Differential Diagnosis for High Parietal Scalp Collection with Mild Anemia

Single Most Likely Diagnosis

• Chronic Subdural Hematoma: This condition is a common cause of scalp collection and mild anemia, especially in the elderly or after minor trauma. The high parietal location is typical for subdural hematomas due to the brain's anatomy and the way blood collects in this space.

Other Likely Diagnoses

• Epidural Hematoma: Although less common than subdural hematomas, epidural hematomas can also present with a scalp collection and signs of mild anemia. They are often associated with a more significant trauma and can have a more rapid progression.
• Subgaleal Hematoma: This condition involves bleeding into the space between the skull and the scalp, which can occur after trauma. It might present with a fluctuant mass on the scalp and could be associated with mild anemia if there's significant blood loss.
• Cephalohematoma: A collection of blood between the skull and its periosteum, typically occurring in newborns after delivery. However, it could be considered in adults with a history of trauma.

Do Not Miss Diagnoses

• Acute Subdural Hematoma: While chronic subdural hematomas are more likely to present with mild symptoms, an acute subdural hematoma is a medical emergency that requires immediate attention. It can present similarly but often with more severe symptoms and rapid deterioration.
• Meningioma with Hemorrhage: Although rare, a meningioma (a type of brain tumor) can bleed, leading to a collection of blood in the brain or scalp. This diagnosis is critical because it requires specific management, including possible surgery.
• Arteriovenous Malformation (AVM): An AVM can cause bleeding in the brain or scalp, leading to a collection of blood. Identifying an AVM is crucial due to its potential for significant morbidity and mortality if not treated properly.

Rare Diagnoses

• Hemangioma of the Scalp: A benign vascular tumor that could potentially bleed and cause a collection of blood in the scalp.
• Langerhans Cell Histiocytosis: A rare disorder that can cause lesions in various parts of the body, including the skull, potentially leading to a scalp collection.
• Metastatic Disease to the Scalp: Rarely, cancer can metastasize to the scalp, potentially causing a collection of blood or fluid.

Each of these diagnoses requires careful consideration of the patient's history, physical examination, and imaging studies (such as CT or MRI scans) for accurate diagnosis and appropriate management.