Chemotherapeutically Induced Cutaneous Tuberculosis after BCG Injection in a Patient with Pelvic Osteosarcoma

Tuberculosis (TB) is a serious infection afflicting a multitude of people worldwide. Recently, its prevalence has increased, particularly in patients with compromised immunity and other high-risk groups [1]. Although the incidence of skin involvement generally is low [1], cutaneous TB (CTB) can mimic a number of disorders, making diagnosis a challenge; and because intralesional bacilli often are sparse, isolation of organisms or histopathologic demonstration by acid-fast stain may be difficult. [2,3].

Bacillus Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis that typically is administered as a vaccine to stimulate the immune system when treating some early neoplasms or to guard against tuberculosis [4]. Occasionally, such vaccination results in CTB [5,6].

The authors herein describe a young man with osteosarcoma of the left hemipelvis who received intradermal BCG injection for immune stimulation prior surgery. In the course of neoadjuvant chemotherapy, he developed CTB.

Case Report

A 14-year-old Caucasian male was referred to our Department of Oncological Orthopaedics for evaluation of a tumor in the left hemipelvis. Symptoms had begun five months earlier, and radiographs obtained the following month showed a primitive bone tumor. By magnetic resonance and computed tomography (CT) scans, the lesion appeared to involve the iliac wing broadly to the sacroiliac joint, the roof of the acetabulum, and the entire range of gluteus muscles. Imaging was highly suggestive of osteosarcoma, so a needle biopsy was performed. Histopathology examination confirmed high-grade osteosarcoma; a total body CT scan was negative for distant metastasis.

In another hospital, an attempt to stimulate the patient's immunity with intradermal BCG injection proved ineffective, so he was referred to an oncologist. This physician was unaware of the prior BCG use. Neoadjuvant chemotherapy with high-dose methotrexate (12.0 g/kg), cisplatin, and doxorubicin was initiated per the Italian Sarcoma Group (ISG) OS1 protocol and was followed by the development of multiple ulcerated skin lesions. No antibiotic was administered. Therapy was continued by the oncologist despite the exacerbations of the skin condition with each course of chemotherapy, and the patient underwent surgery at our center.

Clinical inspection of the eruption disclosed ulcerated plaques in aggregates, involving the left deltoid area and the left inguinal fossa. The lesions generally were uniform, with an average diameter of 0.8 cm, and were red/pink with atrophic centers. Their borders were raised but ill-defined (Fig. 1). On biopsy, a granulomatous reaction compatible with tuberculous disease was observed (Fig. 2).

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FIG. 1.

Clinical view of skin lesions. (A) Inguinal region. (B) Deltoid area.

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FIG. 2.

Cutaneous biopsy showed poorly formed non-caseating granulomas with multinucleated giant cells in the upper dermis just below the epidermis. Ziehl-Neelsen stain revealed no bacilli. In deep dermis, cicatricial fibrosis was present. (Original magnification×10.)

Four weeks after cessation of chemotherapy, the patient was hospitalized for surgery. Treatment with rifampicin, ethambutol, and isoniazid was started after a presumptive diagnosis of CTB and given as prophylaxis at the start of anesthesia. The patient then underwent hemipelvic resection with provisional cement and screw reconstruction to reduce the risk of introducing infection. Definitive reconstruction was deferred to be done at one-year follow-up, provided the preliminary surgical results were not compromised by TB. Post-operative chemotherapy was still feasible, and no metastases were evident. A left inguinal lymph node sampled during surgery was positive for tuberculous lymphadenitis, showing the beginnings of scrofuloderma on histologic examination.