The abdominal wall lumps and bumps: cross-sectional imaging spectrum

The Neoplastic Side of the Abdominal Wall: A Comprehensive Pictorial Essay of Benign and Malignant Neoplasms

Abdominal wall neoplasms are usually benign and, in the majority of these cases, no further work-up or treatment is indicated. The percentage of malignant abdominal neoplasms, however, is not negligible. Radiologists play a pivotal role in identifying imaging features that should favor malignancy, including larger lesion size, edema, neurovascular involvement, and peripheral or inhomogeneous dynamic enhancement, thus indicating to the clinician the need for further work-up. Histopathology is the reference standard for the characterization of abdominal wall neoplasms. In patients undergoing surgery, radiological assessment is needed to guide the surgeon by providing a comprehensive anatomic guide of the tumor extension. We present a pictorial review of benign and malignant abdominal wall neoplasms that can be encountered on radiological examinations, with a main focus on CT and MRI features that help in narrowing the differential diagnosis.

The Benign Side of the Abdominal Wall: A Pictorial Review of Non-Neoplastic Diseases

The abdominal wall is the location of a wide spectrum of pathological conditions, from benign to malignant ones. Imaging is often recommended for the evaluation of known palpable abdominal masses. However, abdominal wall pathologies are often incidentally discovered and represent a clinical and diagnostic challenge. Knowledge of the possible etiologies and complications, combined with clinical history and laboratory findings, is crucial for the correct management of these conditions. Specific imaging clues can help the radiologist narrow the differential diagnosis and distinguish between malignant and benign processes. In this pictorial review, we will focus on the non-neoplastic benign masses and processes that can be encountered on the abdominal wall on cross-sectional imaging, with a particular focus on their management. Distinctive sonographic imaging clues, compared with computed tomography (CT) and magnetic resonance (MR) findings will be highlighted, together with clinical and practical tips for reaching the diagnosis and guiding patient management, to provide a complete diagnostic guide for the radiologist.

Imaging of Abdominal Wall Masses, Masslike Lesions, and Diffuse Processes

Abdominal wall masses, masslike lesions, and diffuse processes are common and often incidental findings at cross-sectional imaging. Distinguishing among these types of masses on the basis of imaging features alone can be challenging. The authors present a diagnostic algorithm that may help in distinguishing different types of abdominal wall masses accurately. Hernias may mimic discrete masses at clinical examination, and imaging is often ordered for evaluation of a possible abdominal wall mass. Once a discrete mass is confirmed to be present, the next step is to determine if it is a fat-containing, cystic, or solid mass. The most common fat-containing masses are lipomas. Fluid or cystic masses include postoperative abscesses, seromas, and rectus sheath hematomas. Solid masses are the most common abdominal wall masses and include desmoid tumors, sarcomas, endometriomas, and metastases. Multiple masses and other diffuse abdominal wall processes are often manifestations of an underlying condition or insult. The most frequently found diffuse processes are multiple injection granulomas from administration of subcutaneous medication. This article offers an algorithmic approach to characterizing abdominal wall masses on the basis of their composition and reviews abdominal wall diffuse processes. Online supplemental material is available for this article. ^©RSNA, 2020.

CT and MRI features of tumors and tumor-like lesions in the abdominal wall

Masses involving the abdominal wall are common in clinical practice and have many etiologies, including tumors and tumor-like lesions. Abdominal wall tumors include primary and secondary tumors, the former of which constitute a heterogeneous group of soft tissue tumors with their own unique spectrum. Tumor-like lesions, such as hernias, are more common and must be distinguished from true tumors. Medical imaging is valuable for discovering, diagnosing, and evaluating the extent of abdominal wall masses. With the increasing application of computed tomography (CT) and magnetic resonance imaging (MRI), determining a diagnosis or narrowing the differential diagnosis is often possible, thus facilitating effective management. In this article, we comprehensively review the spectrum of common abdominal wall masses and present the CT and MRI features of typical cases in our hospital. A systematic stepwise diagnostic approach is also proposed for clinical practice.

A case of appendiceal mucinous cystadenoma which presented as painless purulent umbilical discharge

A 57-year-old obese, diabetic woman, presented with 1 day history of purulent umbilical discharge. She was vitally stable and afebrile. Abdominal examination revealed a full abdomen with purulent discharge from the umbilicus, swelling with erythema and induration surrounding the umbilicus. Lab tests were normal. Initial impression was abdominal wall abscess. Ultrasound showed subcutaneous fluid collection. Non-contrast CT showed collection and abdominal wall defect at the umbilicus. On exploration of the abscess cavity, there were two defects (umbilical and supraumbilical) with appendix protruding through the umbilical defect and a part of a small bowel and omentum adherent to the other defect. Wash was given, bowel and omentum were released and appendectomy was performed. Histopathology showed mucinous cystadenoma with periappendicitis. We would like to highlight the rare occurrence of an appendiceal mucinous cystadenoma in such a clinical presentation.

Umbilical Sebaceous Cyst Mimicking Infected Urachal Sinus

In addition to the most likely diagnoses for umbilical signs in adults (umbilical hernia, metastatic tumour, endometriosis, congenital abnormalities such as umbilical-urachal sinus and gallstones retained or spilled at the umbilicus), the differential diagnosis should also include epidermoid cyst arising from the skin of the umbilicus. We describe the case of a young man who presented with a persistent umbilical discharge which was initially thought to be umbilical-urachal sinus, but later found to be a sebaceous cyst.

Cesarean-Section Scar Endometrioma: A Case Report and Review of the Literature

Endometriomas can occur after any surgery where there is endometrial manipulation, and there are a number of reports of endometriomas developing in the abdominal wall at the site of the Pfannenstiel incision following Cesarean-section. Although this is ultimately a histopathologically-confirmed diagnosis, preoperative imaging including ultrasound, computed tomography, and magnetic resonance imaging may be helpful in the diagnosis and assessment. We report a pathology-confirmed case of Cesarean-section endometrioma with a classic, clinical presentation and imaging findings on computed tomography. A comprehensive literature review and discussion of the multi-modality imaging appearance of Cesarean-section endometrioma is also provided.

Sonography of Abdominal Wall Masses and Masslike Lesions: Correlation With Computed Tomography and Magnetic Resonance Imaging

Sonography is usually regarded as a first-line imaging modality for masses and masslike lesions in the abdominal wall. A dynamic study focusing on a painful area or palpable mass and the possibility of ultrasound-guided aspiration or biopsy are the major advantages of sonography. On the other hand, cross-sectional imaging clearly shows anatomy of the abdominal wall; thereby, it is valuable for diagnosing and evaluating the extent of diseases. Cross-sectional imaging can help differentiate neoplastic lesions from non-neoplastic lesions. This pictorial essay focuses on sonographic findings of abdominal wall lesions compared with computed tomographic and magnetic resonance imaging findings.