extramedulláris

Extramedulláris refers to something located outside the medulla. The medulla is a part of an organ or structure, most commonly referring to the medulla oblongata, the lowest part of the brainstem, or the renal medulla, the inner part of the kidney. Therefore, extramedullary findings or processes occur beyond these specific central regions.

In a neurological context, extramedullary tumors, for instance, are neoplasms that arise outside the spinal cord itself, such as meningiomas or schwannomas, which can compress the spinal cord. This is in contrast to intramedullary tumors, which grow within the substance of the spinal cord. Similarly, extramedullary hematopoiesis is the production of blood cells outside the bone marrow, which is the primary site of hematopoiesis. This can occur in organs like the spleen, liver, or lymph nodes, and is often seen in certain hematological conditions.

In urology, extramedullary masses in the kidney would be lesions found in the renal cortex or outside the renal parenchyma altogether, as opposed to those originating within the medulla. The term emphasizes the spatial relationship of a pathological or physiological process relative to a specific medullary structure. Understanding whether a condition is intramedullary or extramedullary is crucial for diagnosis and treatment planning.