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Sheung-Fat Ko

Publications and source records attributed to Sheung-Fat Ko.

At least 55 records · Page 3Linked to original sources
PubMed2004

Clinical usefulness of 18F-FDG PET in nasopharyngeal carcinoma patients with questionable MRI findings for recurrence.

UNLABELLED: It has been reported that 18F-FDG PET is highly sensitive for the detection of recurrent head-and-neck cancer. The objective of our prospective study was to validate the ability of this technique to detect the presence of tumors in primary, nodal, and distant sites as well as to assess its overall clinical usefulness in patients with questionable MRI findings for residual or recurrent nasopharyngeal carcinoma (NPC). METHODS: From January 2002 to October 2003, a group of 37 NPC patients whose postradiation follow-up MRI examination showed questionable residual or recurrent disease was assessed with 18F-FDG PET. 18F-FDG PET was interpreted visually. Disease at primary, nodal, and distant sites was assessed. The final diagnosis was confirmed histopathologically or with clinical and imaging follow-up of at least 6 mo. RESULTS: Our results showed that the sensitivity and specificity of 18F-FDG PET for the detection of recurrent NPC were 91.6% and 76.0%, respectively, at the primary site; 90.0% and 88.9%, respectively, at nodal sites; and 100% and 90.6%, respectively, at distant sites. The overall sensitivity and specificity were 89.5% and 55.6%, respectively. Among the 37 patients, 18F-FDG PET added significant information to the MRI findings in 18, including offering true-negative findings in 10, revealing unexpected small metastatic adenopathy in 3, and disclosing distant metastatic foci in 5. CONCLUSION: 18F-FDG PET is highly sensitive and moderately specific for the detection of recurrent NPC in patients with questionable MRI findings. Overall, 18F-FDG PET appears to add significant information to MRI findings in about half of the NPC patients whose MRI examination shows questionable tumor recurrence.

Adolescent↗
PubMed2004

Anemia as the sole presenting symptom of idiopathic pulmonary hemosiderosis: report of two cases.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disease in children and has an unknown etiology. It is characterized by the triad of hemoptysis, pulmonary infiltrates on chest radiograph (CXR) and iron deficiency anemia. We report two young children, aged 3 and 4 years, were admitted due to pale-looking appearance but without hemoptysis or other respiratory symptoms. Pallor was the sole presenting feature in these 2 children with IPH and which was unusual. CXR obtained on admission led to the suspicion of pulmonary hemorrhage. The diagnosis of IPH was confirmed based on the presence of many hemosiderin-laden macrophages in bronchoalveolar lavage fluid obtained by flexible bronchoscopy. Steroid was initiated after the diagnosis of IPH was established; the both of them have been well and received regular follow-up in our outpatient department. IPH may not be diagnosed because of difficulty in diagnosis. Anemia may be the only presenting feature of IPH, which was due to occult pulmonary hemorrhage. Initial treatment with corticosteroids has been successful in our patients for a period of 6 and 8 months of follow up respectively.

Adrenal Cortex Hormones↗
PubMed2003

Idiopathic calcific constrictive pericarditis causing pulmonary stenosis associated with a ventricular septal defect mimicking tetralogy of Fallot.

We describe an unusual case of pulmonary stenosis caused by calcific constrictive pericarditis associated with a congenital ventricular septal defect in a 16-year-old boy who had a 2-week history of progressive dyspnea, cyanosis, fatigue, and bilateral leg edema. Echocardiographic findings led to an initial diagnosis of tetralogy of Fallot; however, findings on chest radiography and CT were suggestive of calcific constrictive pericarditis with pulmonary stenosis, which was then confirmed on cardiac catheterization. Total pericardiectomy and repair of the ventricular septal defect resulted in a satisfactory outcome. Follow-up examinations at 6 and 20 months showed that the patient was asymptomatic and considered to have class I New York Heart Association functional status. To our knowledge, this is the first reported case of calcific constrictive pericarditis with pulmonary stenosis associated with a ventricular septal defect.

Adolescent↗
PubMed2003

Castleman disease of the pleura: experience with eight surgically proven cases.

