Inhibition of Adipocyte Necroptosis Alleviates Fat Necrosis and Fibrosis After Grafting in a Murine Model.

BACKGROUND: Because of the delicate structure of the adipose tissue, fat necrosis accounts for 43.7% of all complications after autologous fat grafting; however, its regulation remains unclear. OBJECTIVES: The purpose of this study was to examine the role of necroptosis in fat graft remodeling after grafting. METHODS: Clinical fat graft necrosis samples were collected, and the expression levels of the necroptosis marker phosphorylated(p)-MLKL were analyzed. Transcriptome analysis was performed on fat grafts before and 1 week after transplantation in C57BL/6 mouse fat grafting models. Additionally, the in vivo effects of RIPK1 inhibitor Nec-1s or RIPK3 inhibitor GSK'872 on the fat grafting complications, including fat necrosis and fibrosis, were investigated. RESULTS: Necroptosis markers were observed and associated with higher occurrence of fibrosis in clinical fat graft necrosis samples compared to normal fat tissue. Amplification and RNA-Seq were conducted on RNA isolated from fat grafts before and after grafting. MLKL, RIPK1, and RIPK3's expression levels were significantly upregulated in comparison to controls. Higher expression levels of necroptotic RNAs were associated with higher levels of DAMPs, including Cxcl2, HMGB1, S100a8, S100a9, Nlrp3, and IL33, and activated proinflammatory signaling pathways, including the TNF, NF-kappa B, and chemokine signaling pathways. Necroptotic inhibitor Nec-1s and GSK'872 robustly suppressed the p-MLKL expression level and significantly inhibited necroptotic cell death, especially in adipocytes. Moreover, administration of Nec-1s and GSK'872 significantly alleviated fat necrosis and subsequent fibrosis in fat grafts. CONCLUSIONS: Collectively, our study findings highlight the potential therapeutic applications of necroptosis inhibitors in preventing fat necrosis and fibrosis after grafting.

Congenital liquified subcutaneous fat necrosis in a newborn: an unusual case.

Subcutaneous fat necrosis of the newborn is a self-limited disorder of the panniculus that arises in the first six weeks of life. Some differential diagnoses may be difficult such as bacterial cellulitis or erysipelas. The prognosis is usually favorable but there are serious complications for which the patient must be regularly monitored, especially hypercalcemia. We report a case of a full-term newborn with a liquidated area of subcutaneous fat necrosis. A surgical incision was performed because of the discomfort and the lack of regression. Hypercalcemia and nephrocalcinosis appeared afterward. A set of clinical, biological, and histological arguments allows the diagnosis of subcutaneous fat necrosis. Follow-up to early detection and to manage such complications is necessary.

Radiologic-histopathologic correlation of fatty island sign with fat necrosis in atypical lipomatous tumor and lipoma.

AIM: This study aimed to assess the imaging features of atypical lipomatous tumors (ALTs) and lipoma with fat necrosis. METHODS: This study included patients with histopathologically proven fat necrosis within adipocytic tumors who underwent preoperative imaging. Magnetic resonance imaging (MRI) and/or computer tomography (CT) findings of fat necrosis associated with lipomatous tumors were retrospectively reviewed, emphasizing the "fatty island sign (FIS)." FISs were defined as well-demarcated, focal fat-containing areas surrounded by more thickened septa compared with other intratumoral septa. Imaging findings of FIS were compared between ALT and lipoma. RESULTS: Fat necrosis was histopathologically confirmed in 17 patients (6 ALTs and 11 lipomas). Among them, 18 FISs were observed in 10 lesions (59%). Multiple FISs within a lesion were observed in 4 (40%) patients. The median maximum diameter of the FISs was 37 mm. Hypointense areas within FISs relative to the subcutaneous fat on T1- and T2-weighted images were observed in 8 (80%) and 9 (90%), respectively, whereas hyperintense areas within FISs on fat-suppressed T2-weighted images were observed in 2 (20%). Nonfatty solid components within FISs were observed in 2 (20%). On CT, increased fat attenuation and pure fat attenuation within FISs were observed in 6 (86%) and 1 (14%), respectively. The imaging findings of FIS were not significantly different between ALT and lipoma. CONCLUSION: FISs were observed in 59% of the histologically proven ALT and lipoma patients with fat necrosis. The hypointense areas relative to the subcutaneous fat on T1- and T2-weighted images and increased fat attenuation on CT were usually observed within FISs.

