Massive localized lymphedema (MLL) is a benign overgrowth of lymphoproliferative tissue that is primarily observed in adults with class III obesity. Patients present with a painless mass that has usually been present for a considerable period. Consultation of a healthcare professional typically takes place when MLL-related complaints interfere with daily living. Massive localized lymphedema is often termed "pseudosarcoma" due to its clinical similarity to sarcoma. Surgical excision is necessary to improve mobility, prevent recurrent infections, and rule out malignancy, but can be high-risk for individuals with class III obesity and multiple comorbidities. In this report, the authors present the case of a 47-year-old woman with a body mass index of 73 kg/m2 and MLL of the right medial thigh. She was successfully diagnosed and managed by local necrosectomy, wound debridement, maggot debridement therapy, and negative-pressure wound therapy by using a vacuum-assisted closure device. The diagnosis of MLL can be challenging because of its similarity to sarcoma; its pathogenesis and management are not completely elucidated. Despite surgery being the best described treatment, such an intervention itself can be challenging because patients often have multiple comorbidities and delayed diagnosis. The authors recommend that clinicians should consider nonsurgical treatment of MLL in high-risk patients who have necrotic wounds with fluid loss. The use of less invasive methods such as maggot debridement therapy followed by negative-pressure wound therapy can be useful in high-risk patients.
Massive localized lymphedema (MLL) is characterized by benign overgrowth of lymphoproliferative tissue, primarily affecting adults with class III obesity. Its incidence appears to be on the rise in the Western world due to the current obesity epidemic. Farshid and Weiss first described this condition in 1998, proposing that localized obstruction of lymphatic drainage in the limbs results from anatomic changes associated with obesity. Although MLL typically manifests in the medial thighs, it can also occur at other sites. Occasionally, factors other than obesity, such as hypothyroidism, paresis, or prior inguinal lymphadenectomy, may contribute to MLL development. Complications arise due to compromised lymphatic and blood flow.
Patients with MLL usually present with a massive, pendulous, painless mass that has been present for a significant duration before seeking medical consultation. Massive localized lymphedema lesions can become so large that ambulation becomes difficult or infection occurs. The affected skin thickens, becomes keratinized, and may develop scales, increasing susceptibility to skin cracking, wounds, and infections. Some cases exhibit a peau d'orange appearance and lymphorrhea.
Despite its characteristic presentation and findings on macroscopic and microscopic examination, diagnosing MLL remains challenging for clinicians and pathologists alike. Histologically, MLL is often mistaken for well-differentiated liposarcoma or extra-abdominal fibromatosis. Therefore, because of its clinical resemblance to sarcoma, MLL is sometimes referred to as "pseudosarcoma." Histopathologically, lymphoproliferative tissue in MLL shows a thickened epidermis, dilated lymphatic channels, dermal fibrosis, and extensive interstitial edema, and frequently exhibits vascular proliferation and inflammatory changes. Awareness of the potential for malignant transformation to sarcoma in chronic lymphedematous areas underscores the importance of vigilant patient monitoring. Imaging modalities such as computed tomography or MRI reveal a diffuse reticular pattern with extensive subcutaneous edema, typically confined to the subcutaneous tissue without involving muscle.
Accurate diagnosis is crucial for effective management and prevention of complications associated with MLL. Conservative treatment options include physical therapy, weight management, compression therapy, hygiene measures, and prophylactic antibiotics to prevent skin infections. Unlike classic lymphedema, MLL is localized and irreversible, necessitating surgical intervention to enhance mobility, mitigate recurrent infections, and exclude malignancy when diagnostic uncertainty persists. Long-term follow-up is recommended posttreatment to monitor for recurrence and potential malignant transformation.
There are high surgical risks associated with excision under general anesthesia in patients with class III obesity and multiple comorbidities. In this report, the authors describe their successful management of MLL in a 47-year-old woman with a lesion on the right proximal thigh, without surgical excision under general anesthesia. The patient provided informed consent for publication of the case details and associated images.
CASE PRESENTATION
A 47-year-old woman presented with an unclear history of an enlarging, purple-tinted mass on her right upper leg, located between the groin and the knee. Medical history contained hypertension and class III obesity with a body mass index of 73 kg/m. She presented with sudden acute wound fluid and a high fever of 39.2 °C. Her biochemical profile showed a C-reactive protein value of 375 mg/L (reference range [RR], <10 mg/L), leukocytes of 8.6 × 10/L (RR, 4-10 × 10/L), and an estimated glomerular filtration rate of 8 mL/min per 1.73 m (RR, >90 mL/min per 1.73 m). Because of her septic condition with acute tubular necrosis, she was hospitalized in the ICU; she received ceftriaxone by IV infusion and underwent temporary kidney dialysis.
