staging procedures, is emphasized.

The accuracy of CT scanning prior to para-aortic lymphadenectomy in patients with bulky metastases from testicular teratoma.

The accuracy of CT scanning prior to para-aortic lymphadenectomy was assessed in 108 patients with metastatic testicular teratoma. In 106 its presence was confirmed by surgery. The site was accurately predicted in 95%. A good correlation (P less than 0.0025) was found between mean tumour cross-sectional area assessed by CT scanning and that measured in the excised pathological specimens.

Bleomycin-related lung damage: CT evidence.

Computed tomography (CT) examinations of the chest were evaluated in 100 patients treated with bleomycin. The CT findings were compared with those of conventional chest radiographs and lung-function tests. Lung damage due to bleomycin was detected in 38% of patients by CT, while damage was detected in only 15% by radiography. Changes in appearance seen on CT scans due to bleomycin damage were compared with measurements of lung volume and gas transfer per unit lung volume. There was good correlation between severity of damage shown on CT scans and changes in lung volume (P less than 0.01). Gas transfer capabilities were reduced in most patients regardless of changes observed on CT scans. Sequential CT studies showed that complete resolution of bleomycin damage may occur within 9 months in patients with minor or moderate damage. Residual abnormalities were seen in all patients with severe damage. CT can confirm lung damage in a patient with suspected toxicity but a normal chest radiograph and can define the anatomic extent of disease in a patient with an abnormal lung-function test.

Ultrasound demonstration of changes in the normal portal venous system following a meal.

Eating might be expected to change vessel size within the portal venous system. The diameters of the portal and superior mesenteric veins were measured in thirteen normal individuals using B-mode ultrasound, initially fasting and then following a meal. We have shown a 50% increase in the diameter of both these vessels occurring between thirty minutes and one hour after a meal. The significance of this is discussed.