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Biomedical subjects

M P Kumarasinghe

Publications and source records attributed to M P Kumarasinghe.

At least 19 recordsLinked to original sources
PubMed2006

Mapping of hereditary mixed polyposis syndrome (HMPS) to chromosome 10q23 by genomewide high-density single nucleotide polymorphism (SNP) scan and identification of BMPR1A loss of function.

BACKGROUND: Hereditary mixed polyposis syndrome (HMPS) is characterised by colonic polyps of mixed histological types that are autosomal dominantly inherited and eventually lead to colorectal cancer (CRC). Study of the molecular basis of HMPS will enhance our knowledge of the genetic basis of the mixed polyposis-carcinoma sequence in both hereditary and sporadic CRC. METHODS/RESULTS: We performed a genomewide linkage search on 15 members of a three-generation HMPS family using the GeneChip Human Mapping 10K Array and identified a 7 cM putative linkage interval on chromosome 10q23. Subsequently, 32 members from two HMPS families were typed with nine microsatellite markers spanning the region and the linkage was confirmed with a maximum multi-point logarithm of the odds (LOD) score of 4.6 (p<0.001). The 10q23.1-10q23.31 haplotypes segregate with the disease in both families. We screened for mutations in four candidate genes within the linkage region and identified an 11 bp deletion in the bone morphogenesis protein receptor 1A (BMPR1A) gene in one family. CONCLUSIONS: Our results indicate that BMPR1A mutation accounts for HMPS. The data suggest that inactivating BMPR1A can initiate colorectal tumourigenesis via the mixed polyposis-carcinoma sequence.

Adenomatous Polyposis Coli↗
PubMed2005

Correlation of histology with anorectal function following stapled hemorrhoidectomy.

INTRODUCTION: The inadvertent removal of smooth muscle during the use of stapled hemorrhoidectomy had raised concerns about its effects on postoperative anorectal function. We correlated the amount of smooth muscle removed with anorectal function in the early postoperative period. METHODS: Patients were assessed preoperatively with an Eypasch quality-of-life questionnaire and underwent anorectal manometry and physiology testing. This was followed by a similar examination at three months postoperatively. Patients were operated on by a single surgeon and the excised anorectal mucosa was sent for histologic examination. The amount of smooth muscle excised was expressed semiquantitatively as a percentage of the total tissue removed. RESULTS: Sixty-eight patients (33 males) were recruited prospectively, with median age of 44 years. Six patients were lost to follow-up. Removal of anal transitional zone did not increase the incidence of incontinence. Both median preoperative and postoperative continence scores were good. Only one patient had incontinence to gas as a result of the operation. Median preoperative and postoperative quality-of-life scores were 114 and 131, respectively, out of a total of 144, the higher postoperative scores showing an improvement. Correlation of quality-of-life scores and mean resting anal pressures with percentage of smooth muscle removed did not show any statistical significance. CONCLUSIONS: Some smooth muscle will invariably be excised in stapled hemorrhoidectomy but the amount of smooth muscle removed did not significantly affect the continence score, quality of life, or mean anal resting pressure after stapled hemorrhoidectomy. It remains a safe and preferred procedure for the treatment of hemorrhoids.

Adult↗
PubMed2004

"Tap sign" in tuberculoid and borderline tuberculoid leprosy.

Deep pain upon percussion of lesions over bone in tuberculoid leprosy, in spite of superficial sensory impairment, has been described as the "Tap Sign" (TS). This study was conducted to identify possible causes for this phenomenon and to determine the sensitivity and specificity of this sign in leprosy patients with lesions overlying bone. In 37/53 patients with lesions over bone, the sensitivity of the TS was 66.7% and the specificity was 100%. The positive predictive value was 100%, and the negative predictive value was 75%. The Tap Sign appears to be a useful clinical sign in diagnosis of tuberculoid and borderline tuberculoid leprosy where a lesion overlies a bone (sensitivity 66.7%). This test could be very useful to increase the clinical diagnostic yield, in the global perspective, in places where leprosy is diagnosed and treated by healthcare workers and primary care physicians without other laboratory facilities. Possible mechanisms responsible for the deep pain are discussed.

Adolescent↗
PubMed2000

Cytohistologic features of invasive micropapillary carcinoma in a young female.

Invasive micropapillary carcinoma (IMPC) is a recently reported variant of breast carcinoma in women. There has been only a single report describing the cytologic features of IMPC in the literature. We report on the cytohistologic features of IMPC with diffuse involvement of two quadrants of the breast and axillary lymph node metastases in a 32-yr-old female. The cytologic appearance of IMPC was characterized by high cellularity, marked cell discohesion, and epithelial cells forming aggregates, morules, and angular and papillary clusters without fibrovascular cores and showing high nuclear/cytoplasmic ratio, irregular nuclear contours, and finely stippled chromatin. Occasional psammoma bodies were noted. Histologic examination showed a pure IMPC composed of clusters, morules, and aggregates of malignant epithelial cells surrounded by distinctly clear spaces separated by thin fibrovascular septa. The tumor involved both inner quadrants and axillary lymph nodes. A primary tumor elsewhere, particularly in the ovaries, was excluded. The patient has been disease-free 38 mo after the initial diagnosis.

