A challenging case of sporadic melanocytoma of the jugular foramen.

BACKGROUND: The jugular foramen (JF) can be the site of several tumours. Paragangliomas, schwannomas and meningiomas are the most commonly reported. We describe a case of melanocytoma originating from the JF and presenting with an accessory nerve palsy. ILLUSTRATIVE CASE: A 48-year-old woman presented with a 6-month history of cervical and left shoulder pain with wasting and weakness of the left trapezius. A Magnetic Resonance Imaging (MRI) showed a T1-hyperintense, T2-isointense, heterogeneously enhancing lesion involving the left JF and extending into the cerebello-medullary and cerebello-pontine cisterns. A retrosigmoid craniotomy was performed and a near-total removal achieved. The accessory nerve was involved by tumour and could not be preserved. Given the diagnostic uncertainty between melanotic schwannoma, metastatic melanoma and meningeal melanocytoma, next generation sequencing and genome-wide DNA methylation arrays were performed, documenting a mutation in GNA11 (c.6226A>T, p. Gln209Leu) and a methylation profile consistent with melanocytoma. The patient underwent adjuvant fractionated radiotherapy of the tumour remnant. A follow-up MRI 4 years after surgery did not show any tumour recurrence. CONCLUSIONS: The differential diagnosis of skull base pigmented tumours can be challenging, particularly when they occur in unusual locations such as the JF. They can be misdiagnosed given their similar clinical, neuroradiological and pathological features if anatomy of the site of origin is not carefully considered and molecular tests are not performed, leading to erroneous treatment and follow-up planning.

Predictors of thalassaemia carriers in Trinidad and Tobago

OBJECTIVE: To determine possible predictors of thalassaemia carriers among prospective blood donors in Trinidad and Tobago. DESIGN AND METHODS: 460 prospective blood donors were screened for microcytosis (MCV<83fL) by performing a complete blood count (CBC) using a Sysmex XE-2100. The 86 samples with microcytosis further had a blood film analysis, iron studies, haemoglobin electrophoresis, haemoglonin F and A2 quantification, and DNA analysis for thalassaemia mutations. Statistical analysis was done using SPSS to determine predictors of thalassaemia trait. The variables tested were ethnicity, haemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin volume (MCHC), red blood cell (RBC), RBC distribution width (RDW-SD and RDW-CV). We looked at different mathematical formulae to predict thalassaemia trait ie the Mentzer Index, Shine and Lal Index, Green and King Index, Srivastava Index, RDW Index and the red cell indices tested were RDW-CV, RDW-SD and RCC. RESULTS: 86 (18.7%) subjects had microcytosis. 44(51.2%) of these had DNA results. 31(70.5%) had thalassaemia trait: 25(80.6%) with genotype –α/αα, 4(12.9%) α-/α-(all α3.7), one IVS I-5 G/C and one IVSII-666 T/C. The MCV, RDW-SD and RDW-CV were useful in predicting thalassaemia trait. RDW-SD identified 30 (96.8%) of the 31 carriers, the Green and King formula identified 27 (87.1%), and Ricerca index identified all 31 (100%). CONCLUSION: MCV, RDW-SD, Green and King formula and Ricerca index may be useful predictors of thalassaemia trait in Trinidad and Tobago.

Perceptions of Caribbean type 2 diabetes patients on self-monitoring of blood glucose.

CONTEXT: The views of type 2 diabetes (T2DM) patients have not been considered in the debate on the role of self-monitoring of blood glucose (SMBG) in the management of T2DM. OBJECTIVE: To assess the views of T2DM patients on SMBG. METHODS: Two previously trained research assistants used a structured pre-tested questionnaire to interview 416 T2DM patients practising SMBG in out-patient clinics in the privacy of the patients after they have consented to be interviewed. RESULTS: 79% of patients were unemployed with mean duration of diabetes of 11.8 ± 0.5 year. 94% of patients did not have health insurance policies while 86% did not belong to any diabetes support group. Although 70% of the patients identified SMBG as expensive, 94% believed it assists glycaemic control, while 89% thought it was worth the expense. CONCLUSION: Caribbean T2DM patients believe SMBG was beneficial for the management of their diabetes and empowering them may reduce diabetes complications.

Effect of cataract on a scotopic sensitivity screening test for glaucoma.

We investigated whether cataract decreases whole-field scotopic sensitivity, a measurement used for the detection of early glaucoma damage. The study population consisted of 33 patients scheduled for cataract surgery. Patients were >/=50 years old and had no ocular disease except senile cataract. The whole-field scotopic sensitivity of one eye of each subject was measured 1 day before and 3 months after cataract surgery. That of six persons of similar age without cataract was also measured twice, 3 months apart. Cataract extraction was associated with significantly improved sensitivity (p = 0.005). With stratification by cataract type, only persons with nuclear sclerosis demonstrated a significantly improved sensitivity after cataract surgery (p = 0.03). The magnitude of sensitivity improvement after surgery did not differ significantly between patients with mild compared to moderate cataract. Multiple regression analysis revealed that age, preoperative intraocular pressure, change in visual acuity, cataract type, and cataract severity were not independently significant predictors of change in sensitivity after cataract surgery. We conclude that cataract may alter the whole-field scotopic sensitivity score and may need to be taken into account in its use for glaucoma screening.