Posttraumatic lipomas: where do they really come from?

Right proximal tibia post-traumatic lipoma following a jogging fall

This case report describes a 70-year-old woman who presented with a lump at the right knee. She had had a fall while jogging two years previously, followed by the development of a painless mass at the injury site. The mass had gradually increased in size over time. At presentation the physical examination revealed a soft, ill-defined mass, and magnetic resonance imaging confirmed a well-circumscribed subcutaneous soft tissue mass consistent with a lipoma. Given the asymptomatic nature and well-defined characteristics of the mass, the patient opted for conservative management with observation. This case highlights the importance of considering post-traumatic lipoma in the differential diagnosis of soft tissue masses, particularly in patients with a history of trauma. Such masses should be regularly monitored to allow timely intervention if indicated.

A Novel Case of Cervical Lipoma Arising From Surgical Incision

Lipoma is a benign mesenchymal tumor primarily found in subcutaneous fat. Post-traumatic lipoma (PTL) sporadically associates with blunt of penetrating trauma, but the exact mechanism remains not fully understood. This article unveils a rare case of a 32-year-old male presenting with a cervical lipoma at a previous surgical incision, an unprecedented occurrence. The patient incidentally detected the mass and underwent complete excision, with pathology confirming the diagnosis. The etiology of PTL remains speculative, with proposed mechanisms postulating inflammatory chemokines inducing preadipocyte differentiation and acute trauma causing septal rupture, allowing lipoma formation. Notably, the prior use of blade in our patient's surgical procedure aligns with this hypothesis. The varied nature of trauma encompasses acute, blunt, and penetrating injuries. This case represents the second instance attributed to penetrating trauma and the first occurrence at a surgical incision site.

Deep Frontal Lipoma With Frontal Bone Invasion: Report of a Rare Case

Lipomas are benign masses of fatty tissue, and in the forehead, they may develop in the subcutaneous or deep fat tissue. While subcutaneous lipomas are common, deep forehead lipomas are unusual and rarely invade the underlying bone. Only a few cases have been reported in the literature, and even fewer cases are reported in children. We present a case of a slowly growing frontal mass corresponding to a deep lipoma responsible for frontal bone invasion, resulting in a bony defect reaching the dural space. Through this case, we aim to emphasize forehead lipomas' clinical and surgical characteristics.

A Scoring System That Predicts Difficult Lipoma Resection: Logistic Regression and Tenfold Cross-Validation Analysis

Introduction

Most lipomas are readily dissected and removed. However, some cases can pose surgical difficulties. This retrospective study sought to identify clinical and radiological risk factors that predict difficult lipoma resection and can be used in a clinically useful scoring system that predicts difficulty preoperatively.

Methods

The study cohort consisted of all consecutive patients who underwent resection of pathology-confirmed lipoma during 2016–2018 at a tertiary care referral center in Tokyo, Japan. Surgical difficulty was defined as difficulty separating some/all of the tumor from the surrounding tissue by hand and inability to extract the tumor in one piece. Descriptive, univariate, and multivariate logistic regression analyses were conducted to identify predictive factors. The predictive accuracy of the scoring system that included these factors was assessed by tenfold cross-validation analysis. Receiver-operating curve (ROC) analysis was conducted to identify the optimal cutoff score for predicting surgical difficulty.

Results

Of the 86 cases, 36% involved surgical difficulty. Multivariate analysis showed that subfascial intramuscular location (odds ratio 42.7, 95% confidence interval 3.0–608.0), broad touching of underlying structures (46.5, 3.7–586.0), in-flowing blood vessels (9.3, 1.1–78.5), and unclear boundaries (109.0, 1.1–1110.0) significantly predicted surgical difficulty. These factors were used to construct a 0–4 point scoring system (with one point per variable). On cross-validation, the accuracy of the scoring system was 82.4% (Cohen’s kappa of 0.57). ROC analysis showed that scores ≥ 2 predicted surgical difficulty with sensitivity and specificity of 55% and 98%, respectively.

Conclusions

Our scoring system accurately predicted lipoma resection difficulty and may help operators prepare, thereby facilitating surgery.

Head and Neck Lipomas at Uncommon Subsites: A Series of Four Cases

Lipomas are benign soft tissue tumors; the most common ones present in subcutaneous planes distributed throughout the body. However, there are few sites which are unusual location for lipomas. Here, we discuss the presentation of 4 cases of head and neck lipomas at unusual subsites. Though its prevalence is high in the body, lipomas are rarely seen in upper aerodigestive tract and these lesions can cause severe deglutition and respiratory distress problems in addition to cosmetic deformities. In the head and neck, most common location of lipoma is the cheek, followed by the tongue. Tonsillar lipomas are very rare. The mainstay treatment for lipomas is complete surgical excision and recurrence following complete removal is rarely known. We are here discussing a series of 4 cases of lipomas, presenting at uncommon subsites in head and neck region. These include lesions over neck, tongue, palate and tonsillar fossa. Lipomas are benign mesenchymal tumors, that are initially non bothersome. However, with increasing size they can cause severe aerodigestive problems with functional compromise and need complete surgical excision.

Lipoma and Its Doppelganger: The Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma

Lipomatous tumors are among the most common soft tissue lesions encountered by the general surgeon. Shared history and clinical presentation make differentiation between benign lipomas and low-grade liposarcomas a diagnostic dilemma. This article reviews the epidemiology, clinical history, diagnostic workup, management, natural history, and surveillance of benign lipomas and atypical lipomatous tumors/well-differentiated liposarcomas. Although it is important that aggressive, potentially malignant atypical lipomatous tumors and liposarcomas be managed in a multidisciplinary, preferably high-volume setting, it is equally as important for the nonspecialist general surgeon to be familiar with lipoma and its doppelganger-the well-differentiated liposarcoma.

