Features and diagnostic accuracy of fine needle aspiration cytology of thyroid nodules: retrospective study from Oman.

BACKGROUND: Fine needle aspiration cytology (FNAC) of the thyroid has been a reliable and cost-effective method for diagnosing thyroid disorders. Since FNAC results are usually operator dependent, there is a compelling need to explore FNAC accuracy among Omanis. OBJECTIVE: Describe cytological features of FNAC and assess FNAC accuracy compared to the postsurgical histopathology report. DESIGN: Retrospective diagnostic accuracy study SETTING: Tertiary care center. PATIENTS AND METHODS: Our study included adult Omani adult patients with thyroid nodules who underwent FNAC from 2014 to 2017 and had final pathology results for patients who underwent thyroid surgery. The results were classified according to the UK Royal college of Pathologists 'Thy' categories. Accuracy of FNAC was calculated by determining false and true positive and negative results based on histopathology findings. MAIN OUTCOME MEASURES: FNAC accuracy (sensitivity and specificity) compared to the postsurgical histopathology. SAMPLE SIZE: 867 patients with 1359 ultrasound guided FNACs of thyroid nodule; 137 underwent surgery. RESULTS: The mean age of the 867 patients was 43.7 (13.3) years, with a median of 42 years, and 87.8% were females. Out of 1359 FNACs, 1001 (73.7%) were benign (Thy2), 119 (8.8%) were atypia of undetermined significance or follicular lesion of undetermined significance (Thy3a), 31 (2.3%) were follicular neoplasm or suspicious for a follicular neoplasm (Thy3f), 52 (3.8%) were suspicious for malignancy (Thy4), 55 (4%) were malignant (Thy5), 101 (7.4%) as Unsatisfactory (Thy1). Only 137 patients underwent thyroid surgery, and the FNAC reports were compared with their final histopathology reports. The sensitivity, specificity and total accuracy of FNAC were 80.2%, 98.9% and 89.9%, respectively. The positive and negative predictive values of FNAC were 98.6% and 84.3%, respectively. CONCLUSION: Our study findings confirmed that FNAC of the thyroid is a sensitive, specific, and accurate initial tool for the diagnosis of thyroid lesions. Most of the FNACs were benign with a very low malignancy rate. Due to the minimal chance of false negative results and the slow-growing nature of thyroid malignancy, it is important that patients with benign FNAC should have periodic clinical and radiological follow-up. LIMITATIONS: Retrospective design and single-center study, and thyroid nodule size unavailable. CONFLICT OF INTEREST: None.

Neuroblastoma Among Omani Children: Clinical characteristics and survival outcome from a dedicated centre.

OBJECTIVES: A limited number of publications from the Middle East have focused on neuroblastoma, a common childhood malignancy. This study describes the clinical characteristics and survival outcome of Omani children with neuroblastoma treated at the National Oncology Centre, Oman, between 2010 and 2017. METHODS: From January 2010 to December 2017, data on Omani children aged less than 13 years with neuroblastoma were retrospectively collected. Survival data were statistically correlated with known prognostic factors, including age, stage of disease, MYCN profile and presence of metastasis. RESULTS: A total of 56 Omani children were included. in this study. The male to female ratio was 1:1. The mean age at presentation was one year and 10 months. The two most common presenting complaints were body masses (48.2%) and constitutional symptoms (33.9%). Approximately, 54.5% were high risk, 35.7% were intermediate risk and 9.8% were low risk. High-risk neuroblastoma was mainly found in children older than one year (76.6%), with low risk mainly observed in children less than one year of age (80%). The overall survival of all groups combined was 74% (P <0.05); the event-free survival (EFS) was 67% (P <0.05). The overall survival rates over five years for the high-risk, intermediate-risk and low risk groups were 60%, 88% and 100%, respectively, and the EFS was 51%, 79% and 100%, respectively. CONCLUSION: Omani children with neuroblastoma mainly presented with masses or constitutional symptoms and had an advanced disease at presentation which was associated with inferior survival. The survival outcomes were reasonably similar to published international data.

Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Hodgkin's Lymphoma: Diagnostic Challenge during COVID Vaccination.

Benign metabolic uptake on fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) is not uncommonly seen after immunization. We report a case of 30-year-old man with Hodgkin's lymphoma who underwent two cycles of chemotherapy. Interim 18F-FDG PET/computed tomography demonstrated complete metabolic response of prior hypermetabolic bilateral supraclavicular and mediastinal lymph nodes. Although multiple new normal-sized hypermetabolic left axillary and subpectoral lymph nodes are noted, relevant history revealed COVID vaccine 7 days prior scan with mild FDG uptake at the left deltoid muscle. These new findings at the left axilla are likely related to recent vaccination. 18F-FDG PET uptake in the lymph nodes is not so uncommon after immunization; relevant history is very important especially in the phase of massive immunization to avoid false interpretation.