Subcutaneous fat necrosis of the newborn: A systematic review of surgical management and outcomes.

BACKGROUND: Subcutaneous fat necrosis of the newborn (SCFN) is a rare form of panniculitis manifesting as erythematous plaques or nodules at sites of brown fat in neonates. Surgical management may be indicated in severe cases; however, there is a paucity of literature compiling presentations and outcomes of these surgical patients. METHODS: The authors performed a systematic review, in consultation with a licensed librarian, on MEDLINE and Embase for studies including patients with SCFN who were surgically managed. RESULTS: The search strategy generated 705 results, among which 213 (30.2%) were excluded for lack of discussion on surgical management. Twenty-two studies discussed surgical management of SCFN in 26 patients, but in 6 of these studies the patients were not surgically managed. Ultimately, 16 articles with 16 patients who were surgically managed were included in the study. Average age at diagnosis was 11.8 ± 9.8 days; average age at surgery was 39.5 ± 70.4 days. The most common etiologies were "unknown" (6, 37.5%), therapeutic hypothermia (4, 25.0%), and birth complications (4, 25.0%). Patients harbored nodules on the back (14, 87.5%), upper extremities (7, 43.8%), lower extremities (7, 43.8%), buttocks (5, 31.3%), and head or neck (3, 18.8%). Linear regression models revealed the presence of back lesions and predicted concomitant medical complications (ß = 2.71, p = 0.021). CONCLUSIONS: Patients undergoing surgical management for SCFN most commonly harbor lesions on the back and extremities that are secondary to therapeutic hypothermia or of unknown origin. Reporting of additional cases is needed to further elucidate surgical management and outcomes.

The impact of post-mastectomy radiation timing on overall outcomes of autologous free-flap breast reconstruction.

BACKGROUND: The optimal timing of post-mastectomy radiation therapy (PMRT) in autologous breast reconstruction is controversial. Our study compares overall reconstructive outcomes in patients who received post-mastectomy radiation therapy either before or after the autologous flap. METHODS: A single-center retrospective review was performed for patients who underwent free flap breast reconstruction and post-mastectomy radiation from January 2004 through January 2021. Demographic, intraoperative, and post-operative variables were recorded. RESULTS: A total of 452 free flaps were identified, and 82 underwent PMRT. 59.8% were radiated with an expander prior to free flap surgery (PreFlap), and 40.2% flaps underwent PMRT (PostFlap). PostFlap patients were significantly younger (43.0 vs. 47.9 years, p = .016). There were no significant differences in free flap outcomes between the two cohorts including thrombosis, venous congestion, flap loss, takebacks, fat necrosis, seroma, or infection. Mastectomy skin flap necrosis was significantly higher in the PostFlap cohort (9.1% vs. 0%, p = .032), but nipple necrosis rates did not differ. There were no significant differences in number or need for revision surgeries, fat necrosis, or fat grafting between groups. However, there were significantly more total reconstructive complications, including infection and wound breakdown, experienced by the PreFlap cohort (46.9% vs. 24.2%, p = .038). CONCLUSIONS: Timing of PMRT did not impact free flap outcomes, but those who had the expander radiated experienced significantly more complications overall. For the 34.7% of patients in the preFlap group who planned for autologous reconstruction form initial consultation, radiation after the flap may have improved their overall outcomes. As added complications cause delays in cancer therapy and final reconstruction, our results suggest that PMRT of the flap when possible may improve the overall experience for breast cancer patients.

Nodular cystic fat necrosis: a distinctive rare soft-tissue mass.

