February 19, 2025

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

By Med-Challenger · 2 minute read

An 89-year-old man presents to you complaining of blood in his stool intermittently over the past 6 months. He reports an unintentional 20-kg weight loss during that time. He has not been to the doctor in more than 20 years and is taking no medications.

Vital signs are: temperature 37.1 °C, blood pressure 122/72 mm Hg, pulse 77 beats/minute, and respiratory rate 15 breaths/minute. He appears cachectic.

His complete blood count shows a white blood cell count of 11,000/mm3, his hemoglobin level is 11 mg/dL, and his platelet count is 133,000/mm3.

Prothrombin time (PT) and activated partial thromboplastin time (aPTT) are normal. D-dimer is elevated.

Which of the following is the most likely diagnosis?

acute disseminated intravascular coagulation (DIC)
heparin-induced thrombocytopenia (HIT)
thrombotic thrombocytopenic purpura (TTP)
malignancy and chronic disseminated intravascular coagulation (DIC)

The correct answer is:

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.

This question appears in Med-Challenger Family Nurse Practitioner Exam Review with CME

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