Undifferentiated embryonal sarcoma of the liver in pediatric patients: a single-institution retrospective case series

Abstract

Background: Undifferentiated embryonal sarcoma of the liver (UESL) is a rare and highly aggressive malignancy predominantly affecting children and adolescents. Managing UESL is particularly intricate due to its aggressive nature and the limited array of treatment options available. This study is dedicated to elucidating the efficacy of a multimodal therapeutic strategy in the successful management of UESL.

Case description: Four pediatric patients (two males, two females; aged 6-11 years) diagnosed with UESL were treated at the Children's Hospital of Nanjing Medical University between November 2019 and June 2023. Surgical resection with lymph node dissection achieved complete primary tumor eradication. Adjuvant chemotherapy tailored to each patient's needs was followed by localized radiation therapy. After 9-42 months of follow-up, one patient who did not undergo immediate radiotherapy experienced a relapse. Following a second operation coupled with radiotherapy, the patient achieved complete remission, and mirroring the status of the other three patients who are now presently in remission. The overall cohort exhibited commendable tolerance to the treatment regimen, with manageable chemotherapy-related toxicities.

Conclusions: This case series suggests that implementing a standardized protocol of resection, followed by adjuvant chemotherapy and radiation, can lead to favorable outcomes in pediatric patients diagnosed with UESL. Nevertheless, the need for comprehensive large-scale studies is imperative to substantiate the effectiveness of this approach.

Keywords: Undifferentiated embryonal sarcoma of the liver (UESL); case series; multimodal treatment; radiation therapy.

Figure 1

Abdominal MRI images of UESL (Case 1). (A) T1-weighted image of liver tumor lesions shows low signal. (B) T2-weighted image of the lesion with high signal, within which wall nodules and numerous segregations are seen. (C) Scattered streaks within the lesion seen in the arterial phase, with mild enhancement. MRI, magnetic resonance imaging; UESL, undifferentiated embryonal sarcoma of the liver.

Figure 2

The pathological features of UESL (Case 1). (A) Macroscopic examination revealed a large cystic mass containing a significant amount of dark red blood clots in the lumen. (B,C) Microscopic analysis demonstrated a tumor comprised of actively dividing spindle cells, astrocytes, and multinucleated giant cells. The tumor cells exhibited marked heterogeneity, accompanied by laxity of pericytes and focal areas of hemorrhage and necrosis. Additionally, remnants of bile ducts were observed within the tumor (B, HE ×100; C, HE ×400). UESL, undifferentiated embryonal sarcoma of the liver; HE, hematoxylin-eosin staining.

Figure 3

Immunohistochemical analysis of UESL is presented (Case 1). The immunohistochemical staining of tumor cells reveals a widespread positive staining for vimentin (A), CD68 (B), and a focal positive staining for desmin (C), while it demonstrates a negative staining for SMA (D), MyoD1 (E), and CK (F). UESL, undifferentiated embryonal sarcoma of the liver; SMA, spinal muscular atrophy; MyoD1, myogenic differentiation 1; CK, creatine kinase.