We report the case of a 34-year-old female who was evaluated for a right lower extremity soft-tissue mass, found to be a large cystic lesion bound by fibrous tissue containing innumerable, freely mobile nodules of fat. Her presentation suggested the diagnosis of nodular cystic fat necrosis (NCFN), a rare entity that likely represents a morphological subset of fat necrosis potentially caused by vascular insufficiency secondary to local trauma. Her lesion was best visualized using MRI, which revealed characteristic imaging features of NCFN including nodular lipid-signal foci that suppress on fat-saturated sequences, intralesional fluid with high signal intensity on T2-weighted imaging, and a contrast-enhancing outer capsule with low signal intensity on T1-weighted imaging. Ultrasound imaging offered the advantage of showing mobile hyperechogenic foci within the anechoic cystic structure, and the lesion was otherwise visualized on radiography as a nonspecific soft-tissue radiopacity. She was managed with complete surgical excision with pathologic evaluation demonstrating, similar to the radiologic features, innumerable free-floating, 1-5 mm, smooth, nearly uniform spherical nodules of mature fat with widespread necrosis contained within a thick fibrous pseudocapsule. Follow-up imaging revealed no evidence of remaining or recurrent disease on postoperative follow-up MRI. The differential diagnosis includes lipoma with fat necrosis, lipoma variant, atypical lipomatous tumor, and a Morel-Lavallée lesion. There is overlap in the imaging features between fat necrosis and both benign and malignant adipocytic tumors, occasionally making this distinction based solely on imaging findings challenging. To our knowledge, this is the largest example of NCFN ever reported.

Utilization of the internal mammary perforators as the recipient vessels for microsurgical breast reconstruction: A systematic review and meta-analysis of the literature.

BACKGROUND: The selection of reliable recipient vessels is essential for successful free tissue transfer. The use of internal mammary intercostal perforators (IMAPs), instead of the internal mammary vessels as the recipient vessels, has been described in breast reconstruction. Debates exist regarding the reliability of these perforators as recipient vessels because of their variability in location and caliber. The aim of this paper was to conduct a systematic literature review and meta-analysis to determine the reliability of the IMAPs as recipient vessels. METHODS: A systematic literature review was performed on the "PubMed," "Medline," "Ovid," and "Cochrane library" databases for articles published from January 1990 to March 2021. Exclusion criteria were non-English studies, reports with case number less than 5, cadaveric or animal studies, and studies with incomplete postoperative outcomes. The reliability of using IMAPs for breast reconstruction was determined by assessing the reported rates of partial or complete flap failure and other complications (fat necrosis, skin necrosis, and requirement for revision surgery). RESULTS: Three hundred and sixteen cases in 13 studies were included for further analysis with more than 85% of the IMAPs suitable for anastomosis being located in the second and third intercostal spaces. Partial or total flap failure was reported in three of 316 patients (0.95%). The rate of other complications such as fat necrosis, skin necrosis, and requirement for revision surgery were all less than 5%. CONCLUSION: With deliberate preoperative planning, delicate perioperative manipulation, and meticulous microvascular anastomosis, the internal mammary perforators can be used as reliable recipient vessels in microvascular breast reconstruction.

Autologous Fat Grafting in Breast Augmentation: A Systematic Review Highlighting the Need for Clinical Caution.

