Joon Joon Khoo

Pediatric Appendicitis in a Developing Country: What are the Clinical Predictors and Outcome of Perforation?

OBJECTIVES This study explored the risk factors and outcomes associated with perforation in children who underwent emergency appendicectomies. METHODS A retrospective cross-sectional study was conducted on children <13 years old who underwent appendicectomies in a Malaysian hospital in 2007. RESULTS One hundred thirty-four children underwent appendicectomies of which 118 were confirmed histologically. Sixty-one (52%) were perforated. Children with perforation had significantly longer duration of symptoms (p < 0.001), higher white cell count and absolute neutrophil counts (p = 0.013), with longer intra-operative period (p < 0.001) and post-operative recovery period (p < 0.001). Of the 52 samples of pus collected intra-operatively, 37 (71.1%) yielded positive cultures that were predominantly Escherichia coli (n = 27). Both the patients who had Staphylococcus aureus cultured from pus collected intra-operatively had significant pyogenic complications (scrotal pyocele and intra-abdominal abscess). CONCLUSION Children whose appendicitis were perforated had longer duration of symptoms, higher white cell counts and absolute neutrophil counts. Those with S.aureus cultured from intra-operative pus appeared to suffer more complications.

Automating measurement of renal interstitial fibrosis: Effect of colour spaces on quantification

The progression of chronic renal diseases is primarily measured by the extent of interstitial fibrosis and glomerulosclerosis in renal biopsies. The traditional method of interstitial fibrosis quantification uses visual evaluation, which presents high inter- and intra-observer variability. In this paper, we investigate automated quantification methods based on various colour spaces in renal biopsy images. The system identifies and extracts structures in the renal biopsy image based on the colour information presented by the image following a set of knowledge-based rules on the different structures in a microscopic renal biopsy image. The quantification results indicate that a hybrid method which incorporates different colour spaces to segment tissue structures achieves higher accuracy compared to thresholding or clustering methods. It reduces the error of single colour space methods by half, achieving a mean error of 6 percentage points.

Third-year medical students’ views on autopsies

Aims This study was to explore the perceptions of medical students regarding autopsies. Methods Questionnaires were distributed to third-year medical students at Monash University Malaysia after a visit to the morgue to observe an autopsy. Results A total of 129 medical students participated in this study. The majority of students (88.4%) found the autopsy session useful and worthwhile. 89.9% of students said they were able to understand the importance of autopsy and its indications. They also felt they were better equipped in future to communicate with relatives of deceased patients on whom autopsies were performed. Only a minority of the students (18.9%) found autopsy distasteful and an unpleasant experience while a handful (less than 10%) felt that autopsy was disrespectful to the dead. One-third of the students would agree to an autopsy on themselves or their immediate relatives but more than three-quarters of them would request clinical autopsies on their patients if indicated. 77.5% of the students recommended making autopsy session compulsory during undergraduate medical training. Various interesting comments and experiences from the students were also discussed. Conclusion Attending autopsy is useful in various ways and should be made compulsory in undergraduate medical training.

Automatic renal interstitial fibrosis quantification system

Interstitial fibrosis in renal biopsies has shown a good correlation to the presence of chronic kidney disease, and it is therefore quantified by pathologists in the diagnosis of the disease. In the previous work, the developed automatic quantification system for the interstitial fibrosis was presented. It was based on the segmentation of tubular structures. This paper advances the development of the system by expanding the set of identifiable structures to include glomerulus, arteries, and urinary casts. In particular, it investigates two methods of the glomerular detection, namely the Bowmans space search and rLADTree classification. The quantification results of the final system incorporating segmentation of all commonly seen structures have shown a quantification matching that produced by the ground truth to within 8.8%, while the glomerulus structure detection by rLADTree classification method outperformed its alternative due to its higher robustness in tolerating the variance in the glomerulus appearance.

Histopathological analysis of infectious and non-infectious granulomatous lymphadenitis

Introduction: Granulomatous lymphadenitis encompasses infectious and non-infectious aetiologies. A histopathological study is a key step in identifying the underlying pathology to offer appropriate management. Aim: To evaluate the incidence, clinical and histopathological diagnoses of patients with granulomatous lymphadenitis. Methods: A retrospective study was conducted to review all patients with histopathological diagnosis of granulomatous lymphadenitis for a 3-year period. The demographic data, clinical diagnoses and histopathological findings were collected. Results and Discussion: There were 148 patients with granulomatous lymphadenitis with a mean age of 33.2 ± 14.3 years. Ziehl-Neelsen staining for acid fast bacilli (AFB) and fungal staining were done for all cases. There were 106 cases of tuberculous lymphadenitis: 43 cases of which were AFB-positive (40.6%). Twenty-three cases of AFB-positive tuberculous lymphadenitis (or 21.9%) were not suspected clinically of tuberculosis. Immigrants made up a disproportionately high percentage (17.9%) of the 106 cases of tuberculous lymphadenitis. The remaining 42 cases of granulomatous lymphadenitis showed no infectious aetiology except for a case of Cryptococcus lymphadenitis. Conclusion: The majority (71.6%) of granulomatous lymphadenitis was tuberculous lymphadenitis. Sensitivity for AFB staining was 40.6%. Tuberculous lymphadenitis was fairly common among immigrants and clinicians treating them should have a higher index of suspicion.

