What the radiologist needs to know: the role of preoperative computed tomography in selection of operative approach for adrenalectomy and review of operative techniques

Adrenalectomy is the standard of care for management of many adrenal tumor types and, in the United States alone, approximately 6000 adrenal surgeries are performed annually. Two general approaches to adrenalectomy have been described; (1) the open approach, in which a diseased adrenal is removed through a large (10–20 cm) abdominal wall incision, and (2) the minimally invasive approach, in which laparoscopy is used to excise the gland through incisions generally no longer than 1–2 cm. Given these disparate technique options, clear preoperative characterization of those specific disease features that inform selection of adrenalectomy approach is critically important to the surgeon. Because most of these features are directly assessed via preoperative abdominal imaging, in particular computed tomography (CT) scanning, a clear mutual understanding among surgeons and radiologists of those adrenal tumor features impacting operative approach selection is vital for planning adrenal surgery. In this context, we review the preoperative CT imaging features that specifically inform adrenalectomy approach selection, provide illustrative examples from our institution’s imaging and surgical archives, and provide a stepwise guide to both the open and laparoscopic adrenalectomy approaches.

     

CT of malignant peripheral nerve sheath tumor

Malignant peripheral nerve sheath tumors are soft tissue sarcomas that typically arise from a neurofibroma. Patients with neurofibromatosis type 1 represent approximately half of the population diagnosed with these tumors. This autosomal-dominant genetic disorder is distinguished by loss-of-function mutations in the neurofibromin 1 gene, which ultimately promotes atypical cellular proliferation. These biologically aggressive tumors are associated with a poor prognosis as they are resistant to available therapies and have high rates of recurrence, progression, and mortality. In this article, we report the case of a 45-year-old male with a history of neurofibromatosis type 1 who was diagnosed with a malignant peripheral nerve sheath tumor. We focus on optimizing diagnosis and treatment through the application of radiological imaging modalities, including cinematic rendering.     

Removal of Abnormal Myofilament O-GlcNAcylation Restores Ca2+ Sensitivity in Diabetic Cardiac Muscle

Contractile dysfunction and increased deposition of O-linked β-N-acetyl-d-glucosamine (O-GlcNAc) in cardiac proteins are a hallmark of the diabetic heart. However, whether and how this posttranslational alteration contributes to lower cardiac function remains unclear. Using a refined β-elimination/Michael addition with tandem mass tags (TMT)–labeling proteomic technique, we show that CpOGA, a bacterial analog of O-GlcNAcase (OGA) that cleaves O-GlcNAc in vivo, removes site-specific O-GlcNAcylation from myofilaments, restoring Ca²⁺ sensitivity in streptozotocin (STZ) diabetic cardiac muscles. We report that in control rat hearts, O-GlcNAc and O-GlcNAc transferase (OGT) are mainly localized at the Z-line, whereas OGA is at the A-band. Conversely, in diabetic hearts O-GlcNAc levels are increased and OGT and OGA delocalized. Consistent changes were found in human diabetic hearts. STZ diabetic hearts display increased physical interactions of OGA with α-actin, tropomyosin, and myosin light chain 1, along with reduced OGT and increased OGA activities. Our study is the first to reveal that specific removal of O-GlcNAcylation restores myofilament response to Ca²⁺ in diabetic hearts and that altered O-GlcNAcylation is due to the subcellular redistribution of OGT and OGA rather than to changes in their overall activities. Thus, preventing sarcomeric OGT and OGA displacement represents a new possible strategy for treating diabetic cardiomyopathy.     

May–Thurner syndrome: MDCT findings and clinical correlates

May–Thurner syndrome (MTS) is a venous compression syndrome in which the left common iliac vein is compressed between the lower lumbar spine and the right common iliac artery. While asymptomatic compression is very common, the process can lead to morbidity in selected individuals, most commonly deep venous thrombosis (DVT) and the sequelae thereof. Radiologists must recognize the diagnosis because of the unique management, which differs from DVT without iliac vein compression. The current pictorial essay will review the pathophysiology, imaging, and treatment of MTS.     

Distinct cases of gangliocytic paraganglioma in the duodenum: Two case reports

Gangliocytic paraganglioma (GP) is a rare, benign neuroendocrine tumor that commonly arises in the second portion of the duodenum. Despite its favorable prognosis, there have been instances of lymph node and liver metastasis as well as 1 reported fatal case. The immunohistochemical and morphological resemblance between GP and neuroendocrine tumor G1 makes it critical to properly recognize and differentiate between the 2. In this article, we present 2 distinct cases of GP: a 70-year-old male with a GP tumor in the ampulla, and a 46-year-old male with a GP near the ampulla whose tumor was excised using a robotic Whipple procedure. We focus on optimizing diagnosis and management through the application of radiological modalities and pathological analysis.     

Colorectal leiomyosarcoma: A case report

Leiomyosarcomas are rare aggressive smooth muscle tumors that represent 0.1% of all colorectal malignancies. The lack of literature available concerning leiomyosarcomas presents a challenge when diagnosing and treating these tumors, thus it is crucial that we differentiate them from gastrointestinal stromal tumors (GIST), the most common type of mesenchymal neoplasms of the gastrointestinal (GI) tract, especially when considering leiomyosarcoma''s high prevalence of recurrence and malignancy. In this article, we present a case of a 74-year-old male with a diagnosis of colonic leiomyosarcoma. We analyze the tumor''s CT imaging findings as well as correlation with the patient''s pathological findings including immunostains, size, and mitotic activity, as well as the patient''s risk for recurrence.     

Wandering spleen with torsion and infarction: A case report

Wandering spleen, also known as ectopic spleen, is a rare condition in which the spleen''s anatomical location is other than its fixed position in the abdomen''s left upper quadrant. The cause of such an abnormality could be due to congenital or acquired factors, which could ultimately lead to torsion and splenic infarct. Given the nonspecific clinical symptoms and the potential complications associated with wandering spleen, computed tomography scans provide a crucial means for proper diagnosis. In this article, we report the case of a 16-year-old female with a diagnosis of wandering spleen with torsion and splenic infarct.