Adult↗
PubMed1999

Pitfalls in cytological diagnosis of autoimmune thyroiditis.

The aims of this study are to document pitfalls in cytologic diagnosis of autoimmune thyroiditis (AT) and highlight possible ways to minimize them. One hundred consecutive thyroid aspirates with features diagnostic or suggestive of AT, performed and reported by the first author, were included in the study. Follow-up was traced and cytologic features responsible for indecisiveness were re-assessed in those reported as suggestive of AT. The features were then correlated with the results of serologic and thyroid function tests and clinical features, and an attempt was made to amend the final diagnosis using an integrated approach. Seventy eight were diagnostic and 22 were suggestive of AT. In the latter 22, features responsible for the indecisiveness were: cytologic atypia, in the form of nuclear enlargement, irregularity and grooves and altered chromatin texture, in 14 (64%); nucleoli with suspicion of a coexisting neoplasm in three (13.6%), two of which showed epithelial preponderance, crowding and discohesion; sparse inflammation in four (18%); a predominant lymphoid population without epithelial cells resembling a reactive lymph node in one (4.5%); co-existing toxic features in two (9%); and scanty smears in one (4.5%). Eighteen of the 22 suspected of AT had follow-up. Six had been assessed histologically; three with features suspicious of a neoplasm were diagnosed respectively as a papillary carcinoma (PC), Hurthle cell carcinoma (HCC) and a multinodular goitre (MNG) with degenerate changes. The other three were confirmed as AT; one with cytologic atypia, one with sparse inflammation and the third as cytologically resembling a reactive lymphnode. In ten of the remaining 12, the final diagnosis could be revised following an integrated approach with possible reduction of the indecisiveness. Potential pitfalls are: cytologic atypia occurring in AT; abundance or scarcity of background inflammation; low cell yield; and co-existing toxicity and malignancies. Epithelial preponderance over inflammation, nuclear crowding, severe atypia and cell discohesion should raise the possibility of a neoplasm in spite of other features of AT. Awareness of possible pitfalls and adopting an integrated approach, especially in difficult situations, will minimize pitfalls.

Adenocarcinoma↗
PubMed1999

Tangles in smears of granulomatous lymphadenitis--a clue to the diagnosis.

OBJECTIVE: To assess the significance and nature of tangles in fine needle aspiration biopsy (FNAB) smears of granulomatous lymphadenitis. METHODS: The study group included 45 cases of clinically suspected granulomatous lymphadenitis particularly of tuberculous origin in which a cytologic diagnosis of granulomatous lymphadenitis (GL) was made on FNAB material. Smears of 21 lymph node aspirates without cytologic evidence of granulomatous disease (NGL) were included as a control group. One case with double pathology was excluded. All smears were fixed in 95% alcohol and stained with haematoxylin and eosin. Tangles were defined as a meshwork of haematoxyphilic string-like material occurring in a tangle in an otherwise well preserved smear. A score was given for the distribution (0-3) and density (1-3) of the tangles on the count of 10 high power fields for each aspirate. Statistical analysis was done by the Mann Whitney U test. RESULTS: Tangles were present in 41 of 45 (91%) GL and 7 of 21 (33%) NGL. The differences were statistically significant (p = 0.0008 and 0.0001 for distribution and density respectively). Six of the seven (84%) NGL with tangles were either cytologically diagnostic or suspicious of malignancy with 5 (71%) showing features of non-Hodgkin's lymphoma. The tangles were positive for nuclear stains (Feulgen) and originated in the nuclei of both lymphocytes and epithelioid cells, probably due to easy fragility of altered nuclear material. CONCLUSION: The presence of tangles in smears should raise the possibility of GL in the absence of a malignancy, specifically a lymphoma. This becomes an important diagnostic clue especially in situations where epithelioid histiocytes, the hall mark of GL, are sparse or absent in cytologic material.

Biopsy, Needle↗
PubMed1998

Non-diagnostic smears in aspiration cytology of palpable breast lumps.

