Liposuction Treatment of a Subacute Morel-Lavallée Lesion: A Case Report.

INTRODUCTION: A Morel-Lavallée lesion (MLL) is a rare and aesthetically concerning condition caused by a shearing force between subcutaneous fat and underlying fascia. Subsequent seroma formation occurs after the initial trauma of a crush injury, ligamentous sprain, or abdominal liposuction. Misdiagnosed lesions lead to inadequate treatment and are a source of chronic pain. CASE REPORT: The case of a 33-year-old woman who presented with a large, painful subacute MLL of the left thigh after being run over by a truck 3 weeks prior is reported. Physical examination revealed severe hyperesthesia and fluctuance of the left thigh. After confirmation of the fluid collection by X-ray and computed tomography angiogram, the authors performed liposuction of the cavity and seroma wall to evacuate and treat the lesion. Postoperative care consisted of a temporary drain, thigh compression, and oral antibiotics. Immediate reduction in size was appreciated intraoperatively with no reaccumulation of fluid at postoperative visits on week 1 and week 6. The pathology report confirmed seroma etiology, and all cultures of the fluid returned negative. At the end of her postoperative course, the patient reported a reduction in pain and no recurrence of her symptoms. CONCLUSIONS: This case of MLL was diagnosed early and successfully treated with liposuction, resulting in an acceptable cosmetic outcome. It is the authors' hope that this case report will lead to earlier diagnosis and proper treatment of MLLs.

Painful Traumatic Neuromas in Subcutaneous Fat: Visibility and Morphologic Features With Ultrasound.

OBJECTIVES: Subcutaneous neuromas usually result from trauma and may lead to dissatisfaction in patients with a trigger point, loss of sensitivity in the relevant territory of innervation, and spontaneous neuropathic pain. Confirming clinically suspected cases of neuroma may prove difficult. The objective of this study was to evaluate the visibility and morphologic features of traumatic subcutaneous neuromas of the limbs with ultrasound (US). METHODS: Between January 2012 and August 2016, 38 consecutive patients clinically suspected of having subcutaneous neuromas were investigated with US. The diagnosis was confirmed on the basis of a focal morphologic abnormality of the nerve associated with trigger pain. Each neuroma was classified into 1 of 3 subtypes based on its injury pattern. The subtypes were terminal neuroma, spindle neuroma, and scar encasement, either isolated or associated with these subtypes. RESULTS: Forty-four lesions were found in the 38 patients, including 29 spindle neuromas (65.9%), 14 terminal neuromas (31.8%) and 1 scar encasement with no nerve caliber abnormality (2.3%). Fifteen neuromas (35% of all neuromas) were associated with scar encasement. In 13 cases that required surgery, the diagnosis of neuroma or scar encasement could be surgically proven and confirmed the validity of the US findings. CONCLUSIONS: Ultrasound can be used to show and classify subcutaneous nerves of the upper and lower limbs with high accuracy. The US trigger sign provides an indication of neuroma involvement in pain. This modality can play a substantial role both in the preoperative planning of neuroma surgery and in therapeutic US-guided procedures.

Lipoatrofia por inyección de esteroides - Diagnóstico y tratamiento / Lipoatrophy by injection of steroids - Diagnosis and treatment

Existen diferentes opciones para el tratamiento de la lipoatrofi a secundaria a la inyección local de esteroides. Presentamos las diferentes alternativas de tratamiento y sus resultados sobre cuatro pacientes con diferente grado de lesión y en diferentes áreas corporales.

There are diff erent options for the treatment of lipoatrophy secondary to the local injection of steroids. We present the diff erent treatment alternatives and their results on four patients with diff erent degrees of injury and in diff erent body areas.

Fluid signal changes around the knee on MRI are associated with increased volumes of subcutaneous fat: a case-control study.

