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Biomedical subjects

S K Yip

Publications and source records attributed to S K Yip.

At least 55 records · Page 3Linked to original sources
PubMed2000

Renal cell carcinoma: incidental detection and pathological staging.

In developed countries, there has been increased incidental detection of renal cell carcinoma (RCC). The incidence, pathological stage and survival of incidentally detected carcinoma in a developing country in Asia where, from 1990 to 1998, 165 renal cell carcinomas were identified. The clinical presentation, diagnostic-imaging modality employed, pathological staging and patient survival was reviewed. Incidental renal cancers included those that were diagnosed through health screening or detected incidentally through imaging studies for other conditions. The survival between these incidentally detected lesions and their symptomatic counterparts (suspected group) was compared. Sixty-four patients (39%) had their tumours detected incidentally, including 39 who were entirely asymptomatic and 25 who presented with non-specific symptoms, not initially suggestive of RCC. For the entire group, computed tomography provided the definitive diagnosis in 81% of cases. The incidental detection group had significantly smaller size of tumour (5.9 cm c.f. 7.6 cm), lower stage and lower histological grading. In particular, 78% of patients with incidental RCC had stage I or II diseases (TNM stage classification), compared with 57% of patients with suspected tumour (p < 0.05; Chi-square test). The disease free survival was significantly better for those with incidental detection (86% c.f. 66% at last follow up; p < 0.05; log-rank test) over a mean follow up period of 33 months (range 1-91). Regression analysis showed that stage of disease was the only independent variable predictive of clinical outcome. In conclusion, that significant numbers of RCC were detected incidentally. These tumours were of a lower clinical pathological stage and had a better prognosis.

Carcinoma, Renal Cell↗
PubMed2000

Clinics in diagnostic imaging (50). Leiomyosarcoma of bladder.

A 39-year-old man presented with intermittent painless macroscopic haematuria. He was subsequently diagnosed to have a high grade leiomyosarcoma of the bladder. He underwent total cystoprostatectomy and radiotherapy but died of metastatic disease five months after the initial diagnosis. Aspects of the imaging and diagnostic pathway of painless haematuria are discussed. The management of leiomyosarcomas in the urinary system is highlighted.

Adult↗
PubMed2000

Clinics in diagnostic imaging (54).

A 29-year-old man sustained a pelvic fracture and haemorrhagic shock after a road traffic accident. He underwent an exploratory laparotomy open cystostomy, and iliac artery embolisation. Subsequent antegrade cystography and computed tomography showed a complete traumatic posterior urethral rupture with a "high riding" bladder. Delayed repair of the posterior urethra was performed 6 months later with good functional outcome. The risk of urethral injury in pelvic fractures, the mechanism of injury, and the role of imaging in the diagnosis of possible urethral injury in pelvic fractures are discussed.

Accidents, Traffic↗
PubMed1999

Partial nephrectomy for renal tumours: the Singapore General Hospital experience.

From January 1991 to August 1998, 220 radical nephrectomies were performed for renal cell carcinoma (RCC). During the same period, 27 patients underwent partial nephrectomy for their renal tumours. These included 19 male and 8 female (mean age, 54; range, 35-75). Their clinical presentation, diagnostic modalities and surgical outcome were evaluated. The lesions included 18 RCCs, 7 angiomyolipomas (AMLs), 1 oncocytoma and 1 dysoncogenetic renal tumour. Only 8 patients had specific urological symptoms. Computerised tomography (CT) scan was diagnostic in 78% of cases. Tumour size ranged from 15-50 mm for RCC and 30-190 mm for AML, respectively. Operative time averaged 92 minutes (range: 35-145). The hospital stay ranged from 3 to 25 days (mean 11). Complications occurred in four cases (14.8%); there was one death (3.7%). No tumour recurrence was detected during a mean follow up of 20 months. None of the patients developed significant renal impairment. Partial nephrectomy is feasible in small RCC and some large AML, and can be offered in selected patients.

Adult↗
PubMed1999

Clinics in diagnostic imaging (36). Benign renal oncocytoma.

A 50-year-old Indian man presented with non-specific right-sided abdominal pain. Ultrasound of the abdomen demonstrated a small right renal tumour. Computed tomography showed features suggestive of a benign renal oncocytoma. This was confirmed by frozen section during surgical exploration. A partial nephrectomy was carried out. The role and limitations of imaging in the management of solid renal masses is discussed.