The cytologic diagnoses of a wide variety of breast diseases have been described in the literature and cytologic appearances of some of these are not characteristic. Technical problems during aspiration and smear preparation influence the final diagnosis, therefore, even at best hands a non-diagnostic category is to be expected. The objectives of this study were to determine the frequency of non-diagnostic reports and to assess the source of indecisiveness. This study is based on a retrospective analysis of breast aspirates signed out by the first author over a period of 18 months. The smears with non-diagnostic reports were correlated with the available histologic follow-up to identify the problem area. Forty-eight (9.1%) out of the 527 samples were non-diagnostic and within the recorded range of 6.9% to 20%. Of those 48 in the non-diagnostic category, 30 (62.5%) had histological follow-up. There were 11 (36.7%) malignant lesions and 19 (63.3%) benign lesions. In 23 cases (77%) pure interpretative problems and in 3 cases (10%) pure technical problems were responsible for the non-diagnostic reports. In 4 cases (13%) both factors contributed to the non-diagnostic report. Thirteen of the 30 (43%) lesions were cytologically suspected to be malignant. Of these 13.9 (69%) were found to be malignant while only 4 were benign; thus non-diagnostic but suspicious lesions are more likely to be malignant. The commonest cytologic features responsible for problems at interpretation were high cellularity (37%), cell discohesion (30%), large nuclei and nucleoli (30%) and the small size of the cells (40%). Inadequate or low cell yield (86%), inadequate clinical history (14%) and poor staining (14%) contributed to technical problems. The cytologic diagnosis of breast lesions such as fibromatosis, complex sclerosing lesions, papillary lesions, angiosarcoma and low nuclear grade in situ and invasive carcinomas can be difficult and the cytologic criteria for these diagnoses need further evaluation.

Biopsy, Needle↗
PubMed1997

Methanol as an alternative fixative for cytological smears.

Ninety-five percent (95%) ethanol is the standard cytological fixative used in many laboratories. Commercially available ethanol is expensive and not freely available in some institutions. Methanol, a tissue dehydrant, is also known to be a cytological fixative. However its efficacy has not been assessed or documented in the literature. One hundred and eight consecutive fine needle aspiration biopsies (FNAB) of thyroid performed at the Department of Pathology, Faculty of Medicine, Colombo were included in a study to assess the efficacy of methanol as a cytological fixative. Aspirated material was smeared on at least 2 slides, one fixed in ethanol and the other in methanol, and stained with haematoxylin and eosin (H&E). The 2 smears were separately assessed for preservation of colloid and cells (nuclei and cytoplasm), as determined by the staining quality with the H&E stain. A score was given for each smear and the final scores for ethanol and methanol were statistically compared. The evaporation rates for ethanol and methanol were calculated. The total score for preservation of colloid was 294/300 (98%) for methanol and 291/300 (97%) for ethanol (p = 0.4). The total score for preservation of cells (nuclear and cytoplasmic) was 276/279 (98.9%) for methanol and 274/279 (98.2%) for ethanol (p = 0.7). The evaporation rates per 100 ml when the bottles used for fixation were kept closed and open per 24 hours were 1 and 37 for methanol and 0 and 17 for ethanol. Literature search did not show inhalational side effects of methanol in humans under standard laboratory conditions. We conclude that methanol is as effective as ethanol for fixation of smears and cheaper.

Biopsy, Needle↗
PubMed1997

First reports of subcutaneous sparganosis in Sri Lanka.

OBJECTIVE: To report and create awareness of sparganosis, a parasitic zoonosis caused by a larval stage of Spirometra sp. SETTING: Two patients with non-tender subcutaneous lumps. DIAGNOSIS CRITERIA: Morphology of solid cestode larva in excision biopsies. CONCLUSIONS: Although these two instances were innocuous, infection is potentially dangerous as larvae are long lived and could invade vital organs. The most likely source of infection in Sri Lanka is ingestion of the infected first intermediate host, Cyclops, in water.

Adult↗
PubMed1995

Fine needle sampling without aspiration.

Four hundred and ten thyroid nodules, 127 breast lumps and 43 lymph nodes were sampled and analyzed to compare the classical aspiration (ASP) technique with the non aspiration needle jab (NASP) technique. The adequacy of cellularity, significant blood staining and the discomfort felt by the patient were assessed and statistically analyzed. The non aspiration technique was found to be superior to the classical aspiration technique for fine needle sampling of thyroid in all aspects. However, for breast lesions, while the discomfort felt and the staining with blood was less with the non aspiration technique, the overall cellular yield was unsatisfactory. The adequacy of cellular yield was, however, comparable for malignant breast lesions with either technique. For lymph node sampling, both techniques showed equivalent results with regard to the cellularity but, the NASP technique was superior in other aspects. Although the overall patient discomfort and blood staining was significantly less, the adequacy of the cellularity was influenced by the site and the nature of the lesion. Thus it can be concluded that the technique needs to be selected depending on the anatomic site, the clinical situation, the personal experience and the preference of the operator.

Biopsy, Needle↗