Following recovery, the patient was referred to the general surgery department for evaluation of possible sarcoma. Her physician changed her antibiotics to amoxicillin/clavulanic acid and sulfamethoxazole/trimethoprim after a wound culture identified Acinetobacter species and Enterococcus faecalis. Biopsies showed inflammation, necrosis, fat necrosis, and fibrin, with no signs of malignancy present. After 3 weeks, she was transferred to the authors' academic hospital for specialized wound care; no further antibiotics were administered.
On examination, there was a large, pedunculated mass of the medial-proximal right thigh; the overlying skin had a necrotic appearance (Figure 1A). The subcutaneous tissue was detached (subdermal involvement), causing the patient to experience fluid loss from the wound. The skin of the lower leg showed a hyperkeratotic cobblestone pattern. The neurovascularization of the lower limb was intact but had signs of lymphedema.
Computed tomography imaging revealed pronounced induration on the medial aspect of the right upper leg (Figure 2A). This induration was confined to the subcutaneous tissue without involving the muscle compartment. Normal fat tissue was observed in some parts of the same area, with no evidence of focal masses. The findings were indicative of severe cellulitis.
An additional MRI scan demonstrated an extensive abnormal stained lesion in the deep subcutaneous fatty tissue, without clear margins or involvement of a muscular compartment (Figure 2B, C). The mass was approximated to be 18 × 18 cm in the transverse plane and 25 cm in the craniocaudal direction. The radiologists concluded that it was suggestive of MLL of the thigh, mimicking liposarcoma. Similar aspects were observed to a lesser degree on the opposite side, as well as in the right lower leg. Although visible on imaging, no wounds were noted at these locations.
A multidisciplinary meeting concluded with the diagnosis of MLL. The wound care nurse specialist applied a gel composed of alkaline ionized seawater with sea salt, sodium hypochlorite, and lithium magnesium sodium silicate (ActiMaris, We Medical) daily to moisten the wound bed. In addition, an absorbent, nonwoven, silver-containing antimicrobial dressing composed of cellulose ethyl sulfonate fibers (Durafiber*Ag, Smith & Nephew) was applied three times per week by the wound care nurse to absorb excess fluid while providing a moist environment with antimicrobial activity.
The patient was scheduled for surgical evaluation and potential excision of the lesion. However, due to her unclear history of previous resuscitation following general anesthesia, both the surgical team and the patient were hesitant to proceed with a procedure under general anesthesia. To mitigate potential risks, the team decided to perform a necrosectomy initially in the surgical ward. The patient received only thromboembolic prophylaxis with subcutaneous heparin. Two (resident) surgeons performed the necrosectomy using regular scissors for the dissection (Figure 1B). The excised mass was 10 × 25 cm and weighed approximately 2.5 kg (2.2 lb). It was sent to pathology to rule out malignancy and confirm the MLL diagnosis. The report showed no vital, necrotic tissue without associated inflammation. Also, there was no evidence of malignancy.
At 3 days postexcision, the wound was heavily exudative and developed yellow and black necrosis. The surgical resident performed an additional debridement. Because the necrotic tissue seemed to be deep, the surgical team decided to begin maggot debridement therapy (MDT) 6 days after the first necrosectomy. After limited additional debridement, two biobags containing 300 maggots in total were placed in the wound (Figure 3A). A calcium-alginate dressing (Algisite, Smith & Nephew) was used in the wound bed to create and maintain a moist wound environment, and the wound was covered with a dry mesh. The team paid particular attention to moisture levels at the wound site: if the wound was too dry, the maggots were moistened with 0.9% sodium chloride, and if the mesh was wet, an absorbent bandage was applied.
After 5 days of MDT, a much cleaner wound bed was observed (Figure 3B). The surgical team removed a necrotic wound edge at the upper lateral area with a regular stitch cutter and then placed two new bags totaling 300 maggots inside the wound. These remained in place for another 3 days. After 8 days of MDT in total, the wound was obviously cleaner, and the necrotic tissue previously noted had almost vanished (Figure 3C). The wound care nurse observed granulation, yellow deliquescent necrosis, and greenish serous exudate, possibly due to a Pseudomonas infection. Overall, the wound care providers felt that MDT was very effective.