Adenoma, Oxyphilic↗
PubMed1999

Clinics in diagnostic imaging (38). Post-ESWL perinephric haematoma.

A 57-year-old man presented with urosepsis related to urinary calculi. He underwent multiple sessions of ESWL and developed a perinephric haematoma that was treated conservatively and monitored by serial imaging. However, the haematoma became infected, necessitating percutaneous drainage 2 months after the initial ESWL. The risk factors and sequelae of post-ESWL perinephric haematoma, as well as its diagnosis and imaging, are discussed.

Abscess↗
PubMed1999

Role of ultrasonography in screening for urological malignancies in patients presenting with painless haematuria.

The objective of this study was to determine the efficacy of ultrasonography and urography in evaluating patients presenting with painless gross haematuria for urinary malignancies. From October 1992 to March 1997, 468 consecutive patients presenting with painless gross haematureia were prospectively investigated. Ultrasonography and urography were performed independently, followed by diagnostic cystoscopy and other relevant investigations. One hundred and twenty-five urinary malignancies (26.7%) were detected in 122 patients, 85 being carcinoma of bladder (85/468 patients; 18.2%), followed by renal cell carcinoma (25/468 patients; 5.3%). Ultrasonography was significantly more sensitive (83/85; 98%) in the detection of bladder tumours, compared to urography (42/78; 54%) (P < 0.05). In the upper tract, there was no significant difference in the sensitivity of lesion detection. Ultrasonography is more sensitive than urography for diagnosing urological malignancies in patients presenting with painless gross haematuria, where carcinoma of bladder is the commonest pathology. Its utilisation as an initial screening investigation is recommended. Patients diagnosed to be suffering from carcinoma of bladder by ultrasonography should be scheduled directly and promptly for therapeutic endoscopy.

Adult↗
PubMed1999

Case report: percutaneous balloon dilatation and ureteral stenting for tuberculous renal infundibular and ureteral strictures.

A 23-year-old woman developed progressive obstructive uropathy due to multiple renal infundibular and ureteral strictures while on drug treatment for renal tuberculosis. Communication between isolated upper and mid-pole calyces, and the ureter, was established by percutaneous guidewire manipulation. The strictures were successfully managed using percutaneous balloon catheter dilatation and ureteral stenting without the need for open surgical exploration. Kidney function was preserved at one year follow-up.

Adult↗
PubMed1999

Inferior vena cava thrombectomy for renal cell carcinoma with thrombus.

Up to 10% of patients with renal cell carcinoma have intracaval neoplastic extension. The results of nephrectomy and caval cavotomy to remove the renal tumour and caval thrombus were reviewed. From September 1991 to October 1997, 16 consecutive patients (13 males, 3 females) with a mean age of 59 years (range 45 to 75 years) underwent radical nephrectomy together with cavotomy and thrombectomy (15) or caval resection (1). The tumour thrombi extended to the infrahepatic vena cava in 9 patients, intrahepatic cava in 5 and suprahepatic cava in 2. The surgical approaches included abdominal (8), right thoraco-abdominal (5) and abdominal with median sternotomy (3), respectively; cardiac bypass was not required. The mean cava clamp time was 15 minutes and the average operative time was 127 minutes (range 70 to 190 minutes). There was no operative mortality but the complication rate was 31%. The mean hospital stay was 12 days (range 7 to 23 days). Ten patients had Robson's stage IIIa disease, 4 had stage IIIc disease and 2 had stage IV disease. During a mean follow up of 20 months (range 1 to 54 months), 6 patients were alive with no recurrence and 10 patients had died of the disease. The survival of stage IIIa patients was significantly better than stage IIIc and IV patients. In summary, caval thrombectomy is associated with acceptable operative morbidity and mortality; however, advanced staged disease dictates a short survival.

Aged↗
PubMed1999

Renal cell carcinoma in patients with chronic renal failure.