BACKGROUND: Autologous fat grafting (AFG) is a breast augmentation method for treating volume and contour abnormalities. This systematic review aims to summarize complications, radiologic safety, volume retention, and patient satisfaction associated with AFG. METHODS: The PubMed, Embase, Google Scholar, Cochrane Central Register of Controlled Trials, Wiley library, clinical key/Elsevier, and EBSCO databases were searched for relevant studies from January of 2009 to March of 2022. Articles describing AFG for breast augmentation were selected based on predetermined inclusion and exclusion criteria. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were adhered to, and the study was registered on the International Prospective Register of Systematic Reviews. The Risk of Bias in Nonrandomized Studies of Interventions assessment was used to assess the quality of studies and the risk of bias was measured using the Cochrane Risk of Bias Assessment Tool for Nonrandomized Studies of Interventions. RESULTS: A total of 35 studies comprising 3757 women were included. The average follow-up duration was 24.5 months (range, 1 to 372 months). The overall complication rate was 27.8%, with fat necrosis making up 43.7% of all complications. Average fat volume injected was 300 mL (range, 134 to 610 mL), and average volume retention was 58% (range, 44% to 83%). Volume retention was greater with supplementation of fat with platelet-rich plasma and stromal vascular fraction. The most common radiologic changes were fat necrosis (9.4%) and calcification (1.2%). After 1 year of follow-up, patient satisfaction was, on average, 92% (range, 83.2% to 97.5%). The included studies were of good quality and consisted of a moderate risk of bias. CONCLUSIONS: AFG was associated with an overall complication rate of 27.8%. Additional supplementation of fat with platelet-rich plasma and stromal vascular fraction may improve graft survival. Despite poor volume retention being a persistent drawback, patient satisfaction remains high.

Electrochemical Lipolysis Induces Adipocyte Death and Fat Necrosis: In Vivo Pilot Study in Pigs.

BACKGROUND: Current minimally invasive fat reduction modalities use equipment that can cost thousands of U.S. dollars. Electrochemical lipolysis (ECLL), using low-cost battery and electrodes (approximately $10), creates acid/base within fat (width, approximately 3 mm), damaging adipocytes. Longitudinal effects of ECLL have not been studied. In this pilot study, the authors hypothesize that in vivo ECLL induces fat necrosis, decreases adipocyte number/viability, and forms lipid droplets. METHODS: Two female Yorkshire pigs (50 to 60 kg) received ECLL. In pig 1, 10 sites received ECLL, and 10 sites were untreated. In pig 2, 12 sites received ECLL and 12 sites were untreated. For ECLL, two electrodes were inserted into dorsal subcutaneous fat and direct current was applied for 5 minutes. Adverse effects of excessive pain, bleeding, infection, and agitation were monitored. Histology, live-dead (calcein, Hoechst, ethidium homodimer-1), and morphology (Bodipy and Hoechst) assays were performed on day 0 and postprocedure days 1, 2, 7, 14 (pig 1 and pig 2), and 28 (pig 2). Average particle area, fluorescence signal areas, and adipocytes and lipid droplet numbers were compared. RESULTS: No adverse effects occurred. Live-dead assays showed adipocyte death on the anode on days 0 to 7 and the cathode on days 1 to 2 (not significant). Bodipy showed significant adipocyte loss at all sites ( P < 0.001) and lipid droplet formation at the cathode site on day 2 ( P = 0.0046). Histology revealed fat necrosis with significant increases in average particle area at the anode and cathode sites by day 14 (+277.3% change compared with untreated, P < 0.0001; +143.4%, P < 0.0001) and day 28 (+498.6%, P < 0.0001; +354.5%, P < 0.0001). CONCLUSIONS: In vivo ECLL induces fat necrosis in pigs. Further studies are needed to evaluate volumetric fat reduction. CLINICAL RELEVANCE STATEMENT: In vivo ECLL induces adipocyte death and fat necrosis. ECLL has the potential to be utilized in body fat contouring.

Surgical management of breast fat necrosis: Multi-institutional data analysis of early outcomes and risk factors for complications.

