Browsing by Author "Mahendra, G."

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Acute on chronic osteomyelitis due to coliforms in a Sri Lankan child with homozygous sickle cell disease
(Sri Lanka College of Paediatricians, 2021) Hoole, T.J.; Arunath, V.; de Silva, M.H.A.D.; Muthukumarana, O.G.W.; Kumarasiri, I.M.; Rathnasiri, G.B.A.M.R.; Mahendra, G.; Premawardhena, A.; Mettananda, S.
No Abstract Available
Ectopic pancreatic rest in the stomach
(College of Surgeons of Sri Lanka, 2020) Pinto, D.; Kumarage, S.; Mahendra, G.
No abstract available
Immunophenotypic distinction between pigmented villonodular synovitis and haemosiderotic synovitis
(BMJ Publishing Group, 2010) Mahendra, G.; Kliskey, K.; Athanasou, N.A.
AIM: Haemosiderotic synovitis (HS) is caused by excessive bleeding into a joint. It occurs secondary to a variety of conditions and needs to be distinguished from pigmented villonodular synovitis (PVNS) for the purposes of treatment. The histopathological distinction between these conditions, particularly in biopsy specimens, can be problematic. METHODS: Immunophenotypic findings in 20 cases of PVNS and 20 cases of HS were analysed using monoclonal antibodies against proliferation (Ki-67), apoptosis (bcl2), macrophage (CD14, CD68, HLA-DR) and osteoclast (CD51) antigens. RESULTS: Macrophages in PVNS and HS expressed CD14 and HLA-DR. The giant cells in PVNS, but not those in HS, expressed CD51 and were negative for CD14 and HLA-DR, indicating that these cells had an osteoclast phenotype. Considerably more CD51-expressing mononuclear cells were noted in PVNS compared with HS. The Ki-67 proliferation index was higher in PVNS than in HS. CONCLUSIONS: The findings indicate that there are immunophenotypic differences in giant cells between PVNS and HS, and that expression of CD51 and a high Ki-67 index effectively distinguishes between these two conditions
Incidental thyroid cancer in the pyramidal lobe and implications for thyroidectomy
(The Sri Lanka Medical Associtation, 2022) Pinto, D.; Mahendra, G.; Fernando, R.
The embryological remnants (ERs) must be removed to achieve a safe and complete ‘total’ thyroidectomy. Residual ERs, after thyroidectomy, may cause recurrence of the initial pathology. This poses management dilemmas, including a difficult reoperation. Active search and removal of the ERs intraoperatively is essential. Primary overt malignancy is rare in ERs. Literature reports several cohort studies of same. The incidence of a micropapillary carcinoma in an ER has not been reported and this brief report describes two patients with Incidental micropapillary carcinoma in the pyramidal lobe, reiterating the need to make removal of ERs the accepted norm in total thyroidectomies.
Intratumoural lymphatics in benign and malignant soft tissue tumours
(Springer International, 2008) Mahendra, G.; Kliskey, K.; Williams, K.; Hollowood, K.; Jackson, D.; Athanasou, N.A.
Soft tissue sarcomas do not generally metastasise via lymphatics, and the presence or absence of lymphatic vessels within sarcomas and benignsoft tissue tumours is not known. In this study, we determined whether lymphatic vessels were present in a wide range of benign and malignant softtissue lesions by examining intratumoural expression of the lymphatic endothelial cell markers, Lyve-1 and podoplanin. Intratumoural Lyve-1+/podoplanin+ lymphatics were not identified in sarcomas apart from all cases of epithelioid sarcoma (a tumour which is known to metastasise to lymph nodes) and a few cases of leiomyosarcoma, rhabdomyosarcoma and synovial sarcoma. Intratumoural lymphatics were also absent in mostbenign soft tissue tumours. Reparative and inflammatory soft tissue lesions contained lymphatics, as did all (pseudosarcomatous) proliferative myofibroblastic lesions including nodular, proliferative and ischaemic fasciitis, elastofibroma, nuchal fibroma and deep fibromatosis. Our results show that most soft tissue sarcomas do not contain intratumoural lymphatics, a finding which is consistent with the infrequent finding of sarcoma metastasis to lymph nodes. In contrast to fibrosarcoma and a number of other malignant spindle cell tumours, proliferative fibroblastic/myofibroblastic lesions of soft tissue contain intralesional lymphatic vessels.
Necrotic and inflammatory changes in metal-on-metal resurfacing hip arthroplasties
(Informa Healthcare, 2009) Mahendra, G.; Pandit, H.; Kliskey, K.; Murray, D.; Gill, H.S.; Athanasou, N.A.