BACKGROUND: Fluid in the subcutaneous fat is a common finding anterior to the knee on MRI. This may be caused by chronic low-grade shearing injuries in patients who are overweight. The purpose of this study was to determine if there is a difference in the amount of subcutaneous fat around the knee between patients with these appearances and controls. METHODS: This was a retrospective case-control study. Following a sample size calculation on pilot data, eighteen sequential patients demonstrating hyper-intense subcutaneous signal changes around the knee on fat-saturated T2-weighted MRI were identified from PACS (18 females, mean age 45, range 31-62). Age and gender-matched patients without abnormal T2 MR signal changes were selected. Two observers independently drew regions of interest representing cross-sectional areas of bone and fat. The location of T2 signal hyper-intense lesions was characterized by consensus. RESULTS: Inter and intra-rater intraclass reproducibility was "excellent" (ICC > 0.8). The mean cross-sectional area of bone for patients with T2 hyper-intense lesions was 31.79cm2 (SD 2.57) and for controls 30.11cm2 (SD 3.20) which was not significantly different (p = 0.09). The median cross-sectional area of fat for the study group was 62.29cm2 (IQR 57.1-66.5) and for controls was 32.77cm2 (IQR 24.8-32.3) which was significantly different (p < 0.0001). Consensus agreement demonstrated all T2 hyper-intense lesions were anterior to the knee extensor mechanism. CONCLUSION: Subcutaneous fluid around the knee is associated with an increased amount of subcutaneous fat, anterior to the knee extensor mechanism. This may be caused by shearing injuries in fat with reduced elasticity associated with metabolic syndrome.

Imaging of traumatic injury and impingement of anterior knee fat.

Fat is not just used by the body as bulk tissue. In addition to its role in storing energy and regulating hormone action, fat is used in some parts of the body for its mechanical properties. The anatomy of anterior knee fat is more complex than it appears at first sight and is capable of withstanding considerable compressive and shear stress. Specific lesions occur when such mechanical stress exceeds the physiological limits and are yet little known. Superficial fat can be the site of either acute injury by closed degloving called the Morel-Lavallée lesion or chronic injury, when subject to repeat excessive shear forces, due to more complex and less well-defined disruptions that result in pseudo-bursitis. There are three main anterior, intracapsular and extrasynovial fat pads in the knee joint, which are the infrapatellar fat pad (IFP) or Hoffa's fat pad, the quadriceps fat pad and the prefemoral fat pad. The IFP plays an important role as a mechanical shock absorber and guides the patella tendon and even the patella itself during flexion-extension movements. In response to repeated excessive stress, an inflammatory reaction and swelling of the IFP is first observed, followed by a fibrotic reaction with metaplastic transformation into fibrous, cartilaginous or bone tissue. More rarely, the two other deep fat pads (quadriceps and prefemoral) can, if subject to repeated stress, undergo similar restructuring inflammatory reactions with metaplasia resulting in tissue hardening, anterior pain and partial loss of function.

Morphological Changes in Subcutaneous White Adipose Tissue After Severe Burn Injury.

Severe burn injury produces a plethora of metabolic abnormalities which contribute to the prolonged morbidity of burn survivors. The authors have recently demonstrated trans-differentiation of white adipose tissue (WAT) after burn trauma, toward a more thermogenic phenotype. However, the impact of burn injury on subcutaneous WAT (sWAT) morphology in humans is unknown. Here, the authors studied the effect of severe burn injury on the architecture of sWAT. sWAT was collected from 11 severely burned children (11 ± 3 years; 55 ± 16% total BSA burned) and 12 nonburned healthy children (9 ± 3 years). Histology, electron microscopy, immunohistochemistry, and immunofluorescence were performed on fixed adipose tissue sections. sWAT cytokine and collagen concentrations were measured by multiplex assay and sirius/fast green staining method, respectively. sWAT histology demonstrated multiple fat droplets, significantly (P < .05) reduced mean cell size (104 ± 6 vs 68 ± 3 µm) and higher collagen content (7 ± 0.8 vs 4 ± 0.4) in burn patients. sWAT from burn victims stained positive for CD68 suggesting infiltration of macrophages. Furthermore, electron microscopic analysis showed multiple fat droplets and greater mitochondrial abundance in sWAT of burn survivors. In agreement with this, mitochondrial respiratory capacity in the leak and coupled state increased by 100% in sWAT of burned children from 1 to 3 weeks postinjury. The cytokines IL-6, IL-8, IL-13, IL-1a, IL-1b, MCP-1, and TNF-α were all significantly greater in the sWAT of burned children versus healthy children (P < .05). Furthermore, IL-6, IL-8, IL1-a, IL-1b, and TNF-α significantly increased after injury in sWAT of burned children (P < .05). This study provides detailed evidence of morphological and functional changes in sWAT of burn survivors which was associated with tissue inflammation. A better understanding of morphological and functional changes in sWAT will help discern the mechanisms underlying hypermetabolism in burned patients.

