Middle Ear Neuroendocrine Tumor Mimicking As Chronic Otitis Media.

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.

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

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.

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

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.

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.

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.

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.

Cochlin in normal middle ear and abnormal middle ear deposits in DFNA9 and Coch (G88E/G88E) mice.

DFNA9 sensorineural hearing loss and vestibular disorder, caused by mutations in COCH, has a unique identifying histopathology including prominent acellular deposits in cochlear and vestibular labyrinths. A recent study has shown presence of deposits also in middle ear structures of DFNA9-affected individuals (McCall et al., J Assoc Res Otolaryngol 12:141-149, 2004). To investigate the possible role of cochlin in the middle ear and in relation to aggregate formation, we evaluated middle ear histopathology in our Coch knock-in (Coch (G88E/G88E) ) mouse model, which harbors one of the DFNA9-causative mutations. Our findings reveal accumulation of acellular deposits in the incudomalleal and incudostapedial joints in Coch (G88E/G88E) mice, similar to those found in human DFNA9-affected temporal bones. Aggregates are absent in negative control Coch (+/+) and Coch (-/-) mice. Thickening of the tympanic membrane (TM) found in humans with DFNA9 was not appreciably detected in Coch (G88E/G88E) mice at the evaluated age. We investigated cochlin localization first in the Coch (+/+)mouse and in normal human middle ears, and found prominent and specific cochlin staining in the incudomalleal joint, incudostapedial joint, and the pars tensa of the TM, which are the three sites where abnormal deposits are detected in DFNA9-affected middle ears. Cochlin immunostaining of Coch (G88E/G88E) and DFNA9-affected middle ears showed mutant cochlin localization within areas of aggregates. Cochlin staining was heterogeneous throughout DFNA9 middle ear deposits, which appear as unorganized and overlapping mixtures of both eosinophilic and basophilic substances. Immunostaining for type II collagen colocalized with cochlin in pars tensa of the tympanic membrane. In contrast, immunostaining for type II collagen did not overlap with cochlin in interossicular joints, where type II collagen was localized in the region of the chondrocytes, but not in the thin layer of the articular surface of the ossicles nor in the eosinophilic deposits with specific cochlin staining.

Quantitative polarized light microscopy of unstained mammalian cochlear sections.

Hearing loss is the most common sensory deficit in the world, and most frequently it originates in the inner ear. Yet, the inner ear has been difficult to access for diagnosis because of its small size, delicate nature, complex three-dimensional anatomy, and encasement in the densest bone in the body. Evolving optical methods are promising to afford cellular diagnosis of pathologic changes in the inner ear. To appropriately interpret results from these emerging technologies, it is important to characterize optical properties of cochlear tissues. Here, we focus on that characterization using quantitative polarized light microscopy (qPLM) applied to unstained cochlear sections of the mouse, a common animal model of human hearing loss. We find that the most birefringent cochlear materials are collagen fibrils and myelin. Retardance of the otic capsule, the spiral ligament, and the basilar membrane are substantially higher than that of other cochlear structures. Retardance of the spiral ligament and the basilar membrane decrease from the cochlear base to the apex, compared with the more uniform retardance of other structures. The intricate structural details revealed by qPLM of unstained cochlear sections ex vivo strongly motivate future application of polarization-sensitive optical coherence tomography to human cochlea in vivo.

Two-photon microscopy of the mouse cochlea in situ for cellular diagnosis.

Sensorineural hearing loss is the most common type of hearing loss worldwide, yet the underlying cause is typically unknown because the inner ear cannot be biopsied today without destroying hearing, and intracochlear cells have not been imaged with resolution sufficient to establish diagnosis. Intracochlear imaging has been technologically challenging because of the cochlea's small size and encasement in bone. We report, for the first time, imaging of the mouse cochlea in situ without exogenous dyes, through a membranous round window, using a near-infrared femtosecond laser as the excitation and endogenous two-photon excitation fluorescence (TPEF) and second harmonic generation as the contrast mechanisms. We find that TPEF exhibits strong contrast allowing cellular, and even subcellular resolution, and detection of specific, noise-induced pathologic changes. Our results demonstrate that the round window provides a useful access to the cochlea through the middle ear, and they motivate future development of a new and efficient diagnostic tool based on two-photon micro-endoscopy.