Case report of a large lipoma discovered intraoperatively in a chronically irritated implantable cardioverter-defibrillator pocket

Background

The implantation of cardiac implantable electronic devices is a globally established therapy to treat cardiac arrhythmias with low complication rates. Apart from technical problems, however, complications can arise from the implanted material. This can lead to bleeding, infections, or chronic irritation of the generator pocket, resulting in swellings, seromas, perforations, or fistulas. However, the cause of tissue changes is not always clear, and therefore, we would like to report on a rare tissue degeneration diagnosed in a patient.

Case summary

After a history of ventricular fibrillation, a 46-year-old patient received an implantable cardioverter-defibrillator (ICD) for secondary prevention. Six years later, the generator pocket swelled without evidence of infection. With the suspected diagnosis of a chronically irritated pocket, the device was then surgically relocated. After a 2-year symptom-free period, the patient presented again with a severely swollen but only slightly painful device pocket. Once again, there were no signs of infection, and so the pocket was revised again, assuming a chronic irritant effusion. Intraoperatively, a lipomatous structure (12 × 6 × 3 cm) emerged from the subpectoral ICD pocket. After its complete removal, the histopathological examination revealed a lipoma. A bacterial genesis could be ruled out by microbiological samples, and the wound healed cosmetically well and without further discomfort.

Conclusion

This case shows that the reason of chronically irritated generator pockets, in addition to the usually known tissue changes, can also be tumours. Therefore, resected tissue should be examined histopathologically and, if indicated, specific therapy initiated.

Lump on the scalp of a child arising over a previous parietal fracture: growing skull fracture or post-traumatic lipoma?

A young girl was referred to our Institution for the appearance of a painless soft swelling in the right parietal region of the scalp. In the same site, the patient had a parietal bone fracture 1 year ago. In the suspicion of a growing skull fracture, the patient underwent radiological investigations. Ultrasound showed a soft, poorly vascularised swelling with parenchymatous content. The skull X-ray showed an apparent healing of the previous fracture. CT scan and MRI confirmed the correct healing of the fracture and described the presence of a lipomatous mass. The mass was surgically removed and histology confirmed the diagnosis of encapsulated lipoma. The postoperative period was uneventful, with no evidence of infections or recurrence in the 6-month follow-up.

Posttraumatic nuchal pseudolipoma in a high school athlete after weight training

Pseudolipomas are an uncommon clinical manifestation appearing as a non-encapsulated prominence of subcutaneous fat on MRI. Post-traumatic pseudolipomas (PTLs) are thought to arise from neoadipogenesis following acute or chronic trauma. These are most commonly located on the lower extremities, gluteal, and trochanteric regions. Here, we report a case of PTL in a high school athlete, arising in the posterior neck after weight training with performing barbell squats without neck padding. To our knowledge, this case represents a novel association between PTLs and weight training exercises.

Post-traumatic chest wall lipoma in a violinist: fact or fiction?

Lipomas are benign soft tissue tumours that can occur anywhere on the body and are rarely encountered on the chest. The pathophysiology between soft tissue trauma and lipoma development is not fully understood, and various theories have been presented. We present the case of a violinist with a 40-year occupational history who presented with swelling of the left upper chest wall. The microscopic sample of the resected lipoma showed inflammatory cells with fat necrosis, which are features thought to be involved in the development of a lipoma following soft tissue trauma.

Giant Posttraumatic Angiolipoma of the Forearm: A Case Report and Review of the Literature

Angiolipoma is a type of lipoma, a benign soft tissue tumor. It is distinguished by the excessive degree of vascular proliferation and the presence of mature adipocytes. It occurs commonly on the trunk and extremities. Angiolipomas larger than 4 cm are classified as "giant," and due to their size, histological evaluation is necessary to exclude malignancy. We report a case of a male patient who suffered from a giant noninfiltrating intramuscular angiolipoma which formed after venipuncture in the antecubital fossa. Clinical examination showed a palpable painless soft mass. Computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated a giant angiolipoma on the right forearm. Surgical removal of the mass was performed, and the biopsy was negative for malignancy. To the best of our knowledge, this is the first report in the literature of posttraumatic intramuscular angiolipoma. Physicians and orthopedic/general surgeons should be aware of the possibility of soft tissue masses in a posttrauma situation.

Giant Lipoma in the Fronto-Temporo-Parietal Region in an Adult Man: Case Report and Literature Review

Lipoma belongs to a group of benign mesenchymal tumors. It is in the form of soft masses of adipose tissue encapsulated by a thin layer of fibrous tissue and usually localized subcutaneously. The tumor most often appears in the upper part of the body. Lipomas tend to grow slowly and are small (less than 5cm) lesions. Larger tumors are rare. In this article, we present the case of a patient with a giant head lipoma in the fronto-temporo-parietal region. Both tumor size and location are unique and no such case has been described in the literature so far.