BACKGROUND: Necrosis and inflammation in peri-implant soft tissues have been described in failed second-generation metal-on-metal (MoM) resurfacing hip arthroplasties and in the pseudotumors associated with these implants. The precise frequency and significance of these tissue changes is unknown. METHOD: We analyzed morphological and immunophenotypic changes in the periprosthetic soft tissues and femoral heads of 52 revised MoM arthroplasties (fracture in 21, pseudotumor in 13, component loosening in 9, and other causes in 9 cases).RESULTS: Substantial necrosis was observed in the periprosthetic connective tissue in 28 of the cases, including all pseudotumors, and 5 cases of component loosening. A heavy, diffuse inflammatory cell infiltrate composed mainly of HLA-DR+/CD14+/CD68+ macrophages and CD3+ T cells was seen in 45 of the cases. Perivascular lymphoid aggregates composed of CD3+ cells and CD20+ B cells were noted in 27 of the cases, but they were not seen in all cases of component loosening or pseudotumors. Plasma cells were noted in 30 cases. Macrophage granulomas were noted in 6 cases of component loosening. In the bone marrow of the femoral head, a macrophage and T cell response was seen in 31 of the cases; lymphoid aggregates were noted in 19 of the cases and discrete granulomas in 1 case. INTERPRETATION: Our findings indicate that there is a spectrum of necrotic and inflammatory changes in response to the deposition of cobalt-chrome (Co-Cr) wear particles in periprosthetic tissues. Areas of extensive coagulative necrosis and a macrophage and T lymphocyte response occur in implant failure and pseudotumors, in which there is also granuloma formation. The pathogenesis of these changes is uncertain but it may involve both a cytotoxic response and a delayed hypersensitivity (type IV) response to Co-Cr particles.
Possible progression of an atypical leiomyoma to a leiomyosarcoma: a case report
(Menopause Society of Sri Lanka, 2021) Ekanayake, C.D.; Herath, R.; Fernando, S.; Mahendra, G.; Balawardene, J.; de Silva, A.
The spectrum of uterine smooth muscle cell tumours (SMT) ranges from leiomyomas to leiomyosarcomas (LMS). Atypical leiomyomas (AL) are a uterine SMT of a contentious nature due to its indeterminate malignant potential. Although the risk of recurrence is low there is limited experience on management. On the other hand, it is generally believed that the uterine LMS arises de novo, rather than from a precursor lesion.
A Retrospective Study on Perinatal Post Mortems
(Faculty of Graduate Studies, University of Kelaniya, Sri Lanka, 2016) Liyanage, S.K.; Mahendra, G.; Ratnayake, S.; Hewavisenthi, J.
A detailed post mortem examination is the key to the recognition of pathologies related to perinatal deaths. Post mortem findings assist the clinical team in confirming their clinical and radiological findings and the family for future pregnancy planning. However, this facility is still underutilized in Sri Lanka. Furthermore, examination of the placentas is an important aspect in recognizing the cause of perinatal death. The department of pathology, faculty of medicine, University of Kelaniya provides the perinatal pathology service to the Obstetrics and Gynaecology unit and the neonatal unit of the Teaching Hospital Ragama. This study was carried out in view of improving and expanding the perinatal pathology service provided by the department. Objectives were (1). To identify the number of perinatal post mortems (PPMs) reported over a period of six years. (2). To identify the number of PPMs that showed multiple congenital anomalies (3). To identify the number of PPMs accompanied by a placenta and the number of placentas with identifiable pathology. This was a retrospective study on already reported PPMs in the Department of Pathology, Faculty of medicine, University of Kelaniya, From January 2011 to August 2016. The PPM databases maintained in the department were used to extract data. A total of 118 PPMs were reported (2011-17, 2012-16, 2013- 17, 2014-21, 2015-31, 2016-16). 65 % (75/118) were premature deliveries. 56% (67/118) were performed following intrauterine deaths. 14 % (16/118) of PPMs showed multiple congenital anomalies. Placentas ware submitted for examination in 31 PPMs (31/118) and clinically significant placental pathologies were noted in 7/31 placentas (23%). 76/118 (64%) showed no gross abnormality in the fetus/baby and placenta was not available for examination in 72% (55/76). Major congenital anomalies were detected in 14% of PPMs. In majority of the PPMs, the placenta was not available for examination, therefore cannot exclude the possibility of placental pathology which might have led to the death.
Smooth muscle actin expression in primary bone tumours
(Springer International, 2012) Hemingway, F.; Kashima, T.G.; Mahendra, G.; Dhongre, A.; Hogendoorn, P.C.W.; Mertens, F.; Athanasou, N.A.
