MyMedR

Diagnostic challenges in tuberculous otitis media

Tang IP, Prepageran N, Ong CA, Puraviappan P

J Laryngol Otol, 2010 Aug;124(8):913-5.

PMID: 20426886 DOI: 10.1017/S0022215110000265

To demonstrate the different clinical presentations of tuberculous otitis media and the management of selected cases.

Epithelial migration in open mastoidectomy cavities

Ong CA, Prepageran N, Godbole S, Raman R

Asian J Surg, 2007 Jan;30(1):57-9.

PMID: 17337373

To study the rate and pattern of epithelial migration in 18 dry, open mastoidectomy cavities.

Fulltext Bilateral lacrimal sac mucocele with punctal and canalicular atresia

Ong CA, Prepageran N, Sharad G, Luna D

Med J Malaysia, 2005 Dec;60(5):660-2.

PMID: 16515124

Congenital absence of lacrimal puncta may be an isolated finding or associated with other developmental abnormality. Nasolacrirnal ducts can be absent thus predisposing to the formation of a congenital lacrimal mucocele. Punctal and canalicular agenesis is very rare. Four percent of new patients attending the lacrimal clinic at Moorfields Eye Hospital, London, UK. from 1981 to 1990 inclusive were diagnosed to have this condition. We describe a case of bilateral congenital absence of lacrimal puncta with lacrimal mucocele. Combined surgery was carried out by Ophthalmologist and Otolaryngologist with successful results.

Fulltext Parotid duct mucocele

Ong CA, Loganathan A, Prepageran N, Rahmat O, Lingham OR

Med J Malaysia, 2005 Dec;60(5):644-6.

PMID: 16515118

Parotid swelling is a common presentation in ENT clinic. Most of the cases involve pathology of the gland. There are not many reported cases about parotid duct pathology. We describe a case of a large parotid duct mucocele with a calculus. Excision of the mucocele and superficial parotidectomy was performed. The post-operative recovery was uneventful.

Fulltext Can bone wax cause cholesterol granuloma in the petrous apex? A case report

Wong EHC, Lim CC, Ong CA, Narayanan P

Int J Surg Case Rep, 2020;72:587-589.

PMID: 32698294 DOI: 10.1016/j.ijscr.2020.06.086

BACKGROUND: Cholesterol granuloma (CG) is a rare entity but is the commonest lesion in the petrous apex. They are associated with chronic ear disease and previous temporal bone surgery. While bone wax has been known to cause foreign body reaction due to its non-resorbable property in the mastoid, it has not been documented to cause CG formation.

CASE PRESENTATION: We described a 43 years old male who presented with a right mastoid swelling, nine years after a right retro-sigmoid craniotomy and excision for a cerebellopontine angle meningioma. He also had multiple cranial neuropathies involving trigeminal, facial and vestibulocochlear nerves. Temporal bone CT and MRI showed features suggestive of cholesterol granuloma with extensive bony erosions. He was treated with surgical excision and drainage where bone wax residues were found intraoperatively. Histopathological analysis of the lesion confirmed the diagnosis of cholesterol granuloma. Post-operatively, the mastoid swelling resolved and his recovery was uneventful.

CONCLUSION: Our case showed that CG could manifest as a complication of bone wax usage in a neurosurgical procedure. Even though further study is needed to draw a definitive conclusion on this theory, we believe this paper will contribute to the current literature as it is the only reported case of cholesterol granuloma with bone wax as the possible causative agent. This is important so that surgeons are aware of this potential complication and use this haemostatic agent more judiciously.

Solitary Extramedullary Plasmacytoma of the Sphenoid Sinus: A Case Report

Loong SP, Afandi AN, Lum CL, Ong CA

Indian J Otolaryngol Head Neck Surg, 2019 Nov;71(Suppl 3):1692-1694.

