Primary High-Grade Myxoid Liposarcoma of the Extremities: Prognostic Factors and Metastatic Pattern

Myxoid Liposarcoma Metastasizing to the Parotid Gland

Myxoid liposarcoma (MLPS) of the parotid gland is very rare, and only a few cases have been reported worldwide. It can be difficult to diagnose this disease when there is only a single lesion in the patient's body. A 56-year-old man was diagnosed with an MLPS in the left calf and was treated with wide resection. Two months after the surgery, a painless mass appeared in the man's left parotid gland area. Both fine-needle aspiration biopsy before surgery and intraoperative frozen sections suggested that the tumor was likely to be a pleomorphic adenoma. Both parotid ultrasound and CT indicated the same result. However, this mass was confirmed to be metastasis of MLPS through immunohistochemistry and multicolor fluorescence in situ hybridization. The authors report a case in which an MLPS metastasized to the parotid gland; this type of lesion is extremely rare and highly worthy of consideration because the authors misdiagnosed it.

Clinical impact of whole-body MRI in staging and surveillance of patients with myxoid liposarcoma: a 14-year single-centre retrospective study

OBJECTIVE

To assess the clinical impact of regular whole-body magnetic resonance imaging (WBMRI) surveillance in myxoid liposarcoma patients.

METHODS

This was a retrospective cohort study of myxoid liposarcoma patients who underwent at least one WBMRI at our institution between October 2006 and December 2020. The effect of WBMRI on clinical management, namely treatment modification or additional diagnostic investigations was studied. A standardised WBMRI surveillance protocol was instituted in 2015. We compared patient outcomes for the metastatic patients who had and had not received regular WBMRI surveillance and performed survival analysis for both subgroups.

RESULTS

Of the 56 patients (60.7% male, median age: 48.1 years) who underwent 345 WBMRI, 17 (30.3%) had metastases, and 168 WBMRI were performed in this group. The median imaging follow-up for the entire cohort was 35 months; the metastatic group had a median follow-up of 42 months. WBMRI changed the clinical management in 13 (76.5%) metastatic patients, with 33 instances of treatment modification. Thirty-five lesions were labelled 'indeterminate,' 16 (45.7%) had additional investigations/interventions, and 4 (11.4%) were confirmed to be metastatic. Twenty-one metastatic lesions were missed initially on WBMRI and confirmed on subsequent WBMRI, of which 5 (23.8%) were clinically significant. The 5-year survival since the detection of metastasis was better in the regular surveillance subgroup (85.7% vs. 45%), but this was not statistically significant (p = 0.068). Five patients (8.9%) developed their first metastasis more than 5 years after diagnosing the primary lesion.

CONCLUSION

Regular WBMRI surveillance of myxoid liposarcoma patients considerably impacts clinical management by frequently influencing treatment decisions.

CLINICAL RELEVANCE STATEMENT

WBMRI has been recently recommended as an imaging option for the staging and surveillance of myxoid liposarcoma patients. Our study highlights the impact of regular WBMRI surveillance on the clinical management of these patients and how it affects their survival.

Sensitivity, Specificity, and Predictive Values of Tru-Cut® Biopsy in Grading Primary Localized Myxoid Liposarcomas of the Extremities

(1) Background: Histological diagnosis and tumor grading are major prognostic and predictive factors in soft tissue sarcomas (STS), as they dictate the treatment strategies with a direct impact on patient survival. This study aims to investigate the grading accuracy, sensitivity, and specificity of Tru-Cut^® biopsy (TCB) in primary localized myxoid liposarcomas (MLs) of the extremities and its impact on patient prognosis. (2) Methods: Patients with ML undergoing TCB and a subsequent tumor resection between 2007 and 2021 were evaluated. Concordance between the preoperative assessment and definitive histology was calculated with a weighted Cohen's kappa coefficient. Sensitivity, specificity, and diagnostic accuracy were calculated. (3) Results: Of 144 biopsies, the histological grade concordance rate was 63% (Kappa 0.2819). Neoadjuvant chemotherapy and/or radiotherapy impacted concordance with a downgrading effect in high-grade tumors. Among forty patients not treated in neoadjuvant settings, the sensitivity of TCB was 57%, the specificity was 100%, and the overall predictive values of positive and negative TCB were 100% and 50%, respectively. Misdiagnosis did not impact overall survival. (4) Conclusions: TCB may underestimate ML grading due to tumor heterogeneity. Neoadjuvant ChT and/or radiotherapy are associated with pathological downgrading; however, discordance in diagnosis does not modify patient prognosis because systemic treatment decision-making also includes other variables.

A rare case report of a myxoid liposarcoma arising from the broad ligament

Myxoid liposarcoma (MLPS) is the second most prevalent subtype of liposarcoma. It is usually found in the deep tissues of the lower limbs and rarely in gynecologic tract. Herein we present the second case in the English literature of a primary MLPS arising from the broad ligament which was thought to be a borderline ovarian tumor. The aim is to discuss its clinical and pathological characteristics. A 42-year-old woman presented with pelvic pain for the last 6 months. Magnetic resonance imaging was not specific. She underwent a surgical resection of the tumor mass, and pathological examination confirmed the diagnosis of MLPS deriving from the broad ligament. She received radiotherapy and the patient is doing well at 3 months follow-up. The clinical aspects, pathological diagnosis, prognosis, and therapy approach of broad ligament MLPS are all poorly understood. Complete surgical resection with or without radiotherapy is the mainstay of treatment in located MLPS.