Hereditary Paraganglioma in an Omani Family.

Pheochromocytomas are tumors derived from chromaffin cells within the medulla of adrenal glands, whereas paragangliomas are tumors derived from extra-adrenal chromaffin cells of the sympathetic prevertebral and paravertebral ganglia. The growing deployment of genetic testing has shown that approximately 30% of pheochromocytoma and paraganglioma (PPGL) patients carry familial pathogenic germline mutations in known PPGL-susceptibility genes. This prompts genetic screening of their family members and leads to an increase in the detection of asymptomatic PPGLs or non-secreting tumors reported in familial cases discovered after the index patient work-up. Here, we present three case reports of affected members of a single Omani family with a history of paraganglioma and highly variable clinical presentations among the affected members. Eight out of the 16 siblings (50.0%) in the second generation of the reported family pedigree were carriers of the succinate dehydrogenase B:c.574T>C mutation, reflecting the autosomal dominant inheritance risk of paraganglioma and other associated tumors. This report highlights the complexity of managing such families and encourages further discussion regarding the management of asymptomatic PPGL-associated mutation carriers. Genetic screening has enabled the early detection of PPGLs, for which early surgical intervention can significantly impact prognosis and treatment strategies to reduce morbidity and mortality. Although PPGLs are similar tumors, they warrant distinction from each other with respect to their differences in locations, manifestations, secretory functions, genetic syndromes, and propensity to metastasize. While current guidelines are clear concerning symptomatic PPGL cases, the management of asymptomatic mutation carriers requires further elucidation.

Prevalence of human papilloma virus in Oman: Genotypes 82 and 68 are dominating.

BACKGROUND: Persistent infection with high-risk (HR) HPV genotypes has been associated with cervical cancer, the third cancer affecting women in Oman with a crude incidence rate of 4.7 and mortality rate of 2.5 respectively. Other types of lower-risk (LR) HPV are associated with warts in both genders worldwide. OBJECTIVES: To assess the prevalence and genotype distribution of HPV and the risk factors among women with normal and abnormal cytology. METHODS: A cross sectional study conducted between September 2014 and April 2015. 258 cervical samples were obtained from women aged 18-68 years attending the Gynaecology Out-patient Clinic. HPV genotyping was performed using a multiplex real time-polymerase chain reaction (RT-PCR) assay. RESULTS: 22 different HPV genotypes were detected in 46 women (17.8%) and included 15 HR and 7 LR genotypes. Human immunodeficiency virus (HIV) patients (P = 0.052) and oral contraceptives users (P = 0.016) showed significant association with HPV infection. CONCLUSION: The most frequently observed HPV types were HR HPV 82 and LR HPV 54. These findings show that the predominant HPV genotypes in Oman are different from those seen in worldwide studies. This finding is important to determine the potential impact of preventive measures especially new vaccines to reduce the burden of cervical cancer.

Tc-99m HDP Single Photon Emission Computed Tomography/Computed Tomography in Stress Fracture of Base of Metatarsal Bone.

Proximal metatarsal stress fractures are common at base of the second metatarsal, typically seen in repetitive impact athletes, dancers, and those with cavus feet. It is caused by increased bone resorption rather than formation in a state of abrupt increased physical activity or intensity, leading to repetitive microfractures and eventually stress fracture. It is characterized by swelling and tenderness of a prolonged duration. We report a case of a 40-year-old female having left foot pain diagnosed with stress fracture on Tc-99m HDP single-photon emission computed tomography (SPECT)-CT. We emphasize the use of SPECT/CT in allocating active source of pain in the feet.

Evaluation of HE4, CA-125, Risk of Ovarian Malignancy Algorithm (ROMA) and Risk of Malignancy Index (RMI) in the Preoperative Assessment of Patients with Adnexal Mass.