Clinicopathological review of 565 cases of lymph node biopsies

Aim: To study the spectrum of diseases in lymphadenopathy and identify features that help predict malignant lymphadenopathy. Methods: A 3-year retrospective study was conducted to analyse the spectrum of diagnoses with respect to age, gender, site and size of the lymph nodes. Results and Discussion: There were 565 patients with isolated excised lymph nodes for histopathological examination. Their age ranged from 1.0 to 80.0 years old. The most frequent diagnoses were reactive lymphoid hyperplasia (33.3%), granulomatous inflammation (26.2%), lymphomas (23.5%), metastatic carcinomas (14.0%) and lymphadenitis of other causes. When a node was malignant, it was twice as likely to be a lymphoma as a metastatic carcinoma. A significantly higher proportion of cases were benign in patients who were younger than 40 years old and conversely a significantly higher proportion of cases were malignant in the older age group (p < 0001, OR = 6.209). The best discriminating size of nodes between benign from malignant conditions was 32 mm. Similarly, the size best to differentiate between diagnoses of known and unknown aetiology was 32 mm. However, the site of the node was not correlated to the pathology. Conclusion: The most frequent lymphadenopathy was reactive lymphoid hyperplasia. Age and size of the node were useful for predicting malignant lymphadenopathy.

A multi-faceted approach in pathology teaching to year three medical undergraduates

Introduction Pathology is the basis of medicine and forms the building blocks of medicine. It is the foundation on which students build their understanding of clinical conditions. Thus, it is very important that students’ foundation of learning pathology is strong and the students are given a good start to understand medicine and become competent doctors. Aims A multi-faceted approach in pathology teaching to year three medical students was initiated to achieve the following aims: to influence students’ approach to learning, to give students a realtime experience, to teach students to learn to gather information at their own pace and way, and to maintain a sustained interest in them such that we impart in students a culture of self-directed learning. Methods The methods of teaching used include blackboard online clinic-pathological case (CPC) learning, interactive CPC tutorials, real-time experience in laboratory visits, attending full autopsies, and pathological quizzes with incentives. Evaluation forms were given to students for the teaching they received. Results The students rated highly the CPCs tutorials with a mean rate of 5.27 over a score of 1 to 6. Students were highly appreciative of the pathology quizzes and gave a mean score of 5.0. The students also felt they had received great value from participating in the laboratory visits and morgue visits. Similarly, the students felt that a visit to the morgue to attend autopsies should be made compulsory in the medical curriculum. Conclusion A multi-faceted approach in pathology teaching to undergraduates is recommended over the routine class room teaching.

Difficulty in diagnosis of a very rare tumour: hepatosplenic γδ T-Cell lymphoma that presented as an acute intestinal obstruction

Introduction Hepatosplenic γδ T-cell lymphoma is a rare type of aggressive lymphoma predominantly affecting the liver and spleen. Case report We present a 19-year-old man admitted with fever, pancytopenia and acute intestinal obstruction. During emergency laparotomy he was found to have hepatosplenomegaly with lymphadenopathy along the mesentery. The spleen was enlarged and had compressed on the large bowel. The red pulp of the spleen was replaced by atypical lymphoid cells in a sinusoidal and perisinusoidal distribution. They were reactive to CD3, CD4, CD56, and TIA but negative to CD20, CD79a, CD5, CD57 and BF1. PCR analysis for clonal T-cell receptor gamma chain gene rearrangement studies was attempted from the paraffin blocks of the spleen. It was diagnosed as hepatosplenic γδ T-cell lymphoma. However, the patient defaulted and was readmitted 8 months later with pancytopenia, fever and jaundice. He developed leukaemic involvement of the bone marrow and succumbed to the illness 2 weeks later. Discussion The clinical presentation, morphology and its various immunohistochemical stains characteristic of hepatosplenic γδ T-cell lymphoma are discussed together with the problems and difficulty encountered in confirming the diagnosis. Hepatosplenic γδ T-cell lymphoma is aggressive and median survival is less than a year following diagnosis, despite treatment.