When a 57-year-old man walks through the doors of the Dublin emergency room, doctors do not expect to discover an almost unprecedented clinical case. For a week, the man has been suffering from a red, swollen, painful organ. But what seemed to be a dermatological banality ultimately turned out to be one of the most atypical locations of tuberculosis: penile tuberculosis in the context of miliary tuberculosis, a disseminated form of the disease.
A very exposed and severely immunocompromised patient
From the first minutes, however, doctors understand that the patient presents several major risk factors. Fifteen years earlier, he had received a kidney transplant and remained treated with immunosuppressants. These essential medications limit rejection of the organ, but profoundly weaken its immune system, leaving the door open to opportunistic infections such as tuberculosis.
His professional environment adds another piece to the puzzle. Born on a farm, the man has worked for decades as a butcher, handling livestock carcasses and game on a daily basis. Passionate about hunting, he skins the animals himself. This repeated exposure could put him in contact with
Mycobacterium bovisa bovine cousin of human tuberculosis and sometimes transmissible to humans.
Ineffective antibiotic treatment and accumulating symptoms
Faced with inflammation of the penis, the first avenue seems logical: a bacterial skin infection. A standard antibiotic is therefore prescribed, until the edema increases, so does the pain.
As doctors question the patient, a bigger picture emerges. For months, the man has lived with fever, heavy night sweats, loss of appetite and significant weight loss. Systemic signs which point to a much deeper disease than a simple local infection.
A series of chest, abdominal and pelvic scans are performed. Radiologists discovered lungs literally studded with tiny nodules (a typical appearance of miliary tuberculosis). Samples taken from the respiratory tract and from the penile lesion show the presence of mycobacteria. Tuberculosis is confirmed even in the penis.
An unlikely case, but not impossible
“Yes, tuberculosis of the penis is possible” replies our medical director, Dr. Gérald Kierzek. “This remains an exceptionally rare location, but in a kidney transplant patient taking immunosuppressants, the risk of extrapulmonary or disseminated tuberculosis increases markedly.
According to him, several cases can give this astonishing result.
- An infection directly in the penis (primary form); “This remains exceptional, but possible through sexual contact with a person with tuberculous genital lesions, via contaminated linen or equipment, or in very rare ritual contexts (circumcision with infected tools)”;
- Secondary damage, the most likely here, is also possible. In miliary tuberculosis, bacteria circulate in the blood or lymph. They can then reach almost any organ, including the genital tissues.
“In immunocompromised people such as transplant recipients, this dissemination is common.”
Moreover, among solid organ transplant recipients, tuberculosis is 20 to 70 times more frequent than in the general population.
“In this context, the appearance of a penile lesion secondary to tuberculosis bacteremia is entirely plausible.”
Once the correct diagnosis was made, the patient was placed on quadruple anti-tuberculosis therapy, a standard treatment, but complex in transplant recipients because it interacts strongly with immunosuppressants. But after ten months of treatment, the improvement is clear: the lesions have healed and the infection is under control.
An origin that is not completely elucidated
Doctors remain cautious: in this specific case, it is impossible to determine with certainty how the bacteria entered the body. Whether it is an old mycobacterium dormant in the transplanted kidney, reactivated by immunosuppression or auto-inoculation, after contact with infected animal carcasses, the mystery remains.
But for Dr Gérald Kierzek, this story perfectly illustrates the complexity of tuberculosis in immunocompromised patients:
“In a kidney transplant recipient taking immunosuppressants with an ulcerated or nodular lesion of the penis, it is absolutely necessary to think about tuberculosis. The diagnosis is made by biopsy, AFB search and imaging examination, before starting an appropriate quadruple therapy.”
Fortunately, this type of case remains rare…