BACKGROUND: Breast fat necrosis (BFN) is a non-cancerous condition affecting the adipose tissue. Despite incidence rates of up to 25% after breast surgery, little is known about risk factors and postoperative outcomes following the surgical treatment of BFN. METHODS: The National Surgical Quality Improvement Program of the American College of Surgeons (2008-2021) was queried to identify female patients diagnosed with and surgically treated for BFN. Outcomes of interest included 30-day surgical and medical complications, reoperation, and readmission. We performed confounder-adjusted multivariable analyses to determine risk factors. RESULTS: The study population included 1179 female patients (mean age: 55.8 ± 13.8 years), of whom 96% (n = 1130) underwent direct excision and 4.2% (n = 49) received debridement of necrotic tissue. The majority of cases were operated on by general surgeons (n = 867; 74%) in the outpatient setting (n = 1107; 94%). Overall, 74 patients (6.3%) experienced postoperative adverse events, most of which were surgical complications (n = 43; 3.7%). Twenty-one (1.8%) women had to return to operating room, while readmission was reported in 18 (1.5%) cases. Adverse events were significantly more likely to occur in patients with chronic heart failure (p = 0.002) and higher wound classes (p = 0.033). CONCLUSION: Complication rates following the surgical management of BFN were found to be relatively high and seen to correlate with the setting. We identified chronic heart failure and wound contamination as risk factors for complication occurrence. These evidence-based insights may sensitize surgeons to critically balance patients' eligibility for BFN surgery and refine perioperative algorithms.

An Updated Systematic Review and Meta-Analysis of Tissue Oximetry Versus Conventional Methods for Postoperative Monitoring of Autologous Breast Reconstruction.

BACKGROUND: Tissue oximetry monitoring has shown superior outcomes to conventional monitoring methods for autologous breast reconstruction in retrospective studies with consecutive cohorts. A recent study used consecutive cohorts with tissue oximetry as the earlier cohort and found that tissue oximetry was nonsuperior. We hypothesize that improvement in microsurgical outcomes with institutional experience confounds the superiority of tissue oximetry demonstrated in prior studies. This study aimed to perform a systematic review and meta-analysis of the outcomes of tissue oximetry monitoring compared with conventional monitoring. METHODS: Relevant studies were found using PubMed, Embase, and Web of Science searches for keywords such as near-infrared spectroscopy or tissue oximetry and microsurgery. Studies included compared tissue oximetry and conventional monitoring in autologous breast reconstruction patients. Studies were excluded if they did not contain a comparison group. Random-effective models were used to analyze early returns to the operating room, the total number of partial or complete flap loss, and late fat necrosis. RESULTS: Six hundred sixty-nine studies were identified; 3 retrospective cohort studies met the inclusion criteria. A total of 1644 flaps were in the tissue oximetry cohort, and 1387 flaps were in the control cohort. One study contained tissue oximetry as the former cohort; 2 had tissue oximetry as the latter. Neither technique was superior for any measured outcomes. The estimated mean differences between tissue oximetry and conventional monitoring method were early returns, -0.06 (95% confidence interval [CI], -0.52 to 0.410; P = 0.82); partial flap loss, -0.04 (95% CI, -0.86 to 0.79; P = 0.93); complete flap loss, -1.29 (95% CI, -3.45 to 0.87; P = 0.24); and late fat necrosis -0.02 (95% CI, -0.42 to, 0.39; P = 0.94). CONCLUSIONS: In a systematic review and meta-analysis of mixed timeline retrospective cohort studies, tissue oximetry does not provide superior patient outcomes and shifts our current understanding of postoperative breast reconstruction monitoring. Prospective studies and randomized trials comparing monitoring methods need to be included in the existing literature.

The effects of breast reduction with superomedial and inferior pedicle techniques on radiological breast imaging.

BACKGROUND: Several breast reduction techniques have been introduced, and the reliability of these techniques has been demonstrated in clinical practice. However, it is still controversial how patients should be evaluated radiologically both preoperative and postoperative. This study aims to compare the radiological findings seen following reduction mammoplasty with two different techniques (inferior pedicle and superomedial pedicle), in connection with the surgical steps. METHODS: Medical records of 141 patients and a total of 278 breasts who underwent breast reduction with the diagnosis of macromastia were retrospectively analyzed. Demographic and operative data such as age, type of pedicle, preoperative and postoperative nipple-areola complex (NAC) position, and NAC transfer distance were recorded. Radiological evaluation was performed by two radiologists experienced in breast imaging by reinterpreting preoperative and postoperative mammography images. RESULTS: The rate of postoperative structural distortion (p < 0.001), thickened areola (p = 0.011), and retroareolar fibrotic band (p < 0.001) were observed to be significantly higher in the superomedial group. The risk of fat necrosis increases as the NAC transfer distance increases and a value of >9.5 cm in the NAC transfer distance can be considered as the cutoff value in terms of fat necrosis development, especially in those using superomedial pedicle technique. CONCLUSION: Surgical technique-specific benign radiological changes occur following reduction mammoplasty. However, these changes do not significantly affect the Breast imaging, reporting, and data system category. The localization of fat necrosis differs depending on the surgical technique, and the risk of fat necrosis increases as the NAC transfer distance increases, especially in those who have undergone superomedial pedicle breast reduction surgery.

