Fat misbehaving in the abdominal cavity: a pictorial essay

Endometriosis in Patients Undergoing Plastic Surgical Procedures: A Case Report and Review of the Literature

Background

Endometriosis is a common gynecological disorder described as the presence of functional endometrial tissue outside the uterus, which can also be found in extrapelvic locations. Although patients seeking treatment for endometriosis usually present to gynecologists, there are rare cases of endometriosis encountered by plastic surgeons in routine practice, either incidentally or as a concomitant finding.

Methods

We present a rare case of a 36-year-old woman with symptoms of panniculitis desiring panniculectomy. During surgery, an abdominal mass was excised and confirmed by pathological analysis to be endometriosis. A comprehensive literature review was conducted using the PubMed search engine of the National Institutes of Health to identify cases of endometriosis in plastic surgery. Following screening of the results, 14 articles were included in this analysis that fit the criteria of our search.

Results

Of the 14 articles reviewed, cutaneous endometriosis was the most common subtype found in plastic surgery. None of the studies described findings of endometriosis in routine panniculectomies. Several identified endometriosis discovered during cosmetic abdominoplasties.

Conclusions

Endometriosis encountered in plastic surgery is a rare but clinically important occurrence, with the cutaneous subtype representing the majority of cases. Endometriosis should always be on the differential diagnosis when an abdominal mass is found in a patient with a history of abdominal surgery. Abdominal masses found during routine aesthetic or reconstructive surgery should be submitted for tissue analysis to guide possible secondary treatments.

Focal necrosis of the falciform ligament as a rare cause of abdominal pain: A case report

The falciform ligament, a peritoneal fold that anatomically separates the right and left lobes of the liver, may infrequently be a cause of patients' complaints. In very rare instances, fatty appendages of the falciform ligament may undergo torsion, resulting in fat infarction. Despite its rarity, falciform ligament pathologies often mimic common abdominal issues, leading to misdiagnosis. Herein, we report a case of inflammation and necrosis of the falciform ligament in a 72-year-old female. The patient presented with abdominal pain, a positive Murphy's sign, and elevated inflammatory markers. Imaging, including a computed tomography (CT) scan, was pivotal in confirming the diagnosis of falciform ligament necrosis. Contrary to the proposed surgical approach (resection of the falciform ligament) in some reported cases, conservative management (including analgesia, hydration, and antibiotics) proved successful in this case. This report emphasizes the importance of considering falciform ligament torsion in upper abdominal pain differential diagnoses and highlights the key role of imaging for accurate diagnosis.

Characterization of hypermetabolic lymph nodes after SARS-CoV-2 vaccination using PET-CT derived node-RADS, in patients with melanoma

This study aimed to evaluate the diagnostic accuracy of Node Reporting and Data System (Node-RADS) in discriminating between normal, reactive, and metastatic axillary LNs in patients with melanoma who underwent SARS-CoV-2 vaccination. Patients with proven melanoma who underwent a 2-[18F]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (2-[18F]-FDG PET/CT) between February and April 2021 were included in this retrospective study. Primary melanoma site, vaccination status, injection site, and 2-[18F]-FDG PET/CT were used to classify axillary LNs into normal, inflammatory, and metastatic (combined classification). An adapted Node-RADS classification (A-Node-RADS) was generated based on LN anatomical characteristics on low-dose CT images and compared to the combined classification. 108 patients were included in the study (54 vaccinated). HALNs were detected in 42 patients (32.8%), of whom 97.6% were vaccinated. 172 LNs were classified as normal, 30 as inflammatory, and 14 as metastatic using the combined classification. 152, 22, 29, 12, and 1 LNs were classified A-Node-RADS 1, 2, 3, 4, and 5, respectively. Hence, 174, 29, and 13 LNs were deemed benign, equivocal, and metastatic. The concordance between the classifications was very good (Cohen's k: 0.91, CI 0.86-0.95; p-value < 0.0001). A-Node-RADS can assist the classification of axillary LNs in melanoma patients who underwent 2-[18F]-FDG PET/CT and SARS-CoV-2 vaccination.

