Epidermoid cyst of the presacral space is a rare congenital lesion of ectodermal origin. Presacral epidermoid cysts have been previously reported in women, however are extremely rare in males. We report a case of presacral epidermoid cyst in a 55-year-old male who presented to our emergency department with acute urinary retention and history of chronic constipation. A non-contrast computed tomography scan was performed with suspicion of urolithiasis, which revealed a well circumscribed low attenuation presacral mass. Magnetic resonance imaging (MRI) of the pelvis was subsequently performed to further characterize the lesion. The mass was returning hypointense T1 and hyperintense T2 signals with few foci of T2 hypointensities. There was no post-contrast enhancement; however the lesion was showing diffusion restriction, appearing hyperintense on diffusion weighted imaging (DWI) and hypointense on the corresponding apparent diffusion coefficient map. These imaging features were consistent with an epidermoid cyst. Laparotomy with complete surgical excision of the cyst and preservation of the adjacent structures was performed. The histopathology confirmed the diagnosis. This case highlights the importance of MRI with additional sequences of diffusion weighted imaging which can be helpful to differentiate, to a good degree of confidence, among different pelvic tumors, therefore obviating the need of biopsy before surgery.

Introduction Breast density on mammography can affect the sensitivity of breast cancer detection and is an independent risk factor for breast cancer. The incidence of breast cancer in Pakistani women is reported to be the highest among women in Asia. No published data is describing the patterns of mammographic breast density in this population. We undertook this study to assess the Breast Imaging Reporting and Data System (BI-RADS) patterns of breast density on mammography, factors that affect breast density, and inter-observer variability in breast density assessment. Methods Bilateral breast mammograms were retrospectively reviewed for breast density by two separate readers (resident and attending radiologist). Breast density was categorized into four types according to the BI-RADS lexicon. Types 1 and 2 were grouped into non-dense and types 3 and 4 into dense breasts. The association of patient factors with breast density was assessed, with p < 0.05 considered statistically significant. The inter-observer variability in breast density assessment between the two readers was calculated using Cohen's κ coefficient. Results A total of 612 women underwent mammography in the study period. Type 3 (heterogeneously dense breast parenchyma) was the most frequent pattern (51.6%) followed by type 2 (scattered fibroglandular) pattern (38.9%). Fatty parenchyma (type 1) and extremely dense parenchyma (type 4) were the least common. Breast density was inversely related to age (p < 0.001) and parity (p <0.002). Breast density was also lower in postmenopausal women (p < 0.001). There was no statistically significant difference in mean age at menarche, age at first delivery, family history of breast cancer, or presence of cancer among women with dense and non-dense breasts. The inter-observer agreement was almost perfect (κ = 0.86). Conclusion The majority of women in our population (56.9%) had dense breasts (BI-RADS type 3 and 4) which decrease the sensitivity of breast cancer detection on mammography suggesting it may be insufficient as the sole screening/diagnostic tool in this population. Lower breast density was associated with increasing age, parity, and post-menopausal status. Breast density assessment was almost perfect among the resident and attending radiologist.

Osteochondroma and synovial chondromatosis are frequently reported benign bony and cartilaginous lesions. Osteochondroma is distinguished by a cartilage-capped bony exostosis on the exterior surface of the bone, whereas synovial chondromatosis is secondary to metaplasia and is characterized by multiple cartilaginous loose bodies within the synovium. We present an atypical case of synovial chondromatosis developing in a bursa sec­ondary to an underlying osteochondroma of the proximal medial tibia in a child. It is extremely rare to see both these conditions occurring in one location simultaneously. Moreover, this association is an unusual occurrence in the pediatric age group. The patient underwent surgical excision of the lesions and the final diagnosis was confirmed on histology. Simulation to malignant degeneration is often observed and vigilant assessment of both lesions is essential to exclude the possibility of sarcomatous transformation in those who present with these conditions since clinical, radiological, and histopathological features may overlap. However, a proper preoperative distinction may prevent an unnecessary aggressive therapeutic approach, which stood true for our case.

Open Access Original Article

Introduction Trauma constitutes a major public health problem. Ninty percent of world's fatalities on road occur in low and middle-income countries. Focused assessment with sonography in trauma (FAST) has a key role in trauma investigation, altering subsequent management in a significant number of patients. There is a rising trend of introducing FAST examination to non-radiologists and junior members of healthcare team to hasten triage of trauma patients. Objective To determine interobserver agreement on focused assessment with sonography for trauma in blunt abdominal injury between senior and junior residents. Methods This cross-sectional study was conducted at Aga Khan University Hospital. Three hundred patients with blunt abdominal trauma meeting inclusion criteria were enrolled. FAST was performed using standard curvilinear 3.5-5 MHz transducer. Agreement between junior and senior residents was measured and Kappa statistic was calculated. Results Mean age of the patients included in the study was 30.04 ± 18.09 years. Among these 237 (79%) were male and 63 (21%) were female. Sixteen (5.3%) were positive for intraperitoneal free fluid while the remaining 284 (94.7%) were negative. A total of 19 FAST examinations were reported positive by junior residents, of which 15 (78.9%) were confirmed by a senior resident to be correct, while four (21.05%) were falsely labeled positive by a junior resident. A total of 281 negative FAST examinations were reported by junior residents, of which 280 (99.6%) were confirmed by a senior resident, while only one (0.003%) was falsely labeled negative. Kappa statistic was calculated for inter-observer agreement on FAST examination findings, which showed a kappa value of 0.84 (very good agreement), with a p-value of <0.001. Conclusion Our study suggests very good interobserver agreement on FAST examination between senior and junior resident in patients with blunt trauma to the abdomen. Results suggest that FAST can be easily learnt with minimal radiology training and may have greater applicability in trauma.