Clinical Scorecard: Case Study: Uncommon Thoracic SMARCA4-Deficient Undifferentiated Tumor with Metastasis to Extraocular Muscles Presenting as Diplopia

At a Glance

Key Highlights

• First reported case of SMARCA4-UT presenting as isolated metastasis to the inferior rectus muscle.
• Patient presented with binocular diplopia and ocular pain, with imaging revealing a nodular lesion.
• Histopathology confirmed SMARCA4-UT with complete loss of BRG1 expression.
• Systemic evaluation revealed primary lung lesion with mediastinal lymphadenopathy.
• Patient died shortly after chemotherapy and immunotherapy due to brain metastases.

Guideline-Based Recommendations

Diagnosis

• Consider SMARCA4-UT in differential diagnosis for atypical orbital lesions.
• Early tissue diagnosis is critical when inflammatory conditions do not respond to therapy.

Management

• Surgical excision of the tumor followed by systemic therapy may be necessary.

Monitoring & Follow-up

• Monitor for progression of disease and response to treatment, particularly in cases with atypical presentations.

Risks

• High risk of metastasis and aggressive disease course.

Patient & Prescribing Data

Patients with thoracic SMARCA4-UT, particularly those presenting with unusual metastatic sites.

Systemic steroid therapy may not be effective in managing symptoms related to SMARCA4-UT.

Clinical Best Practices

• Utilize imaging studies to assess for metastasis in patients with unexplained ocular symptoms.
• Involve multidisciplinary teams for comprehensive management of complex cases.

Related Resources & Content

• Le Loarer et al. 2015
• 2021 WHO Classification of Thoracic Tumors