Differential Diagnosis for Extra-Axial Mass in Right Frontal Lobe
Given the history of large B cell lymphoma in remission and the incidental finding of an extra-axial mass in the right frontal lobe, the following differential diagnoses are considered:
Single Most Likely Diagnosis
- Secondary central nervous system lymphoma: This is a likely diagnosis given the patient's history of large B cell lymphoma. Lymphoma can recur in the central nervous system (CNS), and an extra-axial location is possible, although less common than intra-axial or leptomeningeal involvement.
Other Likely Diagnoses
- Meningioma: A common extra-axial tumor that could be found incidentally. Meningiomas are usually benign and can be asymptomatic, discovered during imaging for other reasons.
- Dural metastasis: Given the patient's history of cancer, metastasis to the dura from another primary site or from the lymphoma itself is a possibility, although less common than other metastatic sites.
- Epidural hematoma or abscess: Although less likely without a history of trauma or infection, these conditions can present as extra-axial masses and need to be considered due to their potential for serious complications.
Do Not Miss Diagnoses
- Subdural empyema: An infection that can present as an extra-axial mass and is a medical emergency requiring prompt treatment.
- Epidural abscess: Similar to subdural empyema, this is an infection that requires immediate attention to prevent serious neurological sequelae or death.
- Hemorrhagic metastasis: A metastatic lesion that has hemorrhaged can present acutely and require urgent intervention.
Rare Diagnoses
- Sarcomatous transformation of a meningioma: Extremely rare, but a possibility in patients with a history of radiation therapy or genetic predispositions.
- Primary CNS sarcoma: Very rare and could present as an extra-axial mass, but this would be an unusual initial presentation without other systemic symptoms.
- Langerhans cell histiocytosis: Can involve the CNS and present as an extra-axial mass, but this is more commonly seen in children and young adults without a history of lymphoma.