Epiploic Adipose Tissue (EPAT) in Obese Individuals Promotes Colonic Tumorigenesis: A Novel Model for EPAT-Dependent Colorectal Cancer Progression

The obesity epidemic is associated with increased colorectal cancer (CRC) risk and progression, the mechanisms of which remain unclear. In obese individuals, hypertrophic epiploic adipose tissue (EPAT), attached to the colon, has unique characteristics compared to other fats. We hypothesized that this understudied fat could serve as a tumor-promoting tissue and developed a novel microphysiological system (MPS) for human EPAT-dependent colorectal cancer (CRC-MPS). In CRC-MPS, obese EPAT, unlike lean EPAT, considerably attracted colon cancer HT29-GFP cells and enhanced their growth. Conditioned media (CM) from the obese CRC-MPS significantly increased the growth and migration of HT29 and HCT116 cells (p < 0.001). In HT29 cells, CM stimulated differential gene expression (hOEC₈₆₇) linked to cancer, tumor morphology, and metabolism similar to those in the colon of high-fat-diet obese mice. The hOEC₈₆₇ signature represented pathways found in human colon cancer. In unsupervised clustering, hOEC₈₆₇ separated transcriptomes of colon cancer samples from normal with high significance (PCA, p = 9.6 × 10^-11). These genes, validated in CM-treated HT29 cells (p < 0.05), regulate the cell cycle, cancer stem cells, methylation, and metastasis, and are similarly altered in human colon cancer (TCGA). These findings highlight a tumor-promoting role of EPAT in CRC facilitated with obesity and establishes a platform to explore critical mechanisms and develop effective treatments.

Retroperitoneal Fat Necrosis in Response to an Episode of Acute Pancreatitis

Acute pancreatitis can result in fat necrosis, typically occurring in the peripancreatic region within weeks to months, and it generally appears as a low attenuation collection, with minimal heterogeneity. There are no specific imaging features that can diagnose retroperitoneal fat necrosis which may imitate other entities including certain malignancies, which may lead to invasive studies for diagnosis. Herein, we present a case of extensive retroperitoneal fat necrosis beyond the peripancreatic region that developed 10 days after an episode of acute pancreatitis.

Omental Infarction in a Child-Conservative Management as an Effective and Safe Strategy in Diagnosis and Treatment

Omental infarction (OI) is a rare disease occurring in children. Important risk factors include overweight and obesity. The clinical presentation is often non-specific, and the main symptom is acute abdominal pain. In addition, infarcted omentum may present with fever, anorexia, nausea, vomiting, diarrhea and dysuria. Due to the localisation of the pain, OI should be differentiated from acute appendicitis. The diagnosis of OI is sometimes made intraoperatively, during appendectomy for suspected acute appendicitis. Hence, it is important to state a correct preoperative diagnosis, which is commonly based on abdominal ultrasound and computed tomography. The treatment of OI is still inconclusive. Both conservative and surgical treatments are used. Both methods have their advantages and disadvantages. The decision of which treatment to follow should be multifactorial and include the patient’s clinical condition at the time of admission, the progression or regression of symptoms during hospitalization and laboratory and imaging findings. We present a clinical case of a 9-year-old overweight girl with OI, whose diagnosis was based on imaging diagnostics and enabled conservative treatment with no complications. The case we have described confirms that the conservative treatment is an effective and safe therapy.

Not only fat: omental infarction and its mimics in children. Clinical and ultrasound findings: a pictorial review

Acute abdominal pain in children is the most common cause of emergency department admissions. Omental infarction is a rare cause of acute abdominal pain in this age group, accounting for approximately 15% of cases in children and 0.024-0.1% of cases of surgery for suspected appendicitis at the same age. Its clinical presentation may mimic similar diseases such as acute appendicitis, epiploic appendagitis, and mesenteric panniculitis. Ultrasound is the modality of choice for the initial evaluation of acute abdominal pain in pediatric patients and it can be used with confidence in the diagnosis and management of omental infarction in children. In this brief review, we focus on the main ultrasound findings and their diagnostic clue for omental infarction and its mimics.

Not Just Fat: Imaging in Abdominal Fat Pathology

Fat in abdomen has diverse distribution and function. Insult to fat due to several causes can result in infarction or necrosis and present as acute abdomen clinically. Intra-abdominal focal fat infarction is one such condition that comprises of epiploic appendagitis, perigastric appendagitis, omental infarction, and torsion of fatty appendage of falciform ligament that have characteristic imaging features. Secondary causes of fat necrosis include pancreatitis or trauma related. Metabolic or responsive fat changes, like hypertrophy and dystrophy, can be diagnosed on imaging especially on computed tomography. Mesentric fat stranding including the mesentric panniculitis spectrum poses diagnostic dilemma and the causes and imaging role are covered in this review. Some infections and neoplasms that preferably affect abdominal fat compartments may mimic benign conditions, although some have specific patterns of involvement.