Following MDT, the patient received negative-pressure wound therapy (NPWT) with a vacuum-assisted closure (VAC) device. The providers chose this modality because it is a well-established technique for managing complicated wounds through a granulation-healing process. The VAC device was successfully applied to the wound site with an alternating negative pressure of 100 mm Hg for 10 minutes and 25 mm Hg for 2 minutes. The VAC device was replaced every 4 days. By the fourth day of NPWT, the wound appeared clean, granulated, and visibly shallower, with some signs of yellow necrosis and exudate on the cranial side (Figure 4A). The wound care nurse flushed the wound with tap water, and the same gel composed of alkaline ionized seawater for the wound bed was applied. In addition, a nanocrystalline silver product (Acticoat, Smith & Nephew) was applied as an antimicrobial barrier. The VAC device was then applied to the defect in the same intermittent fashion. After 1 week of NPWT, the amount of yellow necrosis and exudate had decreased, the wound edges were undermining, and more granulation tissue was observed (Figure 4B). The VAC therapy was continued with the same alternating pressure.
Further observations indicated that the wound continued to heal well, remaining clean with ongoing granulation proliferation and wound edges drawing together. The patient was then transferred to her local hospital 2 weeks after the start of the NPWT, where NPWT was continued until the wound achieved full closure. The patient was discharged from the local hospital after 2 months. Follow-up results after 19 months showed complete wound healing. The Table outlines the treatment steps.
DISCUSSION
Massive localized lymphedema typically presents as a large, pendulous mass on the proximal extremities. Although MLL commonly occurs in the medial aspect of the limbs because of the preponderance of lymphatics in this area, it can develop at different locations, such as the anterior abdominal wall, scrotum, vulva, lower legs, popliteal, groin, and penis.
The pathogenesis of MLL may include a combination of lymphedema and ischemia. The continuous mechanical stretching caused by the weight of the tissue itself is thought to create an ischemic microenvironment, simulating a wound-like process. This process encourages the formation of fibrosis and in turn causes lobulation of the fat tissue. Although histologically similar to sarcoma, MLL has emerged as a different, benign manifestation.
Recent reports highlight that this pseudosarcomatous benign manifestation primarily occurs among those with obesity who have a body mass index greater than 56 kg/m and is more frequently diagnosed in women. Other factors such as hypothyroidism, paresis, and prior lymphadenectomy in case of inguinal surgery have been described as well.
Apart from the paramount value of correct diagnosis, treatment of MLL is necessary to prevent further complications. Jabbar et al concluded that MLL is best treated by surgical excision facilitated by pulleys and different incisions to obtain primary closure. Hou et al elected to perform surgical resection alongside a bariatric surgical procedure to reduce the risk of recurrence. Although surgery remains the current optimal treatment option, performing such an intervention can be challenging because patients frequently delay seeking medical attention. In these cases, MLL tissue lacks encapsulation and is filled with lymphatic fluid, and its margins are difficult to delineate. The neovascularization and lymphatics can result in blood and fluid loss during a surgical approach. Incisions tend to either heal slowly or break down as a result of the lymphatic obstruction and decreased oxygen supply.
To the authors' knowledge, no previous cases have been published that describe treating an open, necrotic MLL wound with acute fluid loss. Consequently, there is no prior description of less invasive methods for such cases. Contrary to general MLL treatment reports, the surgical team opted not to perform an excision under general anesthesia because of the potential risks. Instead, they chose local necrosectomy, wound debridement, MDT, and NPWT using a VAC device.
CONCLUSIONS
Massive localized lymphedema remains underreported in the literature, particularly regarding its management. Given the current obesity epidemic, clinicians must be aware of this condition and its treatment options and take care not to mistake MLL for a soft-tissue malignancy such as sarcoma.
Surgical excision under general anesthesia can be high-risk for individuals with class III obesity and multiple comorbidities. Therefore, the authors recommend considering alternative treatments for nonhealing wounds, such as local necrosectomy and debridement followed by MDT and NPWT, as presented in this case. More case reports are needed to better understand the pathogenesis of MLL and evaluate management with these less invasive methods. Preventing obesity and promoting early weight loss are key to preventing MLL and its complications.