Differential Diagnosis for Elevated Platelets and Ferritin with Normal Inflammatory Markers

Single Most Likely Diagnosis

• Reactive Thrombocytosis: This condition is characterized by an elevated platelet count in response to another underlying condition, such as iron deficiency anemia, which could also explain elevated ferritin levels as the body stores iron. The normal inflammatory markers suggest that there isn't an acute inflammatory process driving the elevation.

Other Likely Diagnoses

• Iron Deficiency Anemia: Often presents with elevated ferritin (as a marker of iron storage) and can lead to reactive thrombocytosis. The body's response to chronic blood loss or inadequate iron intake can result in these lab findings.
• Chronic Liver Disease: Conditions like cirrhosis can lead to hypersplenism, which in turn can cause thrombocytosis due to splenic sequestration of platelets. Elevated ferritin can be seen in liver disease due to increased iron storage or as an acute phase reactant, though the latter would typically be accompanied by other elevated inflammatory markers.
• Hemochromatosis: A genetic disorder leading to excessive iron absorption, which can cause elevated ferritin levels. Thrombocytosis might not be a direct result but could be seen in the context of liver disease secondary to hemochromatosis.

Do Not Miss Diagnoses

• Polycythemia Vera (PV): A myeloproliferative neoplasm that can present with thrombocytosis and elevated ferritin due to increased red blood cell mass and iron storage. Although inflammatory markers are typically normal, missing this diagnosis could lead to significant morbidity and mortality due to thrombotic complications.
• Hematologic Malignancies: Certain cancers like lymphoma or leukemia can present with elevated platelets and ferritin, especially if there's associated hemophagocytic lymphohistiocytosis (HLH) or significant marrow involvement. Normal inflammatory markers do not rule out these conditions entirely.

Rare Diagnoses

• Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC): A rare genetic disorder that can lead to elevated ferritin due to mutations in the FH gene. While not directly associated with thrombocytosis, the syndrome's complexity and the potential for renal cell carcinoma make it a rare but interesting consideration.
• Hyperferritinemia Cataract Syndrome: A rare genetic disorder characterized by elevated ferritin levels without iron overload, which could potentially be associated with thrombocytosis in some cases, though this would be an unusual presentation.