PMID: 31763226 DOI: 10.1007/s12070-015-0945-1

Solitary extramedullary plasmacytomas are rare, discrete mass of neoplastic monoclonal plasma cells in the soft tissue with no evidence of multiple myeloma. They constitute 3 % of all plasma cell tumors and less than 1 % of head and neck malignancies. A 43 year old lady presented to our clinic with complains of diplopia and headache for 4 weeks. Computed Tomography scan showed a mass lesion in the sphenoid sinus eroding the sinus floor, right wall, basisphenoid and parasellar area. A biopsy of the mass reported as plasmacytoma. Systemic examination revealed no evidence of dissemination of the disease confirming the diagnosis of a solitary extramedullary plasmacytoma. The patient was subjected to 25 fractions of radiotherapy. Here, we report a rare case of solitary extramedullary plasmacytoma of the sphenoid sinus.

An abnormal sigmoid sinus with a dire clinical implication

Puraviappan P, Prepageran N, Ong CA, Abd Karim R, Lingham OR, Raman R

Ear Nose Throat J, 2014 Jun;93(6):E55-6.

PMID: 24932833

Fulltext Nasopharyngeal Carcinoma Database

Pua KC, Khoo AS, Yap YY, Subramaniam SK, Ong CA, Gopala Krishnan G, et al.

Med J Malaysia, 2008 Sep;63 Suppl C:59-62.

PMID: 19230249

Nasopharyngeal carcinoma (NPC) is a cancer which is common in Asia. We report the establishment and early results of a multi-institutional prospective study of nasopharyngeal carcinoma, which seeks to systematically collect data as well as blood and tumour tissue samples from patients diagnosed with nasopharyngeal cancer at six centres in Malaysia. A total of 484 confirmed NPC cases were reported from the six participating centres between 1st July 2007 and 29th February 2008. Of these, 225 were newly diagnosed cases, 53 were recurrent cases and 206 were in remission at the time of reporting. Amongst the newly diagnosed cases, the most common presenting symptom was the presence of neck lumps (42%). Ophthalmo-neurologic symptoms were the presenting symptoms of 11% of the new cases. The majority of cases (75%) presented at stage III/IV.

Rice tungro bacilliform virus open reading frame 3 encodes a single 37-kDa coat protein

Marmey P, Bothner B, Jacquot E, de Kochko A, Ong CA, Yot P, et al.

Virology, 1999 Jan 20;253(2):319-26.

PMID: 9918890

Rice tungro bacilliform virus (RTBV) is a plant pararetrovirus and a member of the Caulimoviridae family and closely related to viruses in the Badnavirus genus. The coat protein of RTBV is part of the large polyprotein encoded by open reading frame 3 (ORF3). ORF3 of an RTBV isolate from Malaysia was sequenced (accession no. AF076470) and compared with published sequences for the region that encodes the coat protein or proteins. Molecular mass of virion proteins was determined by mass spectrometry (matrix-assisted laser desorption/ionization-TOF) performed on purified virus particles from three RTBV isolates from Malaysia. The N- and C-terminal amino acid sequences of the coat protein were deduced from the mass spectral analysis, leading to the conclusion that purified virions contain a single coat protein of 37 kDa. The location of the coat protein domain in ORF3 was reinforced as a result of immunodetection reactions using antibodies raised against six different segments of ORF3 using Western immunoblots after SDS-PAGE and isoelectrofocusing of proteins purified from RTBV particles. These studies demonstrate that RTBV coat protein is released from the polyprotein as a single coat protein of 37 kDa.

Fulltext A Novel Use of Modified Tracheostomy Tubes in Preventing External Auditory Canal Stenosis

Ng CS, Foong SK, Loong SP, Ong CA, Hashim ND

J Int Adv Otol, 2021 Jul;17(4):301-305.

PMID: 34309549 DOI: 10.5152/iao.2021.0078

BACKGROUND: Postoperative or post-traumatic canal restenosis in patients with external auditory canal (EAC) stenosis is a troublesome complication faced by many ear surgeons following canalplasty or meatoplasty. Many ear prostheses and surgical methods have been introduced to prevent the occurrence of such complication. Our aim in this study is to explore the feasibility of using modified non-fenestrated uncuffed tracheostomy tubes (TT) as postoperative stents after ear canal surgery.

