An 89-year-old man complains of blood in his stool intermittently

malignancy and chronic disseminated intravascular coagulation (DIC)

Educational Objective:

Diagnose chronic disseminated intravascular coagulation.

Key Point:

Chronic DIC is often secondary to malignancy, and patients with chronic DIC often have an elevated D-dimer, mild thrombocytopenia, and mildly abnormal or normal PT/aPTT times.

Explanation:

This patient has a clinical presentation and laboratory findings most consistent with malignancy with chronic DIC. His report of blood in his stools and associated unintentional weight loss are suspicious for an underlying malignancy, which can cause chronic DIC.

HIT would be unlikely in this patient who has not seen a doctor in many years, because HIT requires exposure to heparin. In addition, patients with HIT do not generally present with coagulation abnormalities (eg, elevated D-dimer) unless they have concurrent thromboembolism. Patients with TTP are generally acutely ill, and they would also not be expected to have a positive D-dimer. Patients with acute DIC would be expected to have more pronounced thrombocytopenia as well as substantial prolongation of PT and aPTT.

References:

Arruda V, High K. Coagulation disorders. In: Jameson J, et al, eds. Harrison’s Principles of Internal Medicine. 20th ed., 2018:834-838.

Toh CH, Alhamdi Y, Abrams ST. Current pathological and laboratory considerations in the diagnosis of disseminated intravascular coagulation [Erratum appears in Ann Lab Med. 2017;37:95]. Ann Lab Med. 2016;36:505-512.