BACKGROUND: Castleman disease of the pleura is unusual, and we present our experience with eight surgically proven cases. METHODS: Between 1980 and 2002, 8 patients (7 women and 1 man; age range, 20 to 53 years; mean, 26.5 years) with surgically proven, pleural Castleman disease (six hyaline vascular type, one plasma cell type, and one mixed type) were encountered. Their clinical, imaging, and surgical findings were reviewed. RESULTS: Five patients were asymptomatic, 1 had dyspnea, 1 had cough, and 1 experienced chest discomfort. Chest radiography showed a well-circumscribed interlobar, cardiophrenic, or paraaortic mass in 6 patients, a massive effusion in 1, and a focal diaphragmatic bulge in 1. Six tumors showed varying degrees of contrast enhancement (10 to 95 HU; mean, 46 HU) on computed tomography. Three cases appeared as well-defined, heterogeneously hyperintense pleural masses on magnetic resonance imaging. The masses varied in size from 3 to 10 cm (mean, 5.2 cm). Five masses greater than 5 cm had prominent pleural arterial blood supply and severe adhesions requiring thoracotomy and resection of nearby structures for radical tumor excision. Blood loss from patients varied between 100 and 850 mL (mean, 620 mL). No tumor recurrence was noted during follow-up (range, 1 to 16 years; mean, 6.5 years). CONCLUSIONS: Pleural Castleman disease predominately affects young women and manifests as a well-circumscribed mass with a varying degree of contrast enhancement on computed tomography and heterogeneity on magnetic resonance imaging. Tumors greater than 5 cm have profuse pleural blood supplies and severe adhesion necessitating open thoracotomy and resection of neighboring structures. Radical resection can produce a satisfactory outcome.

Adult↗
PubMed2003

Perirenal tailgut cyst (cystic hamartoma).

Tailgut cysts are rare congenital multicystic lesions preferentially occurring in the retrorectal space. They are assumed to arise from the remnant of embryonic tailgut and occasionally exhibit malignant transformation. The authors herein describe the clinical, radiologic, and pathologic features of an unusual perirenal tailgut cyst with an emphasis on its histogenesis and distinction from other intraabdominal cystic lesions.

Abdominal Pain↗
PubMed2003

Echocardiographic guidance for transcatheter coil occlusion of patent ductus arteriosus in the catheterization laboratory.

The objective of this study was to investigate the feasibility of transthoracic echocardiography as a guide to monitor the completeness of patent ductus arteriosus (PDA) occlusion immediately after coil implantation. In all, 52 patients who underwent Gianturco coil implantation for PDA occlusion were evaluated by transthoracic echocardiography within 15 minutes after the first coil implantation in the catheterization laboratory. According to Doppler echocardiographic findings, these patients were classified into 3 groups: group 1, complete occlusion without residual shunt; group 2, a residual PDA diameter < 1 mm and no continuous waveforms detected; and group 3, a residual PDA diameter >or= 1 mm or continuous waveforms. There were 34 patients in group 1, 10 patients in group 2, and 8 patients in group 3. In a 12-month follow-up the complete occlusion rate was 100%, 90%, and 87.5% in groups 1, 2, and 3, respectively. We conclude that immediate Doppler echocardiography is useful in assessing the status of residual PDA just after coil implantation. Residual shunt < 1 mm and lack of continuous waveform on Doppler scan indicate sufficient ductal closure of PDA.

Adolescent↗
PubMed2003

Successful management of acute renal artery thromboembolism by intra-arterial thrombolytic therapy with recombinant tissue plasminogen activator.

Acute renal artery thromboembolism (ARAT), a rare event in native kidneys, potentially result in severe renal injury if it is not appropriately managed. The optimal therapy still remains controversial today even though various methods of managements for ARTA were applied in these decades including surgical intervention and medical approach such as thrombolytic therapy. Recombinant tissue plasminogen activator (rt-PA) reveals a better bioavailability and lower incidence of adverse effects and it has been widely used to treat a number of clinical conditions but only very few cases have been reported where rt-PA was used to treat ARAT. We described a case of ARAT, which was successfully treated by the administration of rt-PA via intra-arterial infusion within a period of 60 min without residual renal impairment. It may be a useful choice for ARAT and renal infarction sufferers.

Acute Disease↗
PubMed2003

Obstructive jaundice as the presenting manifestation of Burkitt's lymphoma in a 4-year-old boy.

Obstructive jaundice often occurs as a late manifestation of non-Hodgkin's lymphoma (NHL), but has rarely been reported as a presenting manifestation, especially in children. We report a case of a 4-year-old boy with Burkitt's lymphoma (small non-cleaved cell NHL) who presented with obstructive jaundice, resulting from encasement of the common bile duct by the tumor. The patient underwent near-total excision of the tumor and biliary-enteric bypass to relieve the jaundice. Combined chemotherapy was not given because of refusal by his family. Two weeks after the operation, obstructive jaundice reappeared due to a large recurrent tumor compressing the liver hilum. He received chemotherapy and the jaundice disappeared within 6 days. Follow-up computed tomography 1 year later revealed total resolution of the tumor. Three conclusions are suggested by this case. First, although NHL presenting as obstructive jaundice is uncommon in children, it should be included in the differential diagnosis. Second, relief of obstructive jaundice can be effectively accomplished by chemotherapy alone. Third, chemotherapy should be given once NHL is diagnosed.

Burkitt Lymphoma↗
PubMed2003

Predictors of esophageal stricture in children with unintentional ingestion of caustic agents.