Intramuscular risk at insulin injection sites--measurement of the distance from skin to muscle and rationale for shorter-length needles for subcutaneous insulin therapy.

BACKGROUND: Intramuscular (IM) injection can increase insulin absorption, causing hypoglycemia. Available needle lengths today are 4-12.7 mm for pens and 6-12.7 mm for syringes. We describe the distance (D) from skin surface to muscle fascia at injection sites for subcutaneous (SC) insulin therapy and recommend needle lengths to reduce IM injection risk. MATERIALS AND METHODS: At two locations in the United States, skin and SC fat thicknesses were measured by ultrasound at the abdomen, arm, thigh, and buttock in diverse adults (body mass index [BMI] range, approximately 19-65 kg/m²) with diabetes (n=341 with one or more paired skin and SC measurement, permitting calculation of D). The natural log of D by body site, BMI, and gender were analyzed using a mixed model to estimate IM risk. RESULTS: D varied significantly by body site, BMI, and gender (each P<0.001), increasing with higher BMI and in women. Median D ranged from 10.9 mm (95% confidence interval, 10.3, 11.6) at the thigh to 16.9 mm (15.9, 18.1) at the buttock. Minimum D was <3 mm at the thigh and <5 mm elsewhere. When inserted 90° without pinch-up, the most commonly used needle worldwide (8 mm) has estimated IM risks of 25% and 9.7%, respectively, in the thigh and abdomen, versus 1.6% and 0.1%, respectively, with a 4 mm needle. A 45° insertion reduces, but does not eliminate, IM risk with longer needles. CONCLUSIONS: Gender, BMI, and body site affect D; when combined with needle length and insertion angle, these factors permit detailed estimates of IM insulin injection risk. Such risk varies across sites, appears greatest at the thigh, is unnecessarily increased with 8 mm and 12.7 mm needles, and is greatly reduced with shorter-length needles and good injection technique.

Panniculitides, an algorithmic approach.

The issue of inflammatory diseases of subcutis and its mimicries is generally considered a difficult field of dermatopathology. Yet, in my experience, with appropriate biopsies and good clinicopathological correlation, a specific diagnosis of panniculitides can usually be made. Thereby, knowledge about some basic anatomic and pathological issues is essential. Anatomy differentiates within the panniculus between the fatty lobules separated by fibrous septa. Pathologically, inflammation of panniculus is defined and recognized by an inflammatory process which leads to tissue damage and necrosis. Several types of fat necrosis are observed: xanthomatized macrophages in lipophagic necrosis; granular fat necrosis and fat micropseudocysts in liquefactive fat necrosis; mummified adipocytes in "hyalinizing" fat necrosis with/without saponification and/or calcification; and lipomembranous membranes in membranous fat necrosis. In an algorithmic approach the recognition of an inflammatory process recognized by features as elaborated above is best followed in three steps: recognition of pattern, second of subpattern, and finally of presence and composition of inflammatory cells. Pattern differentiates a mostly septal or mostly lobular distribution at scanning magnification. In the subpattern category one looks for the presence or absence of vasculitis, and, if this is the case, the size and the nature of the involved blood vessel: arterioles and small arteries or veins; capillaries or postcapillary venules. The third step will be to identify the nature of the cells present in the inflammatory infiltrate and, finally, to look for additional histopathologic features that allow for a specific final diagnosis in the language of clinical dermatology of disease involving the subcutaneous fat.