It has been found that patients suffering from chronic renal failure (CRF) are prone to develop acquired cystic kidney disease, which may subsequently lead to the development of renal cell carcinoma (RCC). We reviewed 250 consecutive cases of RCC diagnosed between January 1990 and June 1998 in our department and found 19 had associated CRF (7.6%). Their clinical presentation, mode and duration of dialysis, diagnostic evaluations, pathological stage and surgical outcome were reviewed. Sixteen had CRF with chronic glomerulonephritis and 3 with adult polycystic kidney disease. Three patients were on continuous ambulatory peritoneal dialysis (CAPD), 5 were on haemodialysis (HD) and 3 had renal transplant (2 on HD, 1 on CAPD previously). The remaining 8 patients were not on renal replacement therapy at the time of diagnosis. Ten patients were asymptomatic with incidental radiological findings while 9 had specific urological symptoms, most commonly haematuria. Ultrasonography (USG) and computed tomography (CT) scan were the main modalities of imaging employed. Nine out of the 10 asymptomatic patients had suspicious lesions detected incidentally by USG. All had subsequent preoperative CT scans confirming the presence of these lesions. All patients had single focus RCC except for 1 with multi-focal disease involving both kidneys. Sixteen patients had early stage (T1 or T2) and low grade (G1 or G2) RCC. The remaining 3 patients had advanced stage (T3a or T3b) and high grade (G3) tumours. Since half of the patients were asymptomatic, USG may be a useful tool in the outpatient review of patients with CRF and allow early diagnosis and surgical treatment of early stage, low-grade tumours and therefore may have better survival.

Carcinoma, Renal Cell↗
PubMed1999

Unassisted conception with a normal pregnancy outcome in a woman with active Mycobacterium tuberculosis infection of the endometrium. A case report.

BACKGROUND: Tuberculosis of the endometrium is usually associated with infertility. Once a patient is diagnosed with endometrial tuberculosis, she is almost certain to experience infertility; in vitro fertilization and embryo transfer offer the only realistic treatment for tuberculous infertility. We describe one case of unassisted conception with a normal pregnancy outcome in a patient with Mycobacterium tuberculosis infection of the endometrium. CASE: A 34-year-old woman who suffered from 10 years of infertility was investigated in the authors' unit. She gave no significant past medical or surgical history, and initial examinations and investigations were normal. Her husband was 34 years old, and his semen analysis was normal. The patient underwent diagnostic laparoscopy, chromohydrotubation and endometrial biopsy, which showed patency of both fallopian tubes and normal pelvic organs, with no evidence of endometriosis or previous pelvic inflammatory disease. Histologic examination of the biopsied endometrium showed no granulomas; however, culture of the endometrium yielded Mycobacterium tuberculosis. When the patient was called back for antituberculosis chemotherapy, we found that she had become pregnant within one month of the endometrial biopsy. Antituberculosis chemotherapy was commenced at 14 weeks' gestation with rifampicin, isoniazid, pyrazinamide and pyridoxine. The pregnancy remained uneventful, and the patient delivered a normal female infant, 3,380 g at term. Pathologic examination of the placenta was performed, but there were no granulomas or features of chronic inflammation. CONCLUSION: Despite the successful fertility outcome in our patient, we do not think that this case was a challenge to previous concepts of endometrial tuberculosis. In vitro fertilization and embryo transfer are usually the most suitable options for these patients.

Adult↗
PubMed1999

Clinics in diagnostic imaging (41). Viable fractured kidney.

A 21-year-old man sustained blunt injury leading to major left renal laceration (Organ Injury Scale Grade IV). The upper and lower poles of the left kidney remained perfused and excreted contrast satisfactorily. Extensive contrast extravasation and urinoma formation were noted. The patient was managed nonoperatively and blood transfusion was given. His left kidney function was preserved and he remains well at 55-month follow-up. The role of imaging in the evaluation of renal injuries and the management of patients with blunt renal trauma are discussed.

Adult↗
PubMed1999

Clinics in diagnostic imaging (44). Testicular tumour with retroperitoneal lymphadenopathy and inferior vena cava thrombosis.

A 20-year-old Indian man presented with a two week history of non-specific abdominal pain. Abdominal ultrasonograpy incidentally detected a thrombus in the inferior vena cava (IVC). Computed tomography revealed the presence of extensive para-aortic lymph node disease as well as a filling defect in the IVC. Scrotal ultrasonography located a heterogeneous intra-testicular tumour in an otherwise palpably-normal testis. The extent of the IVC thrombus was evaluated by the use of magnetic resonance imaging. Inguinal orchidectomy was performed and histology revealed a non-seminomatous germ cell tumour. Combination chemotherapy led to complete resolution of lymph node disease and IVC thrombus. The patient remained well 9 months after diagnosis. The causes of IVC obstruction, role of imaging in investigating IVC obstruction and the management of tumour involvement of the IVC are discussed.

Adult↗