BACKGROUND: Prediction of the severity of esophageal injury following ingestion of a caustic substance is a challenging problem for clinicians. It was hoped that risk factors for the early prediction of esophageal stricture in such patients could be identified in this study. METHODS: This study comprises an evaluation of 32 children with esophageal injury due to ingestion of caustic materials. Patients' signs and symptoms as well as laboratory data including leukocyte counts and C-reactive protein level were reviewed. RESULTS: Patients who presented with a greater number of symptoms and signs were inclined to have more severe esophageal injury and stricture. The frequency of symptoms and signs in patients with serious esophageal injury was higher than that in patients with low-grade injury. Patients with severe injury were more significantly associated with the occurrence of stricture. The characteristic of caustic ingestion was associated with esophageal stricture, but not esophageal injury. There was no statistically significant difference in leukocyte counts relative to severity of esophageal injury. The mean of leukocyte counts of patients with esophageal stricture was close to that of patients without esophageal stricture. There was also no statistically significant difference in C-reactive protein values between the 2 groups of patients. CONCLUSIONS: Leukocyte counts and C-reactive protein are not useful parameters for predicting the severity of esophageal injury and occurrence of stricture following injury to the esophagus by caustic materials. Alkali ingestion more probably leads to esophageal stricture than acid ingestion. After caustic ingestion, the presence of a greater number of symptoms and signs suggests a more-severe injury, which necessitates more-aggressive management.

Adolescent↗
PubMed2003

Urachal inflammatory mass mimicking an intra-abdominal tumor two years after excision of the urachal sinus in a child.

A 2-year-and-2-month-old boy presented with a tender fist-sized mass in the lower abdomen for 3 days. Turbid urine was also a complaint. His urachal sinus and umbilicus had been removed at the age of 2 months. Abdominal ultrasonography and computed tomography revealed a tumor mass beneath the lower abdominal wall. Total excision of the mass was performed. Microscopic examination showed an abscess located next to a small urachal remnant without stitches or foreign body reaction. To our knowledge, an urachal inflammatory mass mimicking an intra-abdominal tumor after excision of the urachal sinus, especially in children, is very rare. The factors causing such an urachal mass are discussed.

Abdominal Neoplasms↗
PubMed2003

Appendicitis complicated by hemoperitoneum.

Differential diagnosis of acute appendicitis in women of childbearing age is a challenge because of the range of gynecologic and obstetric problems with similar manifestations. We report a case of acute appendicitis with the rarely encountered complication of hemoperitoneum in a sexually active 32-year-old woman. The patient presented with right lower quadrant pain and a positive culdocentesis with non-clotting blood. Hemorrhagic corpus luteal cyst was the initial impression. Ruptured appendicitis with abscess formation and complicated hemoperitoneum was diagnosed later with the aid of abdominal computed tomographic scan, and was confirmed during operation. Hemoperitoneum may be a complication of appendicitis with abscess formation; a detailed medical history and physical examination are helpful in making the diagnosis.

Adult↗
PubMed2002

Small bowel intussusception in symptomatic pediatric patients: experiences with 19 surgically proven cases.

Nineteen cases of surgically proven symptomatic pediatric small bowel intussusceptions (SBI) were retrospectively reviewed. Clinical presentations included vomiting (89.5%), abdominal pain and/or irritable crying (89.5%), fever (52.6%), bloody stools (26.3%), palpable abdominal masses (15.8%), hematemesis (10.5%), jaundice (5.3%), and seizures (5.3%). The duration between symptom onset and hospitalization ranged between 20 and 336 hours (average 75.8 hours). Two patients with suspected appendicitis and small bowel obstruction were operated on promptly. Sonograms revealed target lesions (average diameter 2.9 cm) suggestive of intussusception in 13 out of 17 patients, with 10 lesions located in the paraumbilical or left abdominal regions. Barium enemas in 12 of these 13 patients demonstrated no colonic lesions. Diagnosis and surgery were delayed in 16 patients (average delay = 32 hours). The remaining 1 patient with positive sonographic findings underwent early surgery after computed tomographic (CT) confirmation of SBI. Surgery revealed ileoileal intussusceptions in 11 patients, jejunojejunal in 4, jejunoileal in 3, and duodenojejunal in 1. Eight patients had lead points. Bowel complications (ischemia, necrosis, or perforation) occurred in 8 patients. The duration between symptom onset and surgery in patients with bowel complications was significantly longer than for patients without complications (p = 0.0026). In conclusion, delayed diagnosis and surgical treatment in symptomatic pediatric patients with SBI were common, leading to a high rate (42%) of bowel complications. Sonographic demonstration of a 2-3 cm target lesion, especially if paraumbilical or left abdominal, is suggestive of SBI and may obviate the need for a barium enema; however, CT is helpful for confirming SBI. In symptomatic SBI, once diagnosed, early surgical referral is strongly recommended.

