Acellular dermal matrix (ADM) is an immunologically inert graft, typically from cadaveric skin, often used in postmastectomy breast reconstruction. Created from decellularized dermal tissues that have been treated to remove DNA and antigenic donor cells (leaving extracellular matrix), ADM is often used as a structural scaffold or sling to reinforce and support the structure and position of a breast implant during postoperative integration in implant-based breast reconstruction; ADM can also be used to fill cosmetic defects. Advantages of ADM use include improved cosmesis and reduced capsular contracture rates. On US, ADM can be seen as a subtle band with variable echogenicity adjacent to the implant. When folded on itself or redundant, ADM may present as a palpable oval mass with indistinct or circumscribed margins and variable echogenicity. On mammography, ADM can be seen as a circumscribed oval equal density mass when redundant and folded on itself; a layered appearance may be evident on tomosynthesis. On MRI, presence and absence of enhancement have been documented. Imaging findings likely vary depending on the degree of host tissue remodeling and incorporation, and when biopsied, histopathologically, ADM may be difficult to distinguish from scarring. Successful imaging diagnosis of ADM is aided by clinical knowledge of the intraoperative use and configuration of ADM, which may help differentiate ADM from new or recurrent malignancy and avoid unnecessary biopsy.

暂无摘要。

UNASSIGNED: Abdominal fat necrosis is mostly an incidental finding during rectal examination manifested by the presence of hard necrotic masses of different sizes. Differential diagnosis includes gastrointestinal neoplasia, abdominal abscessation and mummified fetuses. This report describes the clinical, hematological, biochemical, sonographic, and pathologic findings in a female Arabian camel (Camelus dromedaries) with abdominal fat necrosis.
UNASSIGNED: A 7-year-old female dromedary camel was presented for examination because of weakness and progressive weight loss since months ago. Anthelmintics, analgesics, broad-spectrum antimicrobials, anti-inflammatories and stomachics were administered, but did not result in significant improvement. Preliminary examination of the case revealed emaciation with a body condition score of 2.5 (scale 1-5). The cardiopulmonary, digestive, and urinary systems were evaluated transcutaneously by sonography in the recumbent position. Multiple echogenic masses-located within the intestinal loops were observed alongside few hypoechogenic masses. A hyperechogenic peritoneal effusion and enlarged mesenteric lymph nodes were also detected. Decreased hematocrit value, normocytic normochromic anemia, neutrophilic leukocytosis, hypoalbuminemia, hhyperglobulinemia, hyperglycemia, hyponatremia, and hyperkalemia were detected. A free-hand, ultrasound-guided biopsy was examined histopathologically and revealed multiple abdominal fat necrosis, severe fibrosis, and pancreatitis.
UNASSIGNED: It is concluded that, transabdominal ultrasonography in camels was valuable for suspicious of abdominal mesenteric masses and helpful in sampling of a representative biopsy specimen However, histological examination of the biopsy remains the final diagnostic method.

Intraperitoneal focal fat infarction (IFFI) is a rare condition characterized by infarction of fatty tissue within the abdominal cavity. Lesser omental infarction, a relatively rare type of IFFI, occurs when there is an infarction of fat within the lesser omentum. Patients typically present with acute abdominal pain that can mimic more serious conditions. This case report highlights the clinical presentation, diagnostic challenges, and management strategies for patients presenting to the emergency department with lesser omental infarction. A 63-year-old female presented to the emergency department with a chief complaint of epigastric abdominal pain that had been persisting for approximately a week and a half. The pain, which initially seemed like a sore muscle, became increasingly sharp and intermittent, with tenderness upon palpation of the epigastric area. Computed tomography (CT) imaging revealed an omental infarct in the lesser sac with focal inflammation in the fat of the lesser omentum. Through conservative management with analgesics and anti-inflammatory medication, the patient experienced resolution of her symptoms within a few days and had a follow-up with the gastrointestinal team several weeks later. Lesser omental infarction typically results from compromised blood flow due to torsion or thrombosis, leading to ischemia and necrosis of the fatty tissue. CT imaging is crucial for its diagnosis and reveals fat-density lesions with surrounding inflammatory changes. Conservative management is typically effective, though in rare cases, surgical intervention may be necessary when significant vital signs and electrolyte derangements occur.