OBJECTIVES: To evaluate the validity and compare the performance of cancer antigen-125 (CA-125), human epididymis protein 4 (HE4), the risk of malignancy index (RMI), and the risk of ovarian malignancy algorithm (ROMA) in the diagnosis of ovarian cancer in patients with ovarian lesions discovered during their preoperative work-up investigations. METHODS: This prospective, cross-sectional study looked at patients who attended the gynecology department at the Royal Hospital, Muscat, from 1 March 2014 to 30 April 2015, for the evaluation of an ovarian lesion. The inclusion criteria included women who underwent surgical intervention and who had a preoperative pelvic ultrasound with laboratory investigation for CA-125 and HE4. The study validated the diagnostic performance of CA-125, RMI, HE4, and ROMA using histopathological diagnosis as the gold standard. RESULTS: The study population had a total of 213 cases of various types of benign (77%) and malignant (23%) ovarian tumors. CA-125 showed the highest sensitivity (79%) when looking at the total patient population. When divided by age, the sensitivity was 67% in premenopausal women. In postmenopausal women, CA-125 had lower sensitivity (89%) compared to RMI, HE4, and ROMA (93% each). A high specificity of 90% was found for HE4 in the total patient population, 93% in premenopausal women and 75% in postmenopausal women. CA-125 had the highest specificity (79%) in postmenopausal women. Both CA-125 and RMI were frequently elevated in benign gynecological conditions particularly in endometriosis when compared to HE4 and ROMA. We also studied modifications of the optimal cut-offs for the four parameters. Both CA-125 and RMI showed a significant increase in their specificity if the cut-off was increased to ≥ 60 U/mL for CA-125 and to ≥ 250 for RMI. For HE4, we noted an improvement in its specificity in postmenopausal women when its cut-off was increased to140 pmol/L. CONCLUSIONS: HE4 and ROMA showed a very high specificity, but were less sensitive than CA-125 and RMI in premenopausal women. However, they were of comparable sensitivity in postmenopausal women and were valuable in distinguishing benign ovarian tumors or endometriosis from ovarian cancer. Modifying the cut-off values of the different markers resulted in a higher accuracy compared to the standard cut-offs, but at the expense of reduced sensitivity.

High Occurrence of Non-Clear Cell Renal Cell Carcinoma in Oman.

It is conventionally accepted that renal cell carcinoma (RCC) occurs in older patients and the clear cell type is the most common histology. However, ethnic variations exist and this study was carried out to determine the epidemiological pattern of RCC in Oman. Ninety RCC patients who presented to a tertiary care center in the Sultanate of Oman from 2010 to 2014 were studied. The main findings were that the median age of presentation was low, more patients presented with localized stage, and there was a higher incidence of non-clear (especially papillary) histology. Data from other Gulf countries and possible reasons for the different profile are discussed.

Validity of Cancer Antigen-125 (CA-125) and Risk of Malignancy Index (RMI) in the Diagnosis of Ovarian Cancer.

OBJECTIVE: We sought to determine the validity of cancer antigen 125 (CA-125) and the risk of malignancy index (RMI) in the diagnosis of ovarian cancer in women presenting with adnexal lesions of various histopathology types. METHODS: This retrospective cross- sectional study included all women with adnexal lesions who were evaluated at the Royal Hospital, Oman, between January 2012 and December 2014. The inclusion criteria included women who underwent surgical intervention and who had preoperative CA-125 testing and pelvic ultrasound in the work-up plan of their management. The surgical intervention was usually followed by a histopathological diagnosis of the nature of the lesion, which was used as the gold standard for the evaluation of both CA-125 and RMI. RESULTS: The cohort included 361 women who had serum CA-125 and pelvic ultrasound prior to the surgical intervention of the adnexal lesion. Of these women, 61 (17%) had malignant ovarian lesions. Using the proposed cut-off 35 U/ml for CA-125 and 200 for RMI, the CA-125 test was more sensitive for detecting the majority of malignant ovarian tumors compared to the RMI (69% vs. 57%). Both tests were more sensitive in detecting epithelial ovarian cancer compared to other ovarian cancers. However, RMI was more specific in excluding benign ovarian lesions compared to CA-125 (81% vs. 68%). Additionally, RMI had a better area under the curve compared to CA-125 (0.771 vs. 0.745; p<0.005). Lowering the RMI cut-off to 150 resulted in a better sensitivity (62% vs. 57%) and had an acceptable specificity (78% vs. 81%) compared to a cut-off of 200. CONCLUSION: Both CA-125 and RMI have good validity in the diagnosis of ovarian tumors. CA-125 has higher sensitivity; however, RMI has higher specificity. In combination, CA-125 might be more valid for the diagnosis of malignant ovarian cancer while RMI is more valid for excluding the diagnosis of these tumors. Differential use of these two tools will improve the triage of women with suspected ovarian tumors since both are measured in their work-up. We recommended the use of both tools in primary care to reduce referral to gynecology or oncology units.

Eosinophilic Pneumonia in a Patient with Bronchial Myiasis: Case report and literature review.

Pulmonary myiasis is an unusual form of myiasis in humans and has been recently identified as a cause of eosinophilic pneumonia. We report the case of a 13-year-old Omani boy who presented to the Royal Hospital, Muscat, Oman, in October 2014 with respiratory distress. Bronchial aspirates revealed features of eosinophilic pneumonia. Possible larvae identified in the cytology report, a high immunoglobulin E level and the patient history all indicated bronchial myiasis. The patient was treated with steroids and ventilation and has since been disease-free with no long-term side-effects. To the best of the authors' knowledge, this is the first case of bronchial myiasis in Oman.

Renal mass: is it always worrisome?

SUMMARY: 10-month male with large abdominal mass.