Great saphenous vein leiomyosarcoma mimicking thrombosed aneurysm: A case report and review of the literature

Vascular leiomyosarcoma LMS. is an extremely rare subgroup of LMSs. Fewer than 50 cases of LMS originating from the great saphenous vein have been reported. In 43% of reported cases, LMS was misdiagnosed clinically. In our case, the patient was initially misdiagnosed as having a thrombosed aneurysm. This misdiagnosis could be due to the rarity of great saphenous vein LMS cases, for which a high index of suspicion is needed, and because no specific radiologic findings have been established for diagnosing LMSs. Masses presenting along the course of vessels should be suspected for malignancy, which can be helpful in performing definitive surgery and avoiding multiple surgeries.

Primary malignant venous tumors are extremely uncommon, with leiomyosarcomas (LMSs) of the saphenous vein even rarer, accounting for w1 in every 1 million malignant tumors. 1 Primary vascular LMSs (VLMSs) arise from the smooth muscle tissue of blood vessel walls.They are rarely diagnosed preoperatively. 2The tumor usually expands slowly and is difficult to diagnose before surgery because of its rarity and nonspecific symptoms.The most common clinical presentation reported in 60% of cases is a painless mass (Table ).Additionally, superficial vein thrombophlebitis has been reported. 3o specific laboratory or radiologic investigations are available that can help determine the definitive diagnosis.The only method available to confirm the diagnosis is histopathologic examination. 4In the lower limbs, the great saphenous vein (GSV) is the most common site of origin for primary VLMSs.In 80% of patients, a VLMS originates from the above the knee segment of the GSV (Table ).The prognosis and treatment depend on the tumor size, tumor grade, and ability to perform wide local excision with a 2-to 3-cm margin.

CASE REPORT
A 63-year-old woman presented with painless swelling in the groin.She was otherwise healthy and stated that the swelling had developed during the previous several months.On examination, her vital signs were normal, and a pulseless, painless swelling with normal color was noted at the medial aspect of her thigh.She had no previous medical issues or surgical interventions, and the laboratory study results were normal.
Before being referred to our center, Doppler ultrasound revealed a thrombosed aneurysmal dilation of the GSV close to the saphenofemoral junction without blood flow.However, for a more detailed assessment of the alleged aneurysm and to screen for potential venous aneurysms occurring simultaneously, abdominal and extremity magnetic resonance venography (MRV) was performed.MVR demonstrated an intraluminal mass that was filling and expanding the GSV and slightly extending to the common femoral vein, with mild to moderate inhomogeneous enhancement and some cystic areas (Figs 1-3), in favor of thrombosed aneurysmal dilation of the GSV.
The patient was scheduled for GSV aneurysm resection.
The patient received systemic heparinization before the procedure, and 5000 IU of heparin was administered during the proced-