A Retrospective Study of Superficial Type Atypical Lipomatous Tumor

Atypical lipomatous tumor (ALT) has been defined as a well-differentiated liposarcoma exhibiting a higher frequency of a local recurrence after surgical resection. ALT is mainly classified into deep type and superficial type. Compared with deep type ALT, superficial type ALT is rarely observed. One of the most important issues is that little has been known about superficial type ALT and it is not easy to predict the presence of superficial type ALT before surgical resection. To clarify the clinical manifestations of superficial type ALT, we examined 15 cases with superficial type ALT and 118 cases with benign lipoma, and analyzed their differences in clinical characteristics and the findings of MRI test. In clinical characteristics, the tumor size of superficial type ALT was significantly greater than that of benign lipoma, and superficial type ALT showed a significantly higher frequency of the tumor size of more than 4 cm. Superficial type ALT exhibited poor tumor mobility and hardness with elastic soft. In addition, a significantly higher frequency of tumor location of superficial type ALT was observed in extremities. Among tumor sites at the trunk, buttocks, and shoulder were high frequent location in superficial type ALT. In an MRI examination, superficial type ALT exhibited a significantly higher frequency of the septal structures compared with benign lipoma. The combinations of clinical characteristics, including physical examinations, MRI, and histological examinations, are helpful for the diagnosis of superficial type ALT.

Chondrolipoma of the finger in a child: A case study

Chondrolipoma is, based on the limited case reports available, an extremely rare histological variant of lipoma with the proliferation of mature adipocytes containing an area of true hyaline cartilage. Chondrolipoma is characterized by adult onset and is often identified in the breast, pharynx and tongue. The current study presents a case of chondrolipoma of the finger in an 11 year-old girl. Physical examination indicated a well-defined elastic soft mass, measuring 2.5x2 cm, on the dorsal aspect of the proximal phalanx of the left middle finger. Magnetic resonance imaging (MRI) revealed a well-circumscribed lesion with heterogeneous signal intensity. On T1- and T2-weighted images, the lesion indicated a predominantly marked hyperintense signal containing linear hypointense regions, and on fat-suppressed short-tau inversion recovery sequences, the lesion indicated a predominant hypointensity, with linear regions displaying hyperintensity. Marginal excision of the tumor was performed. Histologically, the major component of the tumor was mature adipose tissue containing a limited area of mature hyaline cartilage matrix, without lipoblasts or malignancy. The postoperative course of the patient was excellent, with no local recurrence three years after surgery. To the best of our knowledge, the current study outlines the first pediatric case of chondrolipoma arising in the finger.

Deep forehead lipomas in children-A series and review

Deep forehead lipomas are rare in children and may be confused with other more concerning soft tissue masses. We describe four children with deep forehead lipomas, diagnosed between 2 months and 1 year of age, three of them congenital. Notable findings included association with intracranial lipoma and seizures in one patient and the development of marked alopecia overlying the lipoma in another. While deep forehead lipomas may become less visible over time, alopecia and non-syndromic extracutaneous involvement may be important associations.

Skin and Soft Tissue Lesions in a District Hospital in Central Nigeria: A Histopathological Study

Introduction. Skin and soft tissue diseases form a large and heterogeneous group of mesenchymal extraskeletal and dermatologic lesions in humans. Diseases of the skin and soft tissue can develop virtually anywhere in the body, extremities, the trunk, the retroperitoneum, the head, and the neck. Our study aims to review skin and soft tissue specimens from our centre describing the histopathological patterns.

Para-anal lipoma as a rare consequence to perineal trauma. Case-report and review of the literature

Introduction: Lipomas are the most common benign mesenchymal tumors which can be found in any part of the body. Nevertheless, their etiology and pathogenesis remain unknown. It is hypothesized that some of these lesions could result from an acute or chronic trauma. Patients and methods: We report a case of a 54-year-old man presenting a perineal lipoma which volume grew rapidly after he fell on his buttock, in the context of inaugural epileptic seizure. Pelvic MRI showed a voluminous fatty mass, measuring 6.6 × 5 × 9 cm without any signs of local invasion. Furthermore, we review the latest research on lipomas originating from traumatic lesion. Results: The mass was completely excised in one block under general anesthaesia, using an elliptical incision and a deep dissection. We did not close the skin incision in view of the cutaneous defect. Post-operative recovery was uneventful and the patient was discharged from hospital two days after the operation. Histopathology indicated a reorganised lipoma with no evidence of malignancy. Conclusion: Perineal lipomas are extremely rare, pathological examination of imaging guided biopsies are needed to exclude malignancy especially a well-differentiated liposarcoma. MRI remains the first option and radical surgical excision is the gold standard treatment.

A review of forehead lipomas: Important tips for the training surgeon

BACKGROUND

Forehead swellings can be caused by a variety of different pathologies, including lipomas. These benign lesions are composed of mature fat cells and often result in a poor cosmetic appearance causing significant psychosocial distress. Surgical removal is therefore frequently requested and they are often listed on a training local anaesthetic list. Thus, it is essential that trainees understand the nature of these lesions, their anatomical location and management, as well as differential diagnoses.

METHODS

A review of the available literature on forehead lipomas and their management was performed. Searches of both MEDLINE and EMBASE were conducted, with all full text articles published in English being included for analysis.

RESULTS

14 papers were included for analysis. Forehead lipomas are slow growing lesions with 100% presenting as a solitary swelling. They are more prevalent in males with mean age at presentation being 48 years. Their aetiology is unknown, however, blunt trauma has been postulated to contribute to their formation. Differential diagnoses include cysts and extension of intracranial lesions. Surgical intervention is the only recognised treatment, with a transverse, forehead-crease incision most commonly being adopted under local anaesthetic. Exploration beneath the frontalis muscle is often required in order to achieve their excision.

CONCLUSION

Important differential diagnoses must be excluded prior to attempted surgical excision of forehead lipomas. Surgeons must also be aware that the correct anatomical plane for these lesions is often beneath the frontalis muscle.

