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.

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.