Post-surgical lipophagic panniculitis: a specific model of traumatic panniculitis and new histopathological findings.

Aim of this work was to define the histopathological features of post-surgical panniculitis. Dermal and hypodermal changes will be analyzed in detail, to understand the cascade of events that characterize the tissue response to surgical trauma. Cutaneous re-excision specimens of cases of basal cell carcinoma, squamous cell carcinoma, and melanoma consecutively seen from January 1, 2011 to June 30, 2011 at the Department of Dermatology, University of Pavia, were included in this study. Only the cases in which the first surgical procedure included the subcutaneous fat, were considered. In addition, the time elapsed from the first surgical procedure and the re-excision had to be included in a period of time from one to three months. All the specimens were stained with hematoxylin and eosin. Thirty cutaneous re-excision specimens were studied. Histopathologic examination revealed changes of epidermis, ranging from slight atrophy to moderate hyperplasia. In two cases focal ulceration was seen, with transfollicular elimination of foreign body material. The main dermal changes observed were the: 1) scar with well defined vertical orientation along the dermal suture line; 2) rounded cicatricial areas with radial branching septa of scarring tissue; 3) foreign body granuloma formation; 4) alignment of hystiocytes at the dermo-hypodermal border; 5) traumatic neuromas. The subcutaneous fat changes included: 1) lobular panniculitis with consistent presence of foam cells; 2) striking anisocytosis with pseudocystic degeneration and necrosis of adipocytes; 3) eritrocyte extravasation, mainly at the dermo-hypodermal border; 4) deep seated phlebitis. Post-surgical panniculitis is a lobular foam cell panniculitis characterized by simultaneous dermal and hypodermal changes, expression of the multi-faceted tissue response to a surgical trauma. This type of peculiar lipophagic response puts post-surgical panniculitis into the wider chapter of lipophage tissue response seen in atherosclerosis, glomerulosclerosis and some infectious models such as Mycobacterium tuberculosis and Chlamydia pneumoniae infections. Furthermore it may be seen as a reliable and convenient model for laboratory investigation on foam cell tissue response.

Comparison of skin incision vs. skin plus deep tissue incision on ongoing pain and spontaneous activity in dorsal horn neurons.

Surgery injures both skin and deep tissue causing pain at rest and evoked pain with activities. In this study, we examined the extent of injury by incision and dorsal horn neuron (DHN) spontaneous activity (SA) in rats that underwent a sham operation, skin incision or skin plus deep tissue incision. Pain behaviors were measured 1 day later followed by DHN recordings in the same rats. On postoperative day (POD) 1, guarding pain, assessed with an abbreviated pain score, was increased in the skin plus deep tissue incision group (7.0+/-0.7 vs. 0.1+/-0.6 in control, P<0.001), but not in the skin incision group (1.8+/-1.0); yet, mechanical and heat hyperalgesia were similar in both incised groups. In the rats that underwent skin plus deep tissue incision, more DHNs expressed SA (78.1% vs. 35.7% in control, P<0.01) and SA rate also tended to be greater (13.8+/-2.9 vs. 5.6+/-2.0 imp/s). Bupivacaine infiltration into the incision decreased SA in both skin incision and skin plus deep tissue incision (POD1) groups to the same level as in the sham-operated rats. In a separate group of rats that underwent skin plus deep tissue incision, guarding pain was not present (0.1+/-0.6) on POD7 and the percentage and rate of DHN SA were the same as in the sham control. These data demonstrate that incised deep tissue rather than skin is critical for the development of guarding pain and increased SA of DHNs. Skin incision alone is sufficient for primary mechanical and heat hyperalgesia.