FIBROMYXOID SARCOMA IN RATTUS NORVEGICUS:

CASE REPORT

Abstract

Myxoid sarcoma encompasses malignant tumors that originate from myxoid tissues. Among these, Low-Grade Fibromyxoid Sarcoma (LGFM) is characterized by benign histopathological attributes, gradual progression, and yet, a heightened propensity for metastasis. Incidences of LGFM in human subjects tally at a minimum of 25 cases, predominantly manifesting within the deep intramuscular compartment, in the thigh and torso regions. However, occurrences have also been documented in anatomical sites like the retroperitoneum, mesentery, and renal capsule. In December of 2022, a juvenile male Wistar rat (Rattus norvegicus), aged 3 years, exhibited signs of distress, and exhibited a protruding mass, measuring 2.5 cm x 3 cm, in the dorsal aspect of the left pelvic limb. Following a diagnostic trajectory, surgical amputation was undertaken in January of 2023, unveiling a histopathological confirmation of myxoid sarcoma. After this, a growth, commencing at 2 cm, was observed on the left renal capsule in February 2023. This growth escalated to 6 cm by May 2023, mirroring the diagnostic outcome attributed to the previous limb lesion. This reported instance stands as the foremost documented occurrence of LGFM in the Wistar rat lineage on a global scale, constituting the second such manifestation observed in the realm of animal subjects.