SHM Converge Scientific Abstract ePoster Gallery-Difficult Diagnosis of a Smarcb1/Ini1 Gene Deficient Lung Tumor With Brain Metastasis

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This case describes a 33-year-old man with a persistent cough after COVID infection whose lung findings were initially treated as pneumonia and possible fungal disease, but continued to worsen despite antibiotics and antifungal therapy. Imaging evolved from a right upper lobe patchy opacity to a 4.1 cm mass-like lesion with lymphadenopathy, and PET scan showed hypermetabolic lung and bone abnormalities. Multiple tissue samples from bronchoscopy and CT-guided lung biopsies were nondiagnostic, showing organizing pneumonia, atypical cells, necrosis, fibrosis, or reactive changes. An aspergillus antigen was initially positive on BAL, but cultures and later testing did not support infection.<br /><br />When the patient developed brain lesions, MRI revealed multiple ring-enhancing lesions in both cerebral hemispheres and the left cerebellum. Brain biopsy finally established the diagnosis of metastatic epithelioid sarcoma with complete loss of INI1 nuclear staining, indicating an SMARCB1/INI1-deficient tumor. He was referred for oncologic treatment with radiation and chemotherapy.<br /><br />The discussion emphasizes that SMARCB1/INI1-deficient tumors are rare, often occur in young men, and can present with varied morphologies and immunophenotypes. Diagnosis can be difficult because these tumors may grow rapidly and outstrip their blood supply, leaving necrotic or inflammatory tissue on repeated biopsies. In this case, only the brain biopsy contained viable tumor cells. The report highlights the importance of considering rare malignancies in patients with “refractory pneumonia,” persistent lung masses, atypical imaging findings, and disease progression despite appropriate treatment.

Asset Subtitle

Javeria Hayat

Meta Tag

Author List Elizabeth Jakubowski Bustamante, Javeria Hayat, Jeremy J. Gentile, Yajing Ji

Category Clinical Vignettes

Concept SMARCB1

Concept INI1 Loss

Concept SMARCB1-Deficient Tumor

Concept Tumor Suppressor

Concept Lung Tumor

Distinguished Non-Finalist

Presenter Organization Corewell Health/ MSU

Presenting Author Javeria Hayat

Track Adult

Keywords

epithelioid sarcoma

SMARCB1 deficiency

INI1 loss

metastatic brain lesions

lung mass

refractory pneumonia

organizing pneumonia

PET scan

ring-enhancing lesions

bone metastasis

SMARCB1

INI1 Loss

SMARCB1-Deficient Tumor

Tumor Suppressor

Lung Tumor