Pancreatitis, panniculitis and polyarthritis (PPP) syndrome.

A young male presented with intermittent high-grade fever, asymmetric polyarthritis and erythematous, tender nodules over left shin for 2 months duration. He had a history of alcohol dependence with multiple episodes of acute pancreatitis. With polyarthritis progressing relentlessly, unresponsive to non-steroidal anti-inflammatory drugs and steroids, a provisional diagnosis of sarcoidosis was considered. Indeed, he was treated with azathioprine and rituximab with no effect. Biopsy of the skin nodule revealed subcutaneous fat necrosis, foam cells, deposition of eosinophilic amorphous material and calcification. Synovial fluid aspiration from the arthritic knee obtained purulent but surprisingly culture-negative material, rich in triglycerides. Abdominal CT confirmed chronic pancreatitis. Final diagnosis of pancreatitis, panniculitis and polyarthritis (PPP) syndrome was made. He underwent surgical pancreatic ductal drainage leading to complete remission of symptoms. PPP syndrome triad occurs due to leakage of pancreatic enzymes into systemic circulation and subsequent fat necrosis. Surgical drainage of pancreatic duct is often curative.

Case report on the radiographic features of epipericardial fat necrosis in a patient presenting with acute chest pain.

Epipericardial fat necrosis (EFN) is a rare and benign condition. The three cardinal features of EFN are acute pleuritic chest pain, radiological features of an encapsulated fatty lesion within the epipericardial fat and the presence of inflammation within the surrounding pericardium. The exact aetiology is still unknown, and there are no known risk factors. The condition appears to be a transient process with no associated long-term complications. In this case study, we demonstrate the multitude of radiological features associated with this condition. A 29-year-old Caucasian female presented with acute pleuritic chest pain. There were no acute changes on her blood work, electrocardiogram (ECG) or echocardiogram. The chest radiograph showed an opacity projected within the anterior mediastinum. Further imaging, with computed tomography (CT) chest with contrast, was performed to define the characteristics of the opacity. This confirmed an encapsulated, mixed fat, soft tissue density in the left pericardiac region deemed to represent EFN. Follow-up magnetic resonance (MR) cardiac imaging at 1, 4 and 12 months demonstrated the self-resolving characteristics of this condition. EFN is a rare differential diagnosis to consider in patients presenting with acute pleuritic chest pain when laboratory tests are normal and there are no acute ECG findings. EFN should be excluded by imaging with CT or MRI of the heart. We have demonstrated through follow-up MR imaging the progression and resolution of EFN over 12 months.

Stem Cell Enriched Fat Grafts versus Autologous Fat Grafts in Reconstructive Surgery: Systematic Review and Meta-Analysis.

