Hickam´s dictum: neurologic symptoms in Oncology

A 45-year-old woman was diagnosed with an stage III ovarian carcinoma.Five months later her neurological condition changed.

CLINICAL CASE: The patient started with a sensation of less sensitivity on her left side, nociceptive and tactil,  including her left facial area. She was able to move her arms and legs properly. An initial diagnosis of cerebral metastases or vascular problem was established.

CLINICAL EVOLUTION: A first CAT scan without contrast showed some nodularity on her right parietotemporal area. A MNR showed nodular images on the right temporoparietal area and cerebellum. The radiologist made clear that the aspect was related to embolus no metastases. A cardiac sonogram showed “vegetations” over the mitral valve. Blood culture was negative. A diagnosis of Non-infectious endocarditis  was established.

Non-infectious causes of endocarditis are classified as nonbacterial thrombotic endocarditis and are also known as marantic, Libmannn-Sacks, or verrucous endocarditis. Tipically involves a single valve. A review of 171 cases of thrombotic endocarditis found that 59% of the cases were in patients with underlying malignancy (Steiner I. Ces Patol).

COMMENTS: In an oncological patient starting with neurologic symptoms the first and more common diagnosis is CNS metastases. This was the situation in this patient, only the experience and advice from the radiologist changed the first orientation. Although a marantic endocarditis has been classically related with neoplasia is an uncommon diagnosis nowdays in clinical oncology. We can summarize this situation saying that patients can have all the disease that they wanted what is defined as the Hickam´s dictum. “Think about horses, don,t forget the zebras”.

Hickam’s dictum is a counterargument to the use of Occam’s razor in the medical profession. The principle is commonly stated: “Patients can have as many diseases as they damn well please”. The principle is attributed to John Hickam, MD. Hickam was a faculty member at Duke University in the 1950s, and was later chairman of medicine at Indiana University.(Wikipedia)

Katsouli A, Massad M. Current Issues in the Diagnosis and Management of Blood Culture-Negative Infective and Non-Infective Endocarditis. Ann Thorac Surg 2013; 5: 1467-74