METHODS: Canalplasty or meatoplasty was performed under general anesthesia via the posterior auricular transcanal approach. The EAC diameter and length were measured and a non-fenestrated uncuffed TT of suitable size was fitted into the ear canal. The TT was then modified during fitting, to fit onto the concha. Patients were advised on the importance of compliance. The adequacy of the size of the EAC after the surgery was assessed during follow-ups.

RESULTS: A total of 3 patients (4 ears) were included in our study. Various sizes of TTs were fitted into their EAC following canalplasty or meatoplasty. All of them showed excellent postoperative outcome on follow up 2 years after the surgery, with no evidence of postoperative EAC stenosis.

CONCLUSION: Modified TT stent after canalplasty or meatoplasty is proposed as an excellent alternative in preventing restenosis of EAC in centers with limited resources.

Fulltext Middle Ear Neuroendocrine Tumor Mimicking As Chronic Otitis Media

Sukumaran Y, Pol Ong Y, Siow Ping L, Ong CA, Narayanan P

Cureus, 2023 Jul;15(7):e42296.

PMID: 37609079 DOI: 10.7759/cureus.42296

Neuroendocrine neoplasms (NEN) of the head and neck are a rare and diverse group of tumors. Here, we report a case of a 40-year-old man presenting with symptoms resembling chronic left otitis media, including left ear otorrhea, otalgia, and reduced hearing. Otoscopic examination revealed a whitish mass located behind the tympanic membrane. The patient underwent examination under anesthesia and left cortical mastoidectomy, and a histopathological examination of the middle ear biopsy indicated the presence of an epithelial tumor with neuroendocrine differentiation, suggestive of middle ear adenoma. A staging CT scan performed three months after the mastoidectomy showed a hypodensity in the middle ear cavity, with no significant bony erosion, which could potentially indicate a residual or recurrent tumor. Consequently, a radical mastoidectomy was performed. The histopathological examination confirmed the presence of middle ear adenoma with neuroendocrine differentiation.

Fulltext A Genome Wide Study of Copy Number Variation Associated with Nasopharyngeal Carcinoma in Malaysian Chinese Identifies CNVs at 11q14.3 and 6p21.3 as Candidate Loci

Low JS, Chin YM, Mushiroda T, Kubo M, Govindasamy GK, Pua KC, et al.

PLoS One, 2016;11(1):e0145774.

PMID: 26730743 DOI: 10.1371/journal.pone.0145774

BACKGROUND: Nasopharyngeal carcinoma (NPC) is a neoplasm of the epithelial lining of the nasopharynx. Despite various reports linking genomic variants to NPC predisposition, very few reports were done on copy number variations (CNV). CNV is an inherent structural variation that has been found to be involved in cancer predisposition.

METHODS: A discovery cohort of Malaysian Chinese descent (NPC patients, n = 140; Healthy controls, n = 256) were genotyped using Illumina® HumanOmniExpress BeadChip. PennCNV and cnvPartition calling algorithms were applied for CNV calling. Taqman CNV assays and digital PCR were used to validate CNV calls and replicate candidate copy number variant region (CNVR) associations in a follow-up Malaysian Chinese (NPC cases, n = 465; and Healthy controls, n = 677) and Malay cohort (NPC cases, n = 114; Healthy controls, n = 124).

RESULTS: Six putative CNVRs overlapping GRM5, MICA/HCP5/HCG26, LILRB3/LILRA6, DPY19L2, RNase3/RNase2 and GOLPH3 genes were jointly identified by PennCNV and cnvPartition. CNVs overlapping GRM5 and MICA/HCP5/HCG26 were subjected to further validation by Taqman CNV assays and digital PCR. Combined analysis in Malaysian Chinese cohort revealed a strong association at CNVR on chromosome 11q14.3 (Pcombined = 1.54x10-5; odds ratio (OR) = 7.27; 95% CI = 2.96-17.88) overlapping GRM5 and a suggestive association at CNVR on chromosome 6p21.3 (Pcombined = 1.29x10-3; OR = 4.21; 95% CI = 1.75-10.11) overlapping MICA/HCP5/HCG26 genes.

CONCLUSION: Our results demonstrated the association of CNVs towards NPC susceptibility, implicating a possible role of CNVs in NPC development.

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