Subcutaneous lipomas: A minimally invasive method for resection of subcutaneous lipomas preserving retaining ligaments

Background

Lipomas are common benign tumors usually located in the subcutaneous tissues. Resection of lipomas frequently requires incisions equal to the diameter of the tumor. The “squeeze technique” with a small incision is well-described, but is frequently not successful, particularly for lipomas in the shoulder region. We report a method for resection of subcutaneous lipomas that preserves retaining ligaments.

Methods

Lipomas are characterized by high signal intensity on T1- and T2-weighted images on magnetic resonance imaging. Retaining ligaments demonstrate low signal intensity on T1-weighted images and high signal intensity on T2-weighted images with fat-suppression. Through a 1 in. incision, lipomas were detached from the retaining ligaments bluntly with a finger. Tumors were then extracted either in a piecemeal fashion or with the “squeeze technique.” Complete lipoma resection was visually confirmed through the incisions. For the current report, we analyzed 18 large lipomas resected by this method, with “large” defined as equal to or greater than 5 cm in diameter.

Results

The 18 patients included four males and 14 females with a mean age of 53.4 (26–72). The mean lipoma size was 6.6 cm (5–12). Locations included the shoulder in nine cases (50%), the upper arm in five cases (28%), the back in two cases (11%), and the thigh in two cases (11%). Retaining ligaments were identified by MRI in all cases. Lipomas were located between retaining ligaments at the periphery of the tumor. All three lipomas larger than 10 cm were located in the shoulder. There was no difference in the technical difficulty of resection of these compared with lipomas less than 10 cm in diameter. There were no cases of chronic pain or residual hypoesthesia at the incision sites.

Conclusions

The method is an easy and minimally invasive way to achieve complete resection, even for large lipomas, regardless of anatomical location. The method may contribute to reduction of side effects including residual hypoesthesia and chronic pain at the incision site, due to the small incision and preservation of retaining ligaments, which may contain cutaneous nerves.

Level of Evidence: Level IV, therapeutic study.

A Research of Soft Tissue Lipoma Genesis Factor With Immunohistochemical Analysis

INTRODUCTION

Lipoma is the most familiar soft-tissue tumor. But the etiology of lipoma remains imprecise. Sex steroid hormones such as estrogen have effects on muscle and adipose tissue development. There is now significant evidence that sex steroids are involved in the site specificities of adipose tissue metabolism. This association of adipose tissue metabolism between sex steroid hormones suggests a possible role for sex steroids in the pathogenesis of lipoma.

METHODS

To investigate this concept, the authors evaluated the expression of the estrogen receptor (ER) and the progesterone receptor (PR) in soft tissue lipoma in this study.In addition, angiogenesis and the production of angiogenic factors are fundamental for tumor progression in the form of growth, invasion, and metastasis. Epidermal growth factor receptor (EGFR) is involved in a signaling cascade that influences proliferation and other tumor-promoting activities. In this respect, the authors tried to define the correlation of soft tissue lipoma tumor cell and specific 2 immunohistologic markers, vascular endothelial growth factor (VEGF) and EGFR.The study population included patients who diagnosed with soft tissue lipoma, 20 independent patients were selected. All specimens were stained with hematoxylin and eosin. All slides were examined by a pathologist under a microscope. ER, PR, VEGF, and EGFR expression was analyzed by immunohistochemistry.

RESULT

ER, PR, and EGFR of tumor cell had significantly more negative than positive. And VEGF of tumor cell had significantly more positive than negative. There was no significantly difference between site of tumor and immunohistochemical stain.

DISCUSSION AND CONCLUSION

There are only a few studies for ER and PR in soft tissue related tumors. The authors estimated that the abnormal local proliferation and accumulation of adipocyte in soft tissue lipoma is related to sex steroid hormone action, especially estrogen and progesterone. But ER and PR of tumor cell had significantly more negative than positive in this study. The authors concluded that estrogen and progesterone are not impact factor of pathogenesis of soft tissue lipoma. Vascular endothelial growth factor of tumor cell had significantly more positive than negative. Angiogenesis is an essential factor for tumor growth. The VEGF expression of soft tissue lipoma can be understood in the same context. The authors need more study to reveal an association between lipoma and EGFR, because some patients of lipoma were positive to EGFR in this study.

Characterization of two distinct lipomas: a comparative analysis from surgical perspective

BACKGROUND

Lipomas are common benign soft tissue tumors that are well-circumscribed and encapsulated. However, adipose masses that are not demarcated from the surrounding fat are often encountered. Two distinct types of lipomas were analyzed from surgical perspective.

METHODS

Thirty patients were enrolled after lipoma excision and diagnosed with either encapsulated (n = 20) or non-encapsulated lipoma (n = 10). Comparison of clinical variables, histologic analyses and characterization of the lipoma adipose-derived stem cells (ASCs) between the two lipomas were performed.

RESULTS

Non-encapsulated lipomas were associated with older age at operation, larger tumor and increased seroma formation. The density of lymphatic vessels and gene expressions related to lymphatic vessel, inflammation and proliferation were increased in non-encapsulated lipoma. ASCs of non-encapsulated lipoma showed enhanced proliferation when cultured with serum.

CONCLUSIONS

Non-encapsulated lipomas and their ASCs showed distinct lymphatic histology and cellular response. These findings elucidated the pathogenesis and pathophysiology of lipomas.

Unusual Hypersensitivity Reaction to Iohexol During Epidural Steroid Injection Resulting in Lipoma Development: A Case Presentation

Epidural steroid injections are common interventional pain procedures for radicular pain when conservative therapies fail. We present the case of a 36-year-old woman with lumbar radicular pain who developed a hypersensitivity reaction to iohexol during a fluoroscopically guided interlaminar epidural steroid injection resulting in lipoma development. Mechanisms of anaphylactoid reaction and recommendations for lipoma treatment are described based on clinical presentation. With an increase in the number of injections performed for pain management, awareness of this complication may need to be included for informed consent.