ABSTRACT: Alpha isoform of smooth muscle actin (SMA) expression has been reported in giant cell tumour of bone (GCTB) and other benign and malignant bone tumours, but the pattern of SMA expression and the precise nature of SMA-expressing cells in these lesions is uncertain. We determined by immunohistochemistry the expression of SMA and other muscle and vascular markers in normal bone, GCTB and a wide range of primary benign and malignant bone tumours. Cultured stromal cells of GCTB, chondroblastoma (CB), and aneurysmal bone cyst (ABC) were also analysed for SMA expression. SMA was only noted in blood vessels in normal bone. SMA was expressed by mononuclear stromal cells (MSC) cultured from GCTB, ABC and CB. SMA was strongly and diffusely expressed by MSC in non-ossifying fibroma, fibrous dysplasia, and "brown tumour" of hyperparathyroidism. SMA expression was also noted in GCTB, ABC, CB, chondromyxoid fibroma, malignant fibrous histiocytoma of bone and osteosarcoma. Little or no SMA was noted in Langerhans cell histiocytosis, simple bone cyst, Ewing's sarcoma, osteoblastoma, osteoid osteoma, enchondroma, osteochondroma, chondrosarcoma, myeloma, lymphoma, chordoma and adamantinoma. Our findings show that there is differential SMA expression in primary bone tumours and that identifying the presence or absence of SMA is useful in the differential diagnosis of these lesions. The nature of SMA-expressing cells in bone tumours is uncertain but they are negative for desmin and caldesmon and could represent either myofibroblasts or perivascular cells, such as pericytes.
Total pancreatectomy for cholangiocarcinoma of the distal common bile duct associated with lipomatous pseudohypertrophy of pancreas
(EDORIUM Journals, 2015) Jayatunge, S.P.; Mahendra, G.; Siyabalapitiya, S.; Siriwardana, R.C.; Liyanage, C.
Introduction: Fatty replacement of the exocrine pancreas also known as lipomatosis, adipose atrophy or lipomatous pseudohypertrophy is a well recognize benign condition. This fatty infiltration can occur either focally or involving the whole pancreas. Case Report: We report a rare case of lipomatous pseudohypertrophy of the pancreas associated with cholangiocarcinoma of the distal common bile duct (CBD). A 51-yearold female presented to our unit with a history of obstructive jaundice. Radiological imaging suggested a cholangiocarcinoma of the distal CBD with pancreatic lipomatosis, without any clinical evidence of exocrine or endocrine dysfunction. She underwent a radical bile duct excision and a total pancreatectomy. Histology revealed lipomatosis of the pancreatic body and tail with sparse pancreatic tissue adjacent to the tumor. After an uneventful recovery, she was started on lifelong insulin and pancreatic enzyme supplements. Even though pathogenesis of pancreatic lipomatosis remains controversial, it is most likely due to obstruction of the pancreatic duct in this presentation. Conclusion: It is import to undertake total pancreatectomy for this dual presentation with specialized endocrinological support in the stormy postoperative period.
Trends in early onset colorectal cancer (EOCRC) in a South Asian cohort: data from a specialized tertiary care center in western Sri Lanka
(The College of Surgeons of Sri Lanka, 2022) Chandrasinghe, P.; Godahewa, S.; Mahendra, G.; Hewavissenthi, J.; Kumarage, S.
Introduction Early onset colorectal cancer [EOCRC] has significantly increased during the past decade globally. It is defined as cancers diagnosed in those aged 50 years or less. Most research on EORC are from western populations where the tumour biology and risk factors may differ from other regions. Evidence on EOCRC from the South Asian region is particularly scarce. This study presents the basic trends in presentation and overall survival [OS] pattern of EOCRC using data from a single specialized tertiary care institution over two decades. Methods A total of 723 patients treated at the University surgical unit of the North Colombo teaching hospital from 1995 to 2020 were included in the analysis. Overall survival of the EOCRC was compared with that of the older population using Kaplan- Meier survival curves. Survival patterns over two time periods [pre-2010 vs post-2010] were also compared between the two populations. The stage at presentation, family history of colorectal or related cancers, tumour site, and tumour stage were also compared. Results The proportion of EOCRC in this cohort has not shown a significant increase over the past two decades [2001-2010: 24% vs 2011-2020: 21%]. The advanced tumour stage at presentation and the presence of significant family history are also comparable. EOCRC cohort demonstrates a better OS for the entire study period [Median survival: < 50 years – not reached; >50 years – 91 months; 95%CI – 72-132; P<0.001]. However, this survival advantage is only observed during the pre-2010 period [Median survival: < 50 years – 160 months; 95%CI – 120 – not reached; >50 years – 84 months; 95%CI – 62-132; P=0.01] and becomes comparable in the 2010-2020 period [P=0.16]. OS of the EORC has not also improved over the two decades from 2001 to 2020 [P=0.51]. Conclusion There is no significant increase in the EOCRC rates in this population over time although the rate has remained high throughout. The OS of the EOCRC population is better compared to the older population. A significantly better OS is observed during the pre-2010 period in the EOCRC but is not present in the post-2010 period. Advancement in therapy may have improved the survival of the older population during the latter part but not that in the EOCRC due to its inherently aggressive nature. This paper provides preliminary data on EOCRC from Sri Lanka. The South Asian population may have a different disease pattern with younger age at onset compared to the western populations and needs to be further explored.
Umbilical endometriosis-A simple but challenging diagnosis for surgeons
(College of Surgeons of Sri Lanka, 2014) Jayathilake, K.G.H.; Withana, S.; Siriwardana, R.; Mahendra, G.; Liyanage, C.