2025 – PAGE 289 – HEMATOLOGY & ONCOLOGY

(DOUBLE TAKE) FANCONI ANEMIA

Fanconi anemia is an APLASTIC anemia that is MACROCYTIC. Patients are usually older than 4 years of age. Look for multiple anomalies including short stature, café au lait spots, renal abnormalities, microcephaly, hypogonadism, and upper limb/hand anomalies. Treat Fanconi anemia with a bone marrow transplant.

MNEMONIC: Imagine you are a private investigator. You enter a mass murderer’s home and see A PLASTIC ceiling FAN. It has four ORANGE, PLASTIC (aplastic) blades that look like CONes. We’ll call them FAN CONES. Each of these ceiling FAN CONES has body parts hidden inside them. You look up right as HUGE BLOOD CELLS start to drip out of them. You find a stepladder, look inside the FAN CONES, and find a hidden GONAD, a SMALL HEAD, an ARM, and a HAND holding a mug of coffee. Remember, this is a CEILING fan. The Blackfan mnemonic is a standing plastic black fan.

NAME ALERT: The name alert is for FANCONI SYNDROME.

(DOUBLE TAKE) FANCONI SYNDROME 

Fanconi syndrome is the overall dysfunction of the proximal renal tubules, resulting in the loss of amino acids, proteins, electrolytes (sodium, potassium, bicarbonate, and phosphorus), and glucose. It has a number of etiologies, but the most common is cystinosis, a hereditary disease in which cystine accumulation damages the tubules. Look for polydipsia, polyuria, failure to thrive (FTT), and a ton of abnormal labs. The loss of bicarb results in a Type II Renal Tubular Acidosis (RTA), and thus a non-gap metabolic acidosis. The loss of phosphorus can present as RICKETS. Diagnose cystinosis by obtaining a leukocyte cystine level.

PEARLS: There are MANY possible diseases and points of confusion with these diseases. In Fanconi Syndrome, there is loss of sodium, and the serum sodium level is low to low-normal. In arginine vasopressin deficiency or resistance, there is a loss of WATER that can result in hypERnatremia if there’s no access to free water. Lastly, between Fanconi Anemia, Fanconi Syndrome, Diamond-Blackfan, and Shwachman-Diamond, there is tremendous room for confusion. Use mnemonics (PBR’s or your own) to keep them all straight!

NAME ALERT: The name alert is for FANCONI ANEMIA!

(DOUBLE TAKE) DIAMOND-BLACKFAN ANEMIA

DIAMOND-BLACKFAN ANEMIA is an anemia due to pure red cell aplasia. That means that unlike “aplastic anemias” which affect all cell lines (ie, pancytopenia), ONLY THE RED CELL LINE IS AFFECTED. Red cells are MACROCYTIC, anemia is typically severe, patients present around 3 months of age, and they may have TRIPHALANGEAL THUMBS and craniofacial anomalies. Look for low reticulocyte counts. If asked about treatment, use steroids chronically and transfuse for severe anemia.

• MNEMONIC: Imagine looking at a standing BLACK FAN with THREE GIANT PLASTIC BLADES. The blades are BLACK but are SHAPED LIKE RED CELLS.
  • KEY: BLACK FAN = Name, THREE = TRIphalangeal thumbs and 3 months old at presentation, GIANT = MACROCYTOSIS, PLASTIC = aPLASTIC because of the APLASIA, SHAPE = Reminder that this is a pure RED CELL aplasia. Remember that while there is “aplasia,” this is not a true “aplastic anemia” because those include pancytopenia.

• PEARL: If you see a patient with anemia and icterus or hyperbilirubinemia suggesting hemolysis, it is NOT Diamond-Blackfan Anemia. Since there is a red cell aplasia, the anemia is from a lack of production, NOT from hemolysis.
• NAME ALERT: The name alert is for SHWACHMAN-DIAMOND SYNDROME and Fanconi Anemia.