No head trauma, so what's causing headaches?

A man in his 20s, previously in good health, went to a local emergency room for help after suffering from headaches for several months. He also said he was tired and sometimes had fevers and night sweats.

He hadn't suffered head trauma. He had used cocaine in the past, but denied intravenous drug use. He was sexually active, but his last HIV test a year ago was negative.

As part of his initial diagnostic work-up, a head CAT scan was ordered to exclude the possibility of a brain tumor or intracranial hemorrhage. Follow-up CAT scans of the neck, chest, abdomen, and pelvis showed some enlarged lymph nodes in his neck, sacrum, and pelvis. His blood work revealed elevated liver enzymes.

At this point, his medical team was most concerned about the possibility of lymphoma or some kind of infection. In a young person, lymphoma often can be present with symptoms such as headache, fevers, chills, and night sweats along with enlarged lymph nodes. But a lymph-node biopsy showed no evidence of this cancer.

Viral infections can certainly lead to the symptoms he described. Infectious mononucleosis, which is due to Epstein-Barr virus, can cause enlarged lymph nodes and elevated liver enzymes. It is a very common diagnosis in young people and usually resolves on its own. Given his history of drug abuse, viral hepatitis was another consideration. However, serological studies for Epstein-Barr virus and hepatitis A, B, and C were negative.

On further questioning, the man said his headaches were becoming continuous and intense. Results from his spinal tap were unremarkable. Next came an MRI of his head, which is superior to CAT scan for diagnosing subtle brain tumors.

The MRI showed a 1.3-centimeter lesion within the parietal bone (a skull bone) and surrounding soft-tissue swelling. The radiologist felt this could be due to an infection of the bone called osteomyelitis. But how could there be osteomyelitis in a young adult with no history of trauma or a predisposing condition such as diabetes or his being immunosuppressed?

Surgery was performed to remove the abnormal piece of parietal bone. A pathologist - a physician who examines blood samples, fluids, and tissues to make a diagnosis - then went to work.

Under the microscope, the pathologist could see in the bone what hadn't been apparent before: acute inflammation along with areas that showed longer-term changes, including fibrosis and scattered plasma cells. These features were consistent with osteomyelitis. 

Meanwhile, an infectious-disease physician ordered additional lab tests including HIV, which was negative again, and an RPR (Rapid Plasma Reagin), a screening test for syphilis. That result came back positive and was confirmed with a more sensitive test.

The pathologist also ordered an immunohistochemical stain for treponema pallidum, the bacterium that causes syphilis. This showed that the man's parietal bone was full of organisms consistent with a diagnosis of syphilis.

Syphilis is usually diagnosed in the primary phase as painless ulcers in the genital area or mouth, which eventually resolves after about 6 weeks. However, in some patients who do not seek medical attention, it can progress to secondary or tertiary forms. In secondary syphilis, most (but not all) patients have a different type of rash, typically on the hands and feet. In addition, they can have enlarged lymph nodes and fever. Tertiary syphilis is when the disease has progressed to involve the nervous system and other organs. At this stage, it can cause blindness, deafness, dementia, even death.

Fortunately, though the bacterium had spread to the skull, this patient's syphilis was detected in the secondary phase, before permanent damage was done. He was treated with a course of penicillin G, a narrow-spectrum antibiotic given by injection.

Walter Klein is a board certified pathologist at Main Line Health System and an active member of the Montgomery County Medical Society and the Pennsylvania Medical Society.

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