An elderly patient with low-grade fibromyxoid sarcoma with early postoperative recurrences and metastases: a case report

Abstract

Background

Low-grade fibromyxoid sarcoma is a rare soft tissue tumor characterized by a benign histological appearance but with a high potential for recurrence and metastasis. First described by Evans in 1987, recurrence and metastasis can occur decades after the initial diagnosis, complicating long-term management.

Case presentation

We report the case of an 83-year-old Jewish female patient diagnosed with low-grade fibromyxoid sarcoma in her right shoulder. The patient underwent wide resection with positive margins, followed by regular follow-ups. At 9 months postoperatively, she developed recurrence involving the right trapezius, thoracic vertebrae, ribs, and pleural cavity, a second local resection was performed. At 2 years post-surgery, the patient remains recurrence free.

Conclusion

Low-grade fibromyxoid sarcoma, though rare, presents a high risk for recurrence and metastasis. Long-term follow-up and vigilant monitoring are crucial, particularly in cases where positive surgical margins are involved. Surgery remains the cornerstone of treatment, but ongoing research into systemic therapies may offer new options for managing metastatic or recurrent low-grade fibromyxoid sarcoma in the future.

Background

Low-grade fibromyxoid sarcoma (LGFMS) was first recognized by Evans in 1987 when he described a bland fibromyxoid neoplasm arising in the deep soft tissues of two young women who subsequently developed metastases [1]. Although this is a rare entity, it is reasonable to speculate that it is probably more common than reported in medical literature owing to the likelihood of misdiagnosis with other low-grade fibrous or myxoid soft-tissue neoplasms.

LGFMS occurs more frequently in young to middle-aged adults; however, cases have been reported in patients between 6 and 65 years of age. Men are more commonly affected than women [2, 3]. The usual presentation is a slow-growing, painless mass. LGFMS is frequently surrounded by skeletal muscle [2, 3] and tends to involve deep soft tissues of the thigh, inguinal region, or chest wall. Less commonly, it can involve the shoulder or axilla [4].

Multiple studies have shown recurrence rates of 1–9% and metastasis rates of 6–27%, primarily in the lungs, pleura, and chest wall [5,6,7]. However, these rates increase with long-term follow-up. Evans’ study, which had the longest follow-up (at least 5 years), reported a local recurrence rate of 64% (up to 15 years after diagnosis), metastases in 45% (up to 45 years after diagnosis), and death due to disease in 42% of cases (ranging from 3 to 42 years after diagnosis) [8].

Owing to the rarity of this neoplasm, the role of chemotherapy and radiotherapy remains unknown. Here, we present a rare case of LGFMS in an elderly female patient who experienced recurrence within months of resection, along with our experience from this case.

Case presentation

An 83-year-old Jewish female patient was diagnosed with low-grade fibromyxoid sarcoma (LGFMS) in her right shoulder. The patient subsequently underwent a wide resection of the local recurrent tumor, with a 1 cm margin in all directions around the mass or the scar from the previous surgery, and she attended follow-up exams every 3 months, with appropriate imaging for evaluation.

At her 9-month follow-up, the patient reported difficulty moving her neck and discomfort around the surgical site (Fig. 1). On examination, she had restricted neck movement to the right, the surgical site was unremarkable, with no palpable mass. Magnetic resonance imaging (MRI) revealed a soft tissue mass in the right trapezius extending to the thoracic vertebrae, ribs, and pleural cavity (Fig. 2). A biopsy confirmed recurrence of LGFMS, with skin, subcutaneous tissue, and adjacent fibromuscular and fatty tissue infiltrated by the tumor, which stained positive for MUC-4.

Fig. 1

Timeline depicting the clinical course of low-grade fibromyxoid sarcoma treatment and follow-up from January 2020 to January 2023. Blue dot indicates initial wide resection (12/27/2020), red dot shows biopsy confirmation of recurrence (10/12/2021), and green dot represents second wide resection (04/11/2022). The timeline extends to show the complete 2-year follow-up period post initial surgery, ending on 12/27/2022, during which no further recurrence was observed

Fig. 2

T2 magnetic resonance imaging section indicating tumor invasion into the vertebrae (white arrows); a coronal image, b axial image

A multidisciplinary surgical team, including orthopedic oncology, spine, cardiothoracic, and plastic surgery units, performed the resection to remove the tumor and involved structures (Fig. 3).

Fig. 3

Picture taken during the surgery showing the lung, spinal cord, and surrounding tissue after removing the involved vertebrae and ribs

Nearly 2 years postoperatively, the patient remains under close surveillance with no evidence of recurrence. She is doing well and reports no complaints.

Discussion

Low-grade fibromyxoid sarcoma (LGFMS), first described by Evans [1] in 1987, is known for its deceptively benign histological appearance, despite its high potential for recurrence and metastasis. Early reports by Evans indicated that 7 out of 12 patients developed distant metastases, with follow-up periods ranging from 5.5 to 50 years [2]. However, a study by Folpe et al. [9] reported lower recurrence (9%) and distant metastasis (6%) rates in a cohort of 54 patients, potentially owing to more aggressive surgical interventions and shorter follow-up periods (median of 24 months).

Recurrence in LGFMS is often delayed, sometimes occurring years after initial treatment. For instance, Evans’ later reports documented a median time to local recurrence of 3.5 years, with some cases recurring up to 15 years post-treatment, while metastasis occurred up to 45 years after diagnosis, with a median of 5 years [8].

Most LGFMS tumors are well circumscribed but lack a capsule, allowing for local infiltration, which complicates complete surgical resection [10]. Prognosis is closely tied to tumor size, invasion to adjacent tissues, and surgical margin status [11]. Patients with negative surgical margins tend to have a lower recurrence risk and longer recurrence-free intervals [12]. In our case, the presence of positive surgical margins likely contributed to the early postoperative recurrences observed.

Chemotherapy and radiotherapy are generally ineffective in LGFMS owing to the tumor’s low mitotic activity [13]. Our patient’s treatment plan, consistent with most literature, focused solely on surgical management, as she did not receive chemotherapy or radiotherapy. While systemic therapies remain limited, surgery continues to be the mainstay treatment for both initial and recurrent cases. In cases of metastasis, particularly in challenging locations such as the vertebrae, surgical intervention remains the optimal approach, as was demonstrated in our case [13].

Emerging treatments, such as trabectedin, have shown promise in managing metastatic LGFMS, potentially targeting the FUS::CREB3L2 fusion gene [14]. However, our patient did not undergo this therapy, as her recurrence was managed surgically. More research is necessary to better understand the role of systemic therapies in patients with early metastatic LGFMS.

Conclusion

In our case, early postoperative recurrences may have been associated with a positive margin during the initial operation. The patient underwent a wide tumor resection but developed metastases within 9 months, emphasizing the importance of long-term follow-up for the early detection of recurrence.

Given the absence of clear treatment guidelines, further research is needed to explore the roles of radiation and chemotherapy in managing recurrent or metastatic LGFMS. Pathologists must remain vigilant to avoid misdiagnosing this deceptively benign-appearing tumor.

Although LGFMS is more commonly seen in younger adults, it should also be considered in elderly patients, as demonstrated in this case.