Abstract：
UNASSIGNED: Myoepithelial tumors are under-recognized neoplasms that could be difficult to identify due to their rarity and limited comprehension. Their diverse morphology, varied cytologic features and heterogenous immunohistochemical characteristics create a significant diagnostic challenge.
METHODS: We report the case of a 72-year-old-male patient who received conservative treatment during one year for a popliteal mass on the right knee that showed synovial hyperplasia (benign findings) at initial open tissue biopsy. New symptoms of popliteal area enlargement and discomfort required a second incisional biopsy to reach the diagnosis of a soft tissue myoepithelial tumor through tissue analysis and immunohistochemical staining.
UNASSIGNED: The myoepithelial tumors represent a medical dilemma due to their heterogenic features requiring high level of suspicion and adequate immunohistochemical markers for their diagnosis.
CONCLUSIONS: Orthopaedic surgeons should be aware of the atypical presentation of these rare neoplasms to provide an early diagnosis and adequate management.
METHODS: We report the case of a 72-year-old-male patient who received conservative treatment during one year for a popliteal mass on the right knee that showed synovial hyperplasia (benign findings) at initial open tissue biopsy. New symptoms of popliteal area enlargement and discomfort required a second incisional biopsy to reach the diagnosis of a soft tissue myoepithelial tumor through tissue analysis and immunohistochemical staining.
UNASSIGNED: The myoepithelial tumors represent a medical dilemma due to their heterogenic features requiring high level of suspicion and adequate immunohistochemical markers for their diagnosis.
CONCLUSIONS: Orthopaedic surgeons should be aware of the atypical presentation of these rare neoplasms to provide an early diagnosis and adequate management.
摘要：
未经证实：肌上皮肿瘤是认识不足的肿瘤，由于其稀有性和理解有限，可能难以鉴别。它们不同的形态，不同的细胞学特征和异质性的免疫组织化学特征产生了重大的诊断挑战。
方法：我们报告了一例72岁男性患者，该患者在一年内接受了保守治疗，因为右膝上的pop肿块在最初的开放组织活检中显示滑膜增生（良性发现）。pop区增大和不适的新症状需要进行第二次切开活检，以通过组织分析和免疫组织化学染色来诊断软组织肌上皮肿瘤。
UNASSIGNED：由于其异源性特征，需要高度怀疑和足够的免疫组织化学标记来诊断，肌上皮肿瘤代表了医学上的困境。
结论：骨科医生应该意识到这些罕见肿瘤的非典型表现，以提供早期诊断和适当的治疗。
方法：我们报告了一例72岁男性患者，该患者在一年内接受了保守治疗，因为右膝上的pop肿块在最初的开放组织活检中显示滑膜增生（良性发现）。pop区增大和不适的新症状需要进行第二次切开活检，以通过组织分析和免疫组织化学染色来诊断软组织肌上皮肿瘤。
UNASSIGNED：由于其异源性特征，需要高度怀疑和足够的免疫组织化学标记来诊断，肌上皮肿瘤代表了医学上的困境。
结论：骨科医生应该意识到这些罕见肿瘤的非典型表现，以提供早期诊断和适当的治疗。
