Delayed Diagnosis of Scrofuloderma Misdiagnosed as a Bacterial Abscess Fig. 1. Erythematous suppurative plaques with central ulceration on the surface of her neck. Fig. 2. Epithelioid cell granulomas with inflammatory cell infiltrations in the dermis (H&E, ×100), Inset: Acid-fast bacilli on Ziehl-Neelsen staining (H&E, ×1,000). treated with antibiotics at two local clinics and by an ENT doctor at our hospital. Earlier therapeutic attempts with antibiotics (Banan; Meiact; cefditoren pivoxil) were unsuccessful and the lesion was sometimes reduced but never had disappeared entirely. Further investigations such as a computed tomography (CT) study of the neck, and fine needle aspiration cytology (FNAC) were done by the ENT doctor of our hospital to rule out malignancy. Also, she was referred to our clinic for the evaluation of chronic dermatologic disease. At that time, the characteristic appearance of her lesion allowed us to discern cutaneous tuberculosis, especially scrofuloderma and further workups including skin biopsy, polymerase chain reaction (PCR) for Mycobacterium tuberculosis, cul- tures (bacterial, fungal, and mycobacterial), and chest X-ray were carried out. Histological examinations revealed epithelioid cell granu- lomas with inflammatory cell infiltrates in the dermis. Fig. 3. Positive results on polymerase chain reaction for the detection of Mycobacterium tuberculosis. Lane M: molecular weight marker, Lane PC: positive control, Lane NC: negative control, Lane 3: patient’s sample. Ziehl-Neelsen stain demonstrated acid-fast bacilli (Fig. 2). Cultures from the skin biopsy showed growth of Myco- bacterium tuberculosis after 8 weeks. Fungal and standard bacterial cultures from the skin biopsy were negative. A PCR study for the detection of Mycobacterium tuberculosis was conducted on a biopsy specimen and turned out positive (Fig. 3). However, FNAC from the skin lesions on the neck showed only neutrophils and fibrin exudates. A radiograph of the chest revealed 1 cm, small, calcified nodules on the right upper pulmonary lobe, and pulmo- nary tuberculosis was suspected (Fig. 4A). CT of the neck, which demonstrated peripheral enhancing low density lesions with extension to the cutaneous area, was found and ruled out an abscess or malignancy (Fig. 4B). Based on clinical examinations, staining for acid-fast bacilli, and positive PCR findings, a rapid diagnosis of scrofulo- derma was made. The patient was quickly started on an anti-tubercular treatment regimen that included isoniazid, rifampicin, ethambutol and pyrazinamide. The cutaneous lesion regressed in a slow but complete fashion. Her treatment with anti-tuberculosis therapy was successful and the ulcer healed after 18 months. DISCUSSION Cutaneous tuberculosis remains a rare infection, with an incidence of 3.5% reported among patients with organ tuberculosis5. Among them, scrofuloderma is a common form of cutaneous tuberculosis; it is seen in many deve- loping countries and in some European countries5,6. It is Vol. 24, No. 1, 2012 71