\"Cysts of the ligamentum flavum (cysts-LF)\" is the term for non-neoplastic cystic lesion involving LF. The aim of the present study was to elucidate the histopathological characteristics and pathogenesis of \"cysts-LF\". Herein, we defined cysts-LF as spinal cysts containing degenerative LF components. From archival cases, we investigated 18 symptomatic cysts-LF surgically removed from 18 patients (13 males and five females; median age 68.5 years [range, 42-86 years]). The elastic fibers of LF components in the wall were separated and/or torn, and cyst walls were accompanied by chondroid metaplasia (17 cases), myxoid changes (13 cases), ossification (11 cases), amyloid deposits (14 cases), hemosiderosis (six cases), granular/smudgy calcification (four cases), synovial cell linings (three cases), and severe inflammatory infiltrates (one case). These histologic features of our cysts-LF were shared by previously reported \"cysts-LF.\" Fourteen cysts-LF demonstrated vascular stenosis/occlusion, and eight showed thick hyalinized vessels, suggesting local circulatory insufficiency. Eight cases (44%) exhibited lipomembranous fat necrosis, accompanied by hyalinized vascular changes (p = 0.003). Ischemic conditions were observed in nearly half of the present cysts-LF, and may be one of the main contributing factors for the formation of cysts-LF, via degeneration and cystic changes in the LF.

OBJECTIVE: To describe the morphologic sonographic appearances and frequency of the \"halo sign\" in the setting of fat necrosis on shear wave elastography (SWE).
METHODS: Patients with clinically suspected fat necrosis were prospectively scanned using SWE in addition to standard gray-scale and Doppler images. Cases were qualitatively grouped into one of three sonographic appearances: focal hypoechoic lesion with increased internal tissue stiffness (\"focal stiffness\"), focal hypoechoic lesion with isoechoic or hyperechoic periphery demonstrating increased tissue stiffness relative to the central hypoechoic lesion (\"halo stiffness\"), heterogeneously echogenic lesion with diffusely increased stiffness (\"heterogeneous stiffness\").
RESULTS: Exactly 19 patients met inclusion criteria (female n = 14; male n = 5). Shear wave velocities were recorded and retrospectively evaluated. The mean clinical follow-up was 11.4 months (range 3.0-25.5). Lesions demonstrated higher average tissue stiffness than background tissue (overall mass shear wave velocity 3.26 m/s, background 1.42 m/s, P < .001; lesion Young\'s modulus 40.85 kPa vs background 7.22 kPa, P < .001). The halo sign was identified in 10/19 (55%) patients.
CONCLUSIONS: The halo sign is a potentially useful sign in the setting of fat necrosis seen in the majority of clinically suspected cases.

Melanized focal changes (MFCs) in the fillet of farmed Atlantic salmon is a major quality concern. The changes are thought to initially appear as acute red focal changes (RFCs) that progress into chronic MFCs. Recent findings have indicated that hypoxia may be important in their development, possibly leading to necrosis affecting not only myocytes but also adipocytes. Thus, the aim of this study was to investigate possible hypoxic conditions in RFCs and the subsequent inflammatory responses and lesions in the adipose tissue in RFCs and MFCs. A collection of RFCs, MFCs and control muscle samples from several groups of farmed salmon was studied. Using immunohistochemistry, we found induction of the hypoxia-inducible factor 1 pathway in RFCs. Histological investigations of RFCs and MFCs revealed different stages of fat necrosis, including necrotic adipocytes, a myospherulosis-like reaction and the formation of pseudocystic spaces. Accumulations of foamy macrophages were detected in MFCs, indicating degradation and phagocytosis of lipids. Using in situ hybridization, we showed the presence of tyrosinase- and tyrosinase-related protein-1-expressing amelanotic cells in RFCs, which in turn became melanized in MFCs. In conclusion, we propose a sequence of events leading to the formation of MFCs, highlighting the pivotal role of adiposity, hypoxia and fat necrosis.

A patient on long-term glucocorticoid therapy for peristomal pyoderma gangrenosum (PPG) who developed mucormycosis (MM) of the wound with dissemination was presented. The importance of skin biopsy, together with clinical evaluation in patients with PPG who are resistant to conventional therapy or who develop new symptoms related to their PPG is stressed. The risk and pathogenesis of invasive fungal infections with long-term corticosteroid therapy were explored. The epidemiology and detection of mucormycosis is discussed in this article.

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.
OBJECTIVE: 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.
METHODS:

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.