LEVEL OF EVIDENCE

V.

A case of lipoma of parietal peritoneum causing abdominal pain

Lipomas are common benign tumors of mature adipose tissue, enclosed by thin fibrous capsules. They can occur on any part of the body; however, peritoneal lipoma is extremely rare. We encountered a case of a 75-year-old man presenting with intermittent abdominal pain, who had undergone right hemicolectomy due to colon cancer. Abdominal computerized tomography showed a well-defined heterogenous fatty mass measuring 4.5 × 3.5 cm in size, suggesting fat necrosis located in the abdominal wall. Laparotomy showed a very large soft mass of peritoneum. Pathologically, the tumor was diagnosed as lipoma containing fat necrosis located in parietal peritoneum not fixed to any organs, but with small bowel adhesion. Due to its rare etiologic origin and obscure cause of development, we report on a case of lipoma of parietal peritoneum causing abdominal pain.

State of diagnostic quandary solved by modern technology: a rare case of Madelung's disease

Madelung's disease is a neglected metabolic disease characterised by generalised multiple fatty tissue deposits. A 64-year-old Caucasian woman presented with generalised weakness and symptomatic hypoglycaemia with altered mental status. Physical examination showed very distinct physical characteristics with multiple lumps distributed over the upper body. Her neurological symptoms were solved by giving intravenous glucose and optimisation of medical treatment. Even though she had unique characteristics of Madelung's disease, many physicians, on several occasions, failed to recognise her 'hidden diagnosis'. This diagnostic uncertainty was able to be solved by searching the Internet for similar clinical features and images. This case demonstrates characteristics and unique features of a rare disease that can be seen in a female patient even though it is mostly found in males.

Giant lipoma of the back affecting quality of life

Lipomas are benign tumours composed of adipose tissue. They may be localized in almost all body parts and may be in a giant form. Some of these giant lipomas may transform malignity and cause problems in daily living and detoriate quality of life. Mass localization also restrict body functions. In the present study, a 72-year-old man who presented with a mass enlarged in a time period of two years and because of this could not lie in the supine position, sit in an erect position and dress easily, go outside because of his physical appearance. With surgical treatment a 38 × 22 × 21 cm mass weighing 3575 g was successfully resected. Postoperative early phase complications did not occur. During 48 months of postoperative period, any recurrence was not detected and the patient was free of all his complaints. Cosmetic and functional results of the surgery and patient satisfaction were excellent. After surgery patient's quality of life was improved and restriction of body function was disappeared.

•

The most common mesenchymal neoplasms in humans are lipomas.

•

Lipomas are typically slow-growing tumours; only a few grow to an exceptionally large size.

•

The effects of giant lipomas on daily living and quality of life should be evaluated as an indication for surgery.

Giant lipoma of posterior cervical region

Lipomas are the slow growing soft tissue tumors of benign nature. They commonly grow on torso and extremities but may also develop in head and neck region. Rarely lipomas can grow to acquire gigantic proportions, turning into an entity termed as giant lipoma. Such lipomas are entitled to immediate attention as they have a relatively high malignant potential. We report a rare case of giant cervical lipoma in an elderly gentleman, followed by a brief discussion on diagnosis and management of the disorder.

Nasal septal lipoma in a child: Pai syndrome or not?

Lipoma is the most common soft tissue mass in adults but it is uncommon in children. Nasal septal lipoma is an even more rare entity. In this report, a 12-year-old girl was presented with congenital nasal septal lipoma. She had permanent partial nasal obstruction on her right side and disfigurement of her right upper lip. CT scan revealed a lipoma-like mass in the septum plus an additional incidental finding of an intracranial lipoma. Further workup with MRI demonstrated corpus callosum agenesis with interhemispheric lipoma. To remove the mass, septoplasty, nasal lipoma excision and nasal vestibule V-Y advancement flap were performed. To close the lip a rotational advancement flap was required. Our case seemed to be a variety of Pai syndrome. We recommend imaging of the central nervous system in newborns with congenital lipomas located in the craniofacial midline to rule out the Pai syndrome.

Trauma as pathogenesis of a plantar forefoot fibrolipoma: first case and review of the literature

Lipomas and their variants are benign soft-tissue tumors that occur at any age and most frequently on the upper back and neck, shoulder, and abdomen. The foot is a relatively uncommon site for soft-tissue neoplasia and the etiology is not usually related to trauma. We describe a case of a pedunculated fibrolipoma of the forefoot that originated from a cut wound at the Atlantic Ocean. A brief review of the literature is also given.

Fibrolipomas masquerading as abdominal hernias

A 15-year-old Caucasian girl presented to her general practitioner with a tender, irreducible mass in the paraumbilical region. On examination, two small masses could be felt. She was referred to general surgery. Ultrasound imaging and MRI were unremarkable. However, clinical suspicion suggested multiple areas of abdominal wall herniation. The patient was admitted for elective surgery to exclude herniation. At operation, three subcutaneous masses were found but with no evidence of abdominal wall herniation. Histopathology results from the specimens showed mature adipose tissue mixed with fibrous deposits. There was no evidence of malignancy. A diagnosis of fibrolipoma was given.