Adolescent↗
PubMed2002

Primary mesenchymal chondrosarcoma of the lung.

Mesenchymal chondrosarcoma has been well documented in the somatic soft tissue and bone. It is a rare subtype of chondrosarcoma characterized by the presence of islands of chondroid or by less osteoid tissue enmeshed within dense sheets of primitive small blue mesenchymal cells with hemangiopericytoma-like vessels, or by both. The vast majority of previously published pulmonary mesenchymal chondrosarcoma was metastatic. To the best of our knowledge, only one case of primary pulmonary mesenchymal chondrosarcoma has been described in the literature. Herein, we report the second case of primary mesenchymal chondrosarcoma of the lung and emphasize that biopsy may yield only nonspecific small blue cells, whereas a detailed evaluation of the resected specimen allows definite diagnosis of this rare lung tumor.

Adult↗
PubMed2002

Solitary fibrous tumor of the abdominal wall: a report of two cases immunohistochemical, flow cytometric, and ultrastructural studies and literature review.

Solitary fibrous tumors have been described at many extrapleural sites in recent years. However, solitary fibrous tumors arising from somatic soft tissue occur only rarely and can pose problems in the differential diagnosis from other benign or malignant soft tissue tumors. The majority of solitary fibrous tumors occurring in the somatic soft tissue have been found in the extremities and limb girdles, and the head and neck regions. There have been only eight published cases located in the abdominal wall. We herein report two female patients who developed solitary fibrous tumors of the abdominal wall that were not in association with the underlying peritoneum. Histologically, both tumors were characterized by a variety of architectural patterns, alternating hypercellular and hypocellular areas, proliferation of plump spindle cells, thick keloid-like and/or amianthoid collagen bundles, and ectatic staghorn-like vessels. Both tumors showed a diffuse strong reaction for CD34 and vimentin as well as focal positivity for bcl-2 and smooth muscle actin. A striking predominance in females was found in a literature review of solitary fibrous tumors of the abdominal wall, contrasting with other somatic soft tissue sites which show an equal gender distribution. Interestingly, expression of estrogen but not progesterone receptor was observed in both tumors. Ultrastructurally, the tumor cells displayed features of fibroblasts with dilated branching rough endoplasmic reticulum (RER) and Golgi apparatus. Both tumors assayed by flow cytometry demonstrated a diploid DNA content with an S-phase fraction of 7.9% and 11.4%, respectively. At follow up, both patients were well without evidence of recurrence or metastasis after surgical excision.

Abdominal Neoplasms↗
PubMed2002

Renal artery stenosis presenting with status epilepticus: a report of one case.

In children, renal artery stenosis is an uncommon but important cause of secondary hypertension. In this report, the authors describe a 5-year-old boy with no history of seizures who experienced status epilepticus. Postictal blood pressure, relative hypotension, was misinterpreted as normal on the day of admission. Two days later, his blood pressure rose gradually and peripheral plasma renin activity showed more than 1,700 micro U/mL. Magnetic resonance angiography suggested renal artery stenosis. After successful percutaneous transluminal angioplasty, the patient was seizure-free and had well-controlled blood pressure. This case describes renal artery stenosis present with status epilepticus, and emphasizes the importance of serial measurements of blood pressure in children.

Child, Preschool↗
PubMed2002

Primary yolk sac tumor of the urachus.

Pure yolk sac tumor is the most common malignant gonadal tumor of infants and toddlers. However, the majority of extragonadal germ cell tumors in the midline are either seminomas (germinomas) or teratomas, and pure yolk sac tumors account for only a small fraction of these lesions. To date, only 1 primary urachal pure yolk sac tumor has been reported in the literature. We describe another case, occurring in a 7-month-old male infant who presented with a rapidly enlarging intra-abdominal tumor with marked engorgement of the superficial venous plexus around the umbilicus. With periodic follow-up for 3 years following surgical extirpation of the tumor and adjuvant chemotherapy, this patient is still alive without evidence of disease. Notably, the glandular elements predominating in the frozen sections resulted in the initial misdiagnosis of the tumor as a urachal adenocarcinoma, although the entirely resected specimen revealed typical histologic patterns and Schiller-Duval bodies. Immunohistochemistry showed that the tumor cells were diffusely reactive to alpha-fetoprotein, alpha(1)-antitrypsin, and cytokeratin. Tumor cells were negative for p53 protein, but revealed overexpression for MDM2 protein. Flow cytometry demonstrated a diploid DNA content with S-phase being as high as 55.36%. This case emphasizes that pure yolk sac tumor can occur primarily in the remnant of the urachus in young children.

Antineoplastic Combined Chemotherapy Protocols↗