What is the best course of treatment for a 22-year-old female patient with a rare, aggressive soft tissue mass at the right thigh, showing hepatoid features, and suspected to be a neoplastic process, such as sarcoma, with reactive inguinal lymphadenopathy and suspicious signals in the right proximal femur?

Treatment Approach for Aggressive Soft Tissue Mass with Hepatoid Features

The patient should proceed with the planned wide surgical excision with negative margins followed by adjuvant radiotherapy (50-60 Gy), as this represents the standard treatment for high-grade, deep soft tissue sarcomas >5 cm, regardless of the unusual hepatoid histology. 1, 2

Surgical Management

Wide excision with negative margins is the definitive treatment and has already been appropriately performed. 1 The surgical approach should include:

• Minimum 1-cm margins for soft tissue sarcomas to reduce recurrence and metastasis risk 3
• Re-excision is mandatory if R1 (microscopically positive) or R2 (grossly positive) margins are identified on final pathology, provided adequate margins can be achieved without major morbidity 1
• Plastic reconstruction should be utilized as needed given the large tumor size (8 cm × 8 cm) and anticipated tissue defect 4
• The superficial lymphadenectomy performed was appropriate given the reactive inguinal lymphadenopathy, as certain sarcoma subtypes have higher nodal involvement risk 1

Adjuvant Radiotherapy

Postoperative radiotherapy is standard treatment for this patient based on tumor characteristics (large size >5 cm, deep location, suspected high-grade features): 1, 2

• Dose: 50-60 Gy in 1.8-2 Gy fractions, with potential boost up to 66 Gy depending on final margin status 1, 2
• Radiotherapy improves local control but not overall survival in soft tissue sarcomas 2
• Should be administered regardless of margin status given the tumor's high-risk features (>5 cm, deep, anterior thigh compartment) 2
• If margins are positive and re-excision is not feasible, radiotherapy becomes even more critical 1, 2

Addressing the Diagnostic Uncertainty

The hepatoid features create diagnostic complexity, but treatment should not be delayed pending definitive histologic classification: 1

• The negative hepatitis profile and alpha-fetoprotein argue against metastatic hepatocellular carcinoma 5
• Hepatoid adenocarcinomas are rare extrahepatic tumors with aggressive behavior, but the thigh location makes this diagnosis unlikely 5
• The MRI findings strongly suggest primary sarcoma (neoplastic process with suspicious femoral infiltration) 1
• Final histopathology from the wide excision specimen will provide definitive diagnosis and guide any additional therapy 1, 6

Systemic Therapy Considerations

Adjuvant chemotherapy is not standard for adult soft tissue sarcomas but may be considered as an option: 1

• High-risk features (high-grade, deep, >5 cm) make this patient a candidate for discussion of adjuvant chemotherapy 1
• Decision should be made after final pathology confirms histologic subtype and grade, as some subtypes are chemotherapy-insensitive 1
• If chemotherapy is used, it can be administered preoperatively or postoperatively with no difference in outcomes 1
• Regional hyperthermia combined with chemotherapy could be considered if tumor proves unresectable or recurs, though not indicated currently 7

Staging and Surveillance

Complete staging must be performed given the suspicious femoral signals and reactive lymphadenopathy: 1

• CT chest is mandatory to exclude pulmonary metastases prior to definitive treatment 1
• CT abdomen and pelvis should be included for high-grade lower extremity sarcomas 1
• MRI or CT of the right proximal femur to definitively assess for bone infiltration, as this would significantly alter prognosis and treatment 1
• Regional lymph node assessment by ultrasound or cross-sectional imaging is appropriate given the documented inguinal lymphadenopathy 1

Critical Pitfalls to Avoid

• Do not delay definitive treatment awaiting perfect histologic classification—the clinical and radiologic picture supports aggressive sarcoma management 1
• Do not omit radiotherapy based on achieving negative margins alone; tumor size >5 cm and deep location mandate adjuvant RT 2
• Do not perform inadequate re-excision if margins are positive—this is a critical opportunity to achieve local control 1, 6
• Ensure long-term surveillance as soft tissue sarcomas can recur years after treatment, with skin being a common metastatic site for superficial tumors 3

Management of Suspicious Femoral Involvement

If final pathology or imaging confirms femoral bone infiltration: 1

• This represents locally advanced disease requiring more aggressive multimodal therapy
• Preoperative chemotherapy and/or radiotherapy should be strongly considered if bone resection is required 1
• Orthopedic oncology consultation is essential for surgical planning if bone involvement is confirmed 1