Traumatic pseudolipoma causing facial asymmetry: An uncommon pathology and review of its pathogenesis

We present an uncommon case of traumatic pseudolipoma in a 24-year-old female, causing facial asymmetry. Literature review suggests trauma as a possible etiology for its pathogenesis, which was present in this case. Microscopically, sometimes it is difficult to differentiate between normal adipose tissue and lipoma. Clinician must provide accurate clinical information in order to make a definitive diagnosis of traumatic pseudolipoma. Its pathogenesis has also been highlighted in this article.

Giant submental lipoma: Case report and review of the literature

Lipomas may be located in all parts of the body and may be confused clinically with other soft tissue masses. They infrequently occur in the head and neck. A large neck mass (greater than 10 cm) with a rapid growth rate should raise concerns about a possible malignancy. Failure to distinguish a liposarcoma from a lipoma may represent a medicolegal pitfall. Surgical excision of a lipoma is often used as the definitive treatment modality, and alternative treatments described for lipomas range from liposuction to steroid injections. In the present study, a 60-year-old man who presented with a rapidly enlarging submental mass is described. A 15 cm x 12 cm mass was successfully removed. The surgery produced excellent cosmetic results and no functional impairment. An integrated review of the literature regarding etiology, epidemiology, diagnostic and treatment modalities of submental lipomas follows.

Intramuscular lipoma of the sternocleidomastoid muscle

Intramuscular lipoma is a rare benign mesenchymal tumor that infiltrates the skeletal muscle. These lipomas are usually found on the extremity, but rarely occur in the head and neck. To our knowledge, only 4 cases of intramuscular lipoma in the sternocleidomastoid muscle have been reported in the literature. The recurrence rate of intramuscular lipoma is high, and it shows the pattern of infiltration to tissues, and thus different from general lipomas, its resection should include adjacent normal muscular tissues. In addition, although rare, concerning intramuscular lipoma that developed in the head and neck area, because important structures are present densely in a small space, it is important to establish a preoperative plan by determining the size and location of the tumor through preoperative clinical and radiologic tests. We had a case of intramuscular lipoma in sternocleidomastoid muscle and resected the mass completely including a portion of attached muscles. The postoperative course was uneventful, and no evidence of recurrence occurred after 6 months of follow-up.

Unilateral pseudogynecomastia: an occupational hazard in manual metal-pressing factories?

BACKGROUND

Five cases of unilateral occupation-related pseudogynecomastia are presented. All the patients in these cases worked in the same metal-pressing factory.

METHODS

One patient with grade 4 unilateral gynecomastia in the right breast presented to the authors' outpatient department asking persistently for surgery. He also reported that all his male colleagues working in the same business (a total of 5) had different degrees of unilateral gynecomastia. Their line of work involved holding a long round rod under the axilla and then pressing the distal end of it firmly against a spinning metal plate. The patient underwent a superior pedicle breast reduction, with 1,800 ml of tissue removed from his right breast. Unfortunately, the patient experienced partial nipple loss. However, he was satisfied with the final result, and good symmetry was achieved.

RESULTS

All five patients who worked in the same metal-pressing factory presented with unilateral gynecomastia and were examined in our department. Their average age was 51.4 years. All the patients had normal hormonal and biochemical status, and the results of screening for toxins and heavy metal exposure were negative. All the patients were heavy smokers. At examination, none of the patients had nipple discharge or retraction, skin changes, galactorrhea, or lymphadenopathy. Examination showed one patient with grade 4, three patients had grade 2, and one patient with grade 1 unilateral gynecomastia.

CONCLUSIONS

The authors believe that gynecomastia may be considered an occupational risk in analogous metal-pressing factories because all the workers in this factory presented with some degree of unilateral gynecomastia. However, they emphasize that this may simply be an observational phenomenon without a true cause and effect relationship.

Angiofibrolipoma of the buccal mucosa: a case report

Angiofibrolipoma is a rare histopathological variant of lipoma, characterized by mature adipocytes, blood vessels and dense collagenous tissue. It is seldom seen in the oral and maxillofacial region. Clinically, as it shares macroscopic similarity with lipoma and fibroma, the diagnosis of angiofibrolipoma is only possible based on its histopathological features. The aim of this report is to present an unusual case of a 59-year-old female patient, who reported a pathological soft mass in the buccal mucosa of the left cheek which was present for 20 years. After excisional biopsy and histopathological evaluation of the sample, the diagnosis of angiofibrolipoma was made.

Cellular and molecular features of lipoma tissue: comparison with normal adipose tissue

BACKGROUND

Involvement of adipose-derived stem/progenitor/stromal cells (ASCs) in the development of lipomas has been suggested, but the pathogenesis and pathophysiology of this tumour remain unclear.

OBJECTIVES

To analyse cellular and transcriptional characteristics of lipoma tissue compared with normal adipose tissue, further to delineate differentiating features.

METHODS

For lipoma or normal adipose tissues, we used a new whole-mount staining enabling three-dimensional imaging of nonfixed and nonfrozen adipose tissue. Immunohistochemistry and real-time polymerase chain reaction for obesity-related genes were performed as well as comparative assay of the proliferative and adipogenic capacity of ASCs.

RESULTS

A large number of small adipocytes surrounded by CD34+/lectin- ASCs and increased numbers of Ki67+/CD34+ ASCs indicated enhanced adipogenesis in lipoma compared with normal adipose tissue. In contrast, cellular apoptosis was not enhanced in lipoma, suggesting that the enlargement of lipoma tissue may be due to a positive balance of adipocyte turnover (accelerated adipogenesis combined with nonenhanced apoptosis). Leptin mRNA was upregulated in lipoma, while adiponectin, tumour necrosis factor-alpha and glucose transporter 1 mRNA were downregulated and there were no apparent changes in hypoxia-inducible factor 1alpha, peroxisome proliferator-activated receptor-gamma and plasminogen activator inhibitor-1. These results suggested dysfunction of lipoma adipocytes similar to that in obesity, but indicated that lipoma tissue lacked several obesity-related phenomena such as ischaemia (hypoxia), macrophage infiltration, inflammatory reactions and enhanced glycolysis. ASCs from lipoma and normal adipose tissue showed similar proliferative and adipogenic capacity.