OBJECTIVE: To compare the outcomes of stem cell-enrichment fat grafting (SCEFG) versus autologous fat grafting (AFG) for reconstructive purposes. METHODS: A systematic review and meta-analysis was performed as per the preferred reporting items for systematic reviews and meta-analyses. Guidelines and a search of electronic information was conducted to identify all Randomised Controlled Trials (RCTs), case-control studies and cohort studies comparing the outcomes of SCEFG versus AFG. Volume retention, fat necrosis, cancer recurrence, redness and swelling, infection, and cysts were primary outcome measures. Secondary outcome measures included patient satisfaction post-surgery, scar assessment, operation time and number of fat grafting sessions. Fixed and random effects modelling were used for the analysis. RESULTS: 16 studies enrolling 686 subjects were selected. Significant differences between the SCEFG and AFG groups were seen in mean volume retention (standardised mean difference = 3.00, P < 0.0001) and the incidence of redness and swelling (Odds Ratio [OR] = 441, P = 0.003). No significant difference between the two groups in terms of fat necrosis (OR = 2.23, P = 0.26), cancer recurrence (OR = 1.39, P = 0.58), infection (OR = 0.30, P = 0.48) and cysts (OR = 0.88, P = 0.91). For secondary outcomes, both cohorts had similar results in patient satisfaction, scar assessment and number of fat grafting sessions. Operation time was longer for the intervention group. CONCLUSIONS: SCEFG offers better outcomes when compared to AFG for reconstructive surgery as it improves the mean volume retention and does not worsen patient satisfaction and surgical complications except for self-limiting redness and swelling. Further clinical trials are recommended to support this argument and validate the use of SCEFG in clinical practice. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Epipericardial fat necrosis in chest CT and MRI: a case report of an unusual cause of chest pain associated with the initial diagnosis of undifferentiated connective tissue disease.

BACKGROUND: Epipericardial fat necrosis (EFN) is a benign and self-limited condition of unknown cause with a good prognosis, usually affecting otherwise healthy patients. Clinically, it presents with severe acute left pleuritic chest pain, often leading the patient to the Emergency Room (ER). CASE PRESENTATION: A 23-year-old male, smoker (5 pack-years), was evaluated in the ER due to left pleuritic chest pain, worsening with deep breathing and Valsalva maneuver. It was not associated with trauma and did not present other symptoms. The physical examination was unremarkable. The arterial blood gases while breathing room air and the laboratory tests, including D-dimers and high-sensitivity cardiac Troponin T, were normal. The chest radiograph, electrocardiogram, and transthoracic echocardiogram showed no abnormalities. A computed tomography (CT) pulmonary angiogram showed no signs of pulmonary embolism but depicted at the left cardiophrenic angle a focal 3 cm ovoid-shaped fat lesion with stranding and thin soft tissue margins, consistent with necrosis of the epicardial fat, which was confirmed by magnetic resonance (MRI) of the chest. The patient was medicated with ibuprofen and pantoprazole, with clinical improvement in four weeks. At a two-month follow-up, he was asymptomatic and presented radiologic resolution of the inflammatory changes of the epicardial fat of the left cardiophrenic angle on chest CT. Laboratory tests revealed positive antinuclear antibodies, positive anti-RNP antibody, and positive lupus anticoagulant. The patient complained of biphasic Raynaud's phenomenon initiated five years ago, and a diagnosis of undifferentiated connective tissue disease (UCTD) was made. CONCLUSIONS: This case report highlights the diagnosis of EFN as a rare and frequently unknown clinical condition, which should be considered in the differential diagnosis of acute chest pain. It can mimic emergent conditions such as pulmonary embolism, acute coronary syndrome, or acute pericarditis. The diagnosis is confirmed by CT of the thorax or MRI. The treatment is supportive and usually includes non-steroidal anti-inflammatory drugs. The association of EFN with UCTD has not been previously described in the medical literature.

Epipericardial fat necrosis as a differential diagnosis of acute chest pain: a case report and algorithm proposal for diagnostic approach.

Chest pain is a frequent, potentially life-threatening condition in the emergency department and requires immediate investigation and treatment. This case report highlights a rare differential diagnosis of pleuritic chest pain: epipericardial fat necrosis. A 29-year-old man presented with normal clinical evaluation, electrocardiography, point-of-care ultrasound, and unremarkable laboratory tests. The initial hypothesis was acute pleuritis. Chest radiography revealed peri-cardiac nonspecific findings, and computed tomography revealed epicardial fat necrosis. Despite the rarity of this condition, accurate diagnosis allows for better practices. An algorithm for a diagnostic approach is proposed.