DISCUSSION
Presentation.7][8] The inferior cava vein is the predominant venous location, accounting for almost one half of cases, followed by the pulmonary, renal, common femoral, saphenous, superior mesenteric, and ovarian veins and superior cava vein. 10Upper extremity vein sarcoma has also been reported. 11The first case of LMS of the inferior vena cava was reported in 1871 by Perl Tara. 12,13The GSV is the most frequent site of origin of LMSs in the lower extremities, 14 with <50 cases reported since it was first described by Aufrecht 15 in 1868.The size of VLMSs can vary greatly, with reported diameters ranging from 10 to 120 mm (mean, w43 mm).The age of patients with VLMS ranges from 2 to 85 years (median age, 57 years), with no gender predominance (Table ).
Diagnosis.In 43% of reported cases, LMS was not clinically suspected and was instead thought to be another condition, such as lipoma, neuroma, fibromatosis, venous aneurysm, enlarged lymph nodes, and others (Table ).In some cases, radiologic and tissue studies were unable to provide a definitive diagnosis before surgery, resulting in multiple surgeries being performed (Table ).The diagnosis of malignancy is not often made preoperatively. 16Based on the anatomic location, our clinical diagnosis initially suggested an enlarged femoral lymph node.Although magnetic resonance imaging (MRI) is highly accurate for diagnosing soft tissue tumors and is the preferred modality, for our patient, a GSV LMS was misdiagnosed as a thrombosed aneurysm using MRV and Doppler ultrasound.This might have been due to the lack of specific radiologic findings for LMS, the rarity of GSV LMS cases (requiring a high index of suspicion), the absence of usual MRI sequences (ie, T1, T2, gradient echo, diffusionweighted imaging/apparent diffusion coefficient of water), and the mild to moderate enhancement of some portions of the mass on MRV (Figs 1and3).Aneurysm of the proximal GSV segment has been reported; however, it is uncommon.The signal intensity on MRI for venous thrombosis is generally increased on T1-and T2-weighted images, with clear delineation of the thrombus from the vascular wall, which shows a low signal intensity. 17he presence of an intraluminal mass in a vein on MRI should suggest the diagnosis of venous LMS, which requires definitive operative excision.The preoperative diagnosis of a noncaval venous LMS allows for planning of resection without biopsy, reducing the risk of seeding by hemorrhage that can occur with incisional biopsy. 2 There is a belief that incisional biopsy could increase the risk of recurrence and metastasis by spreading tumor cells.Therefore, the significant advantage of avoiding incisional biopsy lies in terms of reducing seeding and minimizing the risk of recurrence and metastasis.Avoiding an incisional biopsy can be a significant advantage for the patient. 11ore than 25% of reported cases underwent tissue diagnosis before surgery (Table ).When diagnostic confirmation is necessary, direct tissue evaluation should be performed. 18This can be done through needle or core biopsies, followed by an open biopsy, if needed.A histologic diagnosis is crucial in determining the extent of resection, which can help in performing single-stage surgery with wide local excision instead of multiple surgeries.If the needle biopsy results are inconclusive, an incisional biopsy specimen will be necessary to guide the radiologic evaluation and confirm the presence of a superficial VLMS before surgical treatment. 19An excisional biopsy can be performed for primary lesions <3 cm, with incisional biopsy used for larger masses >3 cm. 12,20eatment.Currently, the mainstay treatment of venous LMSs appears to be wide excision of the tumor, combined with adjuvant radiotherapy. 21The goal of any surgical management plan is local disease control with preservation of limb function.The operative treatment of venous LMS involves wide surgical excision with a resection margin of 2 to 3 cm. 12,22Radical surgical excision locally appears to be appropriate for both primary lesions and isolated metastases. 23

Journal of Vascular Surgery Cases, Innovations and Techniques
Local recurrence is rare, and distant metastases to the thyroid, heart, scalp, bone, liver, skin, brain, and lungs have been frequently reported, with the lungs the most common site (Table ).If any form of adjuvant therapy is used, it is usually radiotherapy, with chemotherapy reserved for cases in which distant metastasis occurs. 22,24vidence supports the use of radiotherapy for the local management of soft tissue sarcomas in general, especially for larger lesions, 12,25 and for high-grade tumors. 14or smaller soft tissue sarcomas measuring <5 cm, adjunctive radiotherapy might not be necessary due to their significantly lower recurrence rate compared with that of larger lesions 8

CONCLUSIONS
This review should guide the approach to masses presenting along the course of vessels.Any intraluminal or extraluminal mass that presents close to a vessel should be suspected for malignancy.Due to their rarity, nonspecific symptoms, and nonspecific radiologic findings, VLMSs can be misdiagnosed.Therefore, a high level of suspicion is necessary.Also, it would be more helpful the for diagnosis, if MRI sequences (ie, T1, T2, gradient echo, diffusion-weighted imaging/apparent diffusion coefficient of water).were obtained, in addition to MRV.A diagnosis before the procedure could aid in performing definitive surgery and avoiding multiple surgeries.
ure.During the operation, a firm mass measuring 6 cm was found within the saphenous vein, without extraluminal extension.The common femoral vein was first clamped distally to prevent potential embolism and then clamped proximally.The progression into the saphenofemoral junction was managed by applying digital pressure and flushing in an attempt to extract the intraluminal extension.The mass was resected.At 2 weeks postoperatively, histopathologic examination revealed an LMS originating from the GSV, with the distal margin (close to the saphenofemoral junction) involved by the tumor.

Fig 3 .
Fig 3. Coronal view of contrast-enhanced magnetic resonance imaging (MRI) showing an inhomogeneously enhancing mass within the proximal great saphenous vein (GSV) expanding the lumen.Less prominent enhancement is present in its superior portion, mimicking a filling defect and thrombosis.

Fig 2 .
Fig 2. Coronal view showing extension of mass along course of great saphenous vein (GSV) into common femoral vein.Note mild enhancement of some portions of the mass, which led to the misdiagnosis.This was falsely reported as an aneurysmal dilation with internal thrombosis.

Fig 1 .
Fig 1. Axial view showing enhancing mass within great saphenous vein (GSV) with cystic spaces.

Table .
Reported cases of great saphenous vein (GSV) leiomyosarcoma Continued.