CONCLUSIONS

Our findings revealed that lipoma tissue shows a positive balance of adipocyte turnover involving proliferating ASCs and several transcriptional differences from adipose tissue enlargement in obesity.

Giant inframuscular lipoma disclosed 14 years after a blunt trauma: a case report

INTRODUCTION

Lipoma is the most frequent benign tumor of the soft tissue. This lesion is often asymptomatic except in cases of enormous masses compressing nervous-vascular structures. Although the diagnosis is mostly clinical, imaging tools are useful to confirm the adipose nature of the lesion and to define its anatomic border. Sometimes, lipomas may be the result of a previous trauma, such as in this patient.

CASE PRESENTATION

A 45-year-old man presented at our institution with a giant hard firm mass in the upper external quadrant of the right buttock disclosed after a weight loss diet. Subsequent magnetic resonance imaging showed a giant adipose mass developed beneath the large gluteal muscle and among the fibers of the medium and small gluteal muscles. When questioned on his medical history, the patient reported a blunt trauma of the lower back 14 years earlier. He underwent surgery and histological examination confirmed a giant lipoma.

CONCLUSION

Lipomas might result from a previous trauma. It is hypothesized that the trigger mechanism is activated by cytokine and growth factors released after the trauma. We herein present an exceptional case of a giant post-traumatic lipoma which caused a painful compression on the right sciatic nerve.

Large vulvar lipoma in an adolescent: a case report

Lipomas are the most common benign tumors of soft tissues. However, conventional lipomas have been reported only rarely as presenting in the vulva. We present a case of vulvar lipoma in a 17-yr-old woman, possibly caused by chronic intermittent irritation.

Post-traumatic soft tissue tumors: case report and review of the literature a propos a post-traumatic paraspinal desmoid tumor

Background

Antecedent trauma has been implicated in the causation of soft tissue tumors. Several criteria have been established to define a cause-and-effect relationship. We postulate possible mechanisms in the genesis of soft tissue tumors following antecedent traumatic injury.

Case presentation

We present a 27-year-old woman with a paraspinal desmoid tumor, diagnosed 3-years following a motor vehicle accident. Literature is reviewed.

Conclusion

Soft tissue tumors arising at the site of previous trauma may be desmoids, pseudolipomas or rarely, other soft tissue growths. The cause-and-effect issue of desmoid or other soft tissue tumors goes beyond their diagnosis and treatment. Surgeons should be acquainted with this diagnostic entity as it may also involve questions of longer follow-up and compensation and disability privileges.

Posttraumatic lipoma: fact or fiction?

BACKGROUND

Both trauma and lipomas are a common occurrence in surgical practice. Lipomas are usually benign adipose tumors with as-yet unexplained pathogenesis and etiology. A link between soft tissue trauma and the formation of lipomas has been described, with the latter being named posttraumatic lipomas.

METHODS

Twenty-three cases of posttraumatic lipomas in 19 patients treated at our institution between August 2001 and January 2005 were reviewed with regard to medical history, magnetic resonance imaging findings, intraoperative findings, clinical chemistry, and histology.

RESULTS

The mean age of the patients was 50.0 years (+/-15.5). The average time between soft tissue trauma and lipoma formation was 2.6 years (range, 0.5-6.0 years). Sixteen of the 19 patients reported extensive and slowly resolving hematoma formation after the traumatic event. Nine of 23 lipomas were found on the upper extremities, 3 on the lower extremities, 9 on the trunk, and 2 on the face. All tumors were located epifascially. Twenty-two lipomas were removed by simple excision and, in one case, aspiration lipectomy was performed. Pathology demonstrated capsulated and noncapsulated benign adipose tumors in 23 cases. The average body mass index, amounted to 30 kg/m(2) (+/-7.6 kg/m(2)). Seven patients without known bleeding disorders presented with an elevated partial thromboplastin time.

CONCLUSIONS

The pathogenetic link between soft tissue trauma and the formation of posttraumatic lipomas is still controversially discussed. There are 2 potential explanations to correlate soft tissue trauma and adipose tissue tumor growth. The first is the formation of so-called posttraumatic pseudolipomas by prolapsing adipose tissue through fascia resulting from direct impact. A second possibility points toward lipoma formation as a result of preadipocyte differentiation and proliferation mediated by cytokine release following soft tissue trauma and hematoma formation.

Post-traumatic pseudolipoma of the forehead

A forehead lipoma is a rare finding in a child, and one that penetrates the underlying layers of muscle and bone to attach to dura has not previously been reported. Two such cases, both in children who underwent uneventful deliveries aided by forceps, are presented. Both lesions were present at birth and, based on clinical findings, were originally thought to be dermoid cysts. Dermoid cysts could not be ruled out with computed tomography and magnetic resonance imaging. Histopathology identified fibrofatty tissue consistent with lipoma. Both lesions extended from the subcutaneous tissue through the frontalis muscle and frontal bone to the dura. Given these findings and the history of forceps delivery, the most likely diagnosis is post-traumatic pseudolipoma. This lesion should be considered in the differential diagnosis of congenital lesions of the forehead, particularly if there is a history of forceps delivery or other trauma to the area.

