Bladder-Adherent Primary Appendiceal Carcinoma Masquerading as a Carpeting Rectal Lesion Detected by a Fecal Immunochemical Test: A Case Report

Introduction

Primary appendiceal carcinoma is rare and comprises up to 1% of all colorectal malignancies. Its invasion into adjacent organs, such as the bladder and rectum, especially as a presenting characteristic, is even less common.

Case Presentation

A 75-year-old asymptomatic male tested positive on a screening fecal immunochemical test (FIT). Colonoscopy showed a rectosigmoid tumor and normal appendiceal orifice. Staging MRI surprisingly showed that the cancer was, in fact, of appendiceal origin, coursed posteriorly to invade the rectosigmoid and form adhesions with the urinary bladder. Staging CT did not show metastatic disease. Low anterior resection, en bloc appendectomy, and right hemicolectomy were performed along with cystectomy and ileal conduit. Hematoxylin and eosin stains showed appendiceal adenocarcinoma invading through the appendiceal wall into the rectal muscularis and submucosa. Features of neuroendocrine carcinoma were not identified on immunohistochemistry. This was a colonic type of adenocarcinoma of the appendix.

Conclusion

This is a rare case of appendiceal carcinoma invading the rectum and presenting as a positive screening fecal immunochemical test in an asymptomatic individual. We effectively demonstrate the use of preoperative MRI to identify the appendiceal origin of the tumor, as well as to demonstrate the extent of tumor spread, which assisted with operative management and treatment planning.

Endophytic to total tumour volume ratio: An added variable to patients with T1b/T2 renal tumours undergoing partial nephrectomy

INTRODUCTION

Partial nephrectomy is the standard of care to patients with small renal masses. It is still encouraged to larger tumours whenever feasible. The aim of this study is to look for the endophytic to total tumour volume ratio as an added variable to study the complexity of partial nephrectomy to patients with T1b/ T2 renal tumours.

METHODS

Retrospective data collection of patients that had partial nephrectomy for T1b/T2 renal tumours by a single surgeon was done. Radiological re-assessment for the CT images to measure the endophytic to total tumour volume ratio was done.

RESULTS

The mean age of the patients was 63 years. The study included 25 males and 11 females. All cases were managed by open surgery using retroperitoneal transverse lateral lumbotomy and warm ischemia was used in all patients. The mean tumour volume was 74 cc, the mean endophytic tumour volume was 29 cc. The mean percentage of endophytic to total tumour volume was 42%.

CONCLUSIONS

Partial nephrectomy is safe for most of the patients with good performance status, having large renal masses. More complex surgery can be predicted in patients with endophytic to total tumour volume greater than 42%.

Thymic masses and mimics in adults: review of common and uncommon pathologies

The thymus is a primary lymphoid organ that plays a key role in the immune system development. Normally, it is located in the anterior mediastinum and it changes tissue composition with progressive fatty involution with age. The spectrum of pathological processes involving the thymus include enlargement, tumour development, and cystic change. In addition, other local pathology can mimic thymic disease. Differentiating these entities can be challenging; however, recognizing key features on imaging is essential to appropriately guide further investigation and therapy. The focus of this pictorial review will be to highlight the important distinguishing features of thymic hyperplasia, thymomas, thymic cysts, thymic neuroendocrine tumours (NETs), thymolipomas, mediastinal teratomas, and other mimics of thymic disease. Knowledge of the varying imaging findings on computed tomography and magnetic resonance imaging is valuable for radiologists to appropriately classify disease, avoid misdiagnosis, and expedite therapy.

Occult Amebic Liver Abscess as Cause of Extensive Inferior Vena Cava and Hepatic Vein Thrombosis

The most common extraintestinal complication of Entamoeba histolytica is amebic liver abscess (ALA). Hepatic vein and inferior vena cava (IVC) thrombosis are rare but well-documented complications of ALA, typically attributed to mechanical compression and inflammation associated with a large abscess. We present a case of a previously healthy 43-year-old Canadian man presenting with constitutional symptoms and right upper quadrant abdominal pain. He was found to have thrombophlebitis of the IVC, accessory right hepatic vein, and bilateral iliac veins. Extensive investigations for thrombophilia were negative. Magnetic resonance imaging of the liver demonstrated a 3.2-cm focal area of parenchymal abnormality that was reported as presumptive hepatocellular carcinoma, and a 1.9-cm lesion in the caudate lobe with diffusion restriction and peripheral rim enhancement. Despite multiple biopsy attempts, a histopathological diagnosis was not achieved. Abdominal pain and fever 4 months later prompted repeat ultrasound demonstrating a 10.4- × 12.0-cm rim-enhancing fluid attenuation lesion felt to represent a liver abscess. Thick dark "chocolate brown" drainage from the lesion and positive serology for E. histolytica confirmed the diagnosis of ALA acquired from a previous trip to Cuba. The patient was started on treatment with metronidazole and paromomycin and repeat abdominal ultrasound demonstrated resolution of the abscess. This case is the first to demonstrate extensive IVC thrombosis secondary to a relatively small occult ALA and emphasizes the thrombogenic potential of ALA. Amebic infection should be considered as a rare cause of IVC thrombosis in the correct clinical context.

Percutaneous radiofrequency ablation for osteoid osteoma: How we do it

AIMS AND OBJECTIVES

To describe our technique for performing radiofrequency ablation (RFA) in osteoid osteoma and to evaluate the results of treatment.

MATERIALS AND METHODS

We evaluated 40 patients in whom RFA was performed for osteoid osteomas between October 2005 and February 2008. The lesions were located in the femur (n = 22), tibia (n = 10), humerus (n = 2), acetabulum (n = 2), radius (n = 1), fibula (n = 1), patella (n = 1), and calcaneum (n = 1). The procedure was performed using a standard technique.

RESULTS

Technical success was achieved in all patients, with intranidal localization of the needle and complete ablation. All patients were fully weight bearing 2-3 h after the procedure. Successful pain relief was achieved in all patients within 48 h. Immediate complications included a case of minor thermal skin burn and a small cortical chip fracture, which healed on its own. There were no delayed complications. The average follow-up period was 12 months. Two patients (5% of cases) had recurrence of pain after intervals of 5 and 8 months, respectively, following the ablation; this was due to recurrence of the lesion. Complete pain relief was however achieved after a second ablation in both cases. Thus, our primary and secondary clinical success rates were 95 and 100%, respectively.

CONCLUSION

RFA is a safe, quick, minimally invasive, and extremely effective method for the management of osteoid osteomas.