Chloromas are rare, solid tumors composed of immature white blood cells, primarily associated with acute myeloid leukemia (AML). These masses signal an underlying systemic disease rather than being independent primary tumors.
Understanding Chloromas
Chloromas are characterized by collections of myeloblasts. They can emerge before, during, or after an AML diagnosis, sometimes even signaling a relapse.
Historically known as granulocytic sarcomas, the term “chloroma” refers to their occasional green color. This hue stems from high levels of the enzyme myeloperoxidase (MPO) within the tumor cells. However, up to 70% of these tumors may appear white, gray, or brown, depending on the enzyme’s concentration and oxidation state.
Where Chloromas Appear
Chloromas can develop in nearly any organ or tissue throughout the body, with symptoms varying greatly depending on their location and size. Common sites include bones, particularly the skull, spine, and ribs, where they might cause localized pain or swelling. The skin is another frequent site, presenting as raised, non-tender nodules or plaques, a condition sometimes called leukemia cutis.
When chloromas affect the central nervous system, they can lead to neurological deficits like headaches, seizures, or nerve palsies if they compress nerves or the spinal cord. Involvement in the orbit of the eye can cause proptosis, an outward bulging of the eye. Less common locations include the gastrointestinal tract, lymph nodes, breasts, and gonads, each potentially causing site-specific symptoms such as abdominal pain or swelling.
Diagnosing Chloromas
Diagnosis often begins with a physician suspecting a chloroma based on symptoms and physical examination. However, because symptoms can be non-specific and mimic other conditions, definitive diagnosis requires specific tests.
Imaging techniques, such as computed tomography (CT) scans, magnetic resonance imaging (MRI), and positron emission tomography (PET) scans, help visualize the tumor’s size and extent. A tissue biopsy is essential for a conclusive diagnosis, where a sample of the mass is removed and examined under a microscope.
Pathologists analyze the tissue for myeloblasts and use immunohistochemistry to confirm the diagnosis and distinguish it from other tumor types. Concurrent blood tests and a bone marrow biopsy are often performed to check for underlying leukemia, even if not immediately evident.
Managing Chloromas
Management of chloromas is primarily integrated with the treatment of the underlying acute myeloid leukemia (AML) or other associated blood disorders. Systemic chemotherapy, involving powerful drugs that kill cancer cells, is the cornerstone of treatment.
Radiation therapy is often used for localized chloromas, especially those causing pain, neurological compression, or other significant symptoms. It can be administered as a primary treatment for the mass or in conjunction with chemotherapy to enhance local control.
Surgical intervention is generally not the primary treatment but may be considered for diagnostic biopsy or to relieve severe compression on vital structures. Advanced treatment options for AML, such as targeted therapies and hematopoietic stem cell transplantation, also impact chloromas by addressing the systemic disease. The prognosis for patients with chloromas largely depends on the prognosis of their underlying leukemia, and treatment response is continuously monitored.