Hematologic disorders with production of hemoglobin F:
(1) erythroleukemia
(2) juvenile chronic myeloid leukemia
(3) malignant lymphoma, including Burkitt's lymphoma
(4) myelodysplastic syndrome
(5) multiple myeloma
Non-hematologic disorders with production of hemoglobin F:
(1) germ cell tumors (embryonal carcinoma, teratoma)
(2) colorectal carcinoma
(3) transitional cell carcinoma
(4) lung cancer
(5) breast cancer
(6) endometrial cancer
(7) brain tumor
Features:
(1) unexplained presence of increased hemoglobin F (including increase from previously documented level)
(2) decrease in hemoglobin F on successful therapy of the triggering neoplasm
(3) exclusion of drugs or other causes for an elevated hemoglobin F
One mechanism for the production of hemoglobin F is extramedullary hematopoiesis with hemoglobin F being produced in red blood cell precursors. These can be demonstrated using immunohistochemistry.
