Laboratory studies are not helpful in the diagnosis of the Zenker’s Diverticulum (ZD), whereas they are used for the upper esophageal webs associated with iron deficiency anemia. The laboratory tests are done to differentiate the ZD from Plummer- Vinson syndrome. Laboratory findings consistent with the diagnosis of Plummer-Vinson syndrome include the presence of iron deficiency anemia.

Laboratory studies are not helpful in the diagnosis of the ZD, whereas they are used for the upper esophageal webs associated with iron deficiency anemia. The laboratory tests is done to differentiate the ZD from Plummer- Vinson syndrome. Laboratory findings consistent with the diagnosis of Plummer-Vinson syndrome include presence of iron deficiency anemia:^{[1][2][3][4][5][6][7][8]}

Complete blood count (CBC)

Complete blood count (CBC) should be done in patients with Plummer-Vinson syndrome and will have the following findings:

• Low mean corpuscular volume (MCV <80 fl)
• Low mean corpuscular hemoglobin concentration (MCHC)
• Elevated platelet count (platelets > 450,000/µL)
• Normal or elevated white blood cell count

Iron studies

Iron studies should be done in patients with pallor, dysphagia or esophageal webs to confirm the diagnosis of Plummer-Vinson syndrome. The tests usually done for iron deficiency anemia are:

• Serum iron– Decreased in iron deficiency.
• Transferrin– Elevated in iron deficiency.
• Total iron binding capacity (TIBC)- Elevated in iron deficiency.
• Transferrin saturation– derived by dividing the serum iron by the TIBC. Decrease in iron deficiency.
• Ferritin– Indicator of body iron stores and is low in iron deficiency. However, ferritin also acts as an acute phase reactant and can be unreliable in inflammatory illness.

Peripheral smear

Peripheral smear may show:

• RBCs are microcytic and hypochromic
• Increased number of platelets
• Target cells (can be seen in any case of anemia)

Miscellaneous laboratory tests

• Stool testing (FOBT): It should be done in all men and postmenopausal women who present with iron deficiency anemia to rule out colonic polyps and malignancy.
• Bone marrow aspiration for stainable iron: This the most accurate test to determine iron deficiency. However, it is not routinely done, since other blood and iron studies are a reliable source to determine the presence of iron deficiency anemia.
• Blood lead levels