Lipomas after blunt soft tissue trauma: are they real? Analysis of 31 cases

BACKGROUND

Soft tissue trauma and lipomas are common occurrences in surgical practice. Lipomas are defined as benign tumours of adipose tissue with so far unexplained pathogenesis and aetiology. A link between preceding blunt soft tissue trauma at the site of the tumour and the formation of lipomas has been described earlier. These soft tissue tumours have been named 'post-traumatic lipomas'.

OBJECTIVES

In a retrospective review, to analyse all patients with benign adipose tissue tumours treated at our institution between August 2001 and January 2007.

METHODS

All cases were reviewed regarding medical history, magnetic resonance imaging findings, intraoperative findings, clinical chemistry and histology.

RESULTS

In 170 patients presenting with lipomas, 34 lipomas in 31 patients were identified as post-traumatic. The mean +/- SD age of the patients with post-traumatic lipomas was 52 +/- 14.5 years. The mean time elapsed between soft tissue trauma and lipoma formation was 2.0 years (range 0.5-5). Twenty-five of the 31 patients reported an extensive and slowly resolving haematoma after blunt tissue trauma at the site of lipoma formation. The mean +/- SD body mass index was 29.0 +/- 7.6 kg m(-2). Fourteen of 31 patients presented with an elevated partial thromboplastin time. Eleven of 34 lipomas were found on the upper extremities, five on the lower extremities, 13 on the trunk, and two on the face. All tumours were located subcutaneously, superficial to the musculofascial system. Thirty-three lipomas were removed by surgical excision and one by liposuction following an incisional biopsy. Histological examination revealed capsulated and noncapsulated benign adipose tissue in all 34 tumours.

CONCLUSIONS

The existence of a pathogenic link between blunt soft tissue trauma and the formation of post-traumatic lipomas is still controversial. Two potential mechanisms are discussed. Firstly, the formation of so-called post-traumatic 'pseudolipomas' may result from a prolapse of adipose tissue through fascia induced by direct impact. Alternatively, lipoma formation may be explained as a result of preadipocyte differentiation and proliferation mediated by cytokine release following soft tissue damage after blunt trauma and haematoma formation.

Diagnostik und Therapie posttraumatischer Pseudolipome

BACKGROUND

Both trauma and lipomas are frequently encountered in day-to-day clinical practice. Although lipomas are defined both clinically and pathologically as benign fatty tissue tumours, their aetiology is still not clear.

METHODS

In this study 19 patients with 23 posttraumatic lipomas were analysed retrospectively with reference to ultrasound and MRI diagnosis, history, laboratory results and histopathological investigations.

RESULTS

The mean age of the patients was 50.5 years (+/-15.5). The causative soft tissue trauma dated back an average of 2.6 years. When the histories were taken, 16 of the 19 patients reported vast, slow-resorbing posttraumatic haematomas. Nine of the 23 lipomas were sited in the upper extremity, 3 in the lower extremity, 9 in the trunk and 2 in the face. All were located epifascially. In 22 cases the lipomas were excised, and in 1 case the lipoma was removed by liposuction. Histological examination demonstrated capsulated benign fatty tissue tumours in 19 cases and uncapsulated benign fatty tissue tumours in 4. The average body mass index (BMI) was 29 kg/m(2). Removal of the tumour resulted in a good aesthetic result in all patients.

CONCLUSIONS

The link between a blunt soft tissue injury and the development of a posttraumatic lipoma is still the subject of controversy; there are two mechanisms that seem more likely than any others proposed: (1) the "pseudolipoma" as the result of a prolapse of fatty tissue as an immediate result of trauma and (2) the development of a lipoma by way of differentiation of pre-adipocytes mediated by cytokines released by a posttraumatic haematoma. There appears to be a correlation between an increased partial thromboplastin time (PTT) and the development of posttraumatic lipomas. The generalised increase in the volume of body fat documented by the elevated BMI supports the idea that lipomas arise from the prolapse of adipose tissue. However, there is no single mechanistic explanation for the development of posttraumatic lipomas. They are probably caused by multiple factors and not by isolated pathological mechanisms.

Posttraumatic pseudolipoma: MRI appearances

The goal of this study was to describe the MRI characteristics of posttraumatic pseudolipomas. Ten patients with previous history of blunt trauma or local surgery were investigated with MRI at the level of their deformity. The etiology was blunt trauma in eight patients and postoperative trauma in two. For all patients medical documentation, in the form of clinical history and physical examination, confirmed that a visible hematoma was present acutely at the same location following the injury and that the contour deformity subsequently appeared. All patients underwent liposuction. Preoperative bilateral MRI examinations were performed on all patients. The mean clinical follow-up was 17.8 months. MRI examinations were interpreted in consensus by two experienced musculoskeletal radiologists with attention to fatty extension (subcutaneous fatty thickness and anatomical extension), asymmetry compared with the asymptomatic side, the presence or absence of fibrous septae or nonfatty components, and patterns of contrast enhancement. Ten posttraumatic pseudolipomas were identified. Clinically, they showed as subcutaneous masses with the consistency of normal adipose tissue. Their locations were the abdomen (n=1), hip (n=1), the upper thigh (n=6), the knee (n=1), and the ankle (n=1). On MRI examinations, using the contralateral side as a control, pseudolipomas appeared as focal fatty masses without a capsule or contrast enhancement. Posttraumatic pseudolipomas may develop at a site of blunt trauma or surgical procedures often antedated by a soft tissue hematoma. Characteristic MRI findings are unencapsulated subcutaneous fatty masses without contrast enhancement.