Case 1 A 24‐year‐old man presented with asymptomatic, gradually progressive plaques and nodules over the right knee extending to the thigh in a linear pattern of 3 months' duration. A year previously, he had been diagnosed with tuberculosis of the spine and had been advised to take antitubercular treatment; however, he chose to stop treatment on his own after 4 months of therapy as his spinal condition improved with a marked decrease in pain. There was no history of fever, systemic complaints, or any spinal or knee injury preceding the disease. His mother had received treatment for pulmonary tuberculosis 4 years previously.
Dermatologic examination revealed well‐defined, brownish papules, plaques, and nodules of variable sizes, ranging from 3 cm to 6 cm, present over the right knee and front of the thigh in a linear pattern. The lesions were soft in consistency with ‘‘apple‐jelly’' nodules and the surrounding skin showed atrophic scarring (Fig. 1).
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Plaques and nodules in a sporotrichoid distribution over the right lower limb (Case 1)
All the hematologic and biochemical investigations were normal except for an elevated erythrocyte sedimentation rate (ESR) (48 mm/1 h). Venereal disease research laboratory (VDRL) test, enzyme‐linked immunoabsorbent assay (ELISA) for human immunodeficiency virus (HIV), and sputum examination for acid‐fast bacilli (AFB) were negative. Mantoux test with 1 tuberculin unit (TU) of purified protein derivative‐standard (PPD‐S) showed an induration of 25 × 20 mm. Blood culture and culture of the tissue homogenate for Mycobacterium tuberculosis, atypical mycobacteria, and fungal organisms revealed no growth. Slit skin smears from the plaque showed only lymphocytes and a few neutrophils. Immunoenzymatic test (ELISA) for antimycobacterial immunoglobulin M (IgM) antibody against the A 60 antigen complex was strongly positive (> 1 : 200 U). Histopathologic examination revealed a hypertrophic epidermis with noncaseating tuberculoid granulomas consisting of lymphohistiocytes, epithelioid cells, and Langhans' giant cells in the papillary and upper reticular dermis (Fig. 2a,b). No AFB were detected. Polymerase chain reaction (PCR) and guinea pig inoculation could not be performed due to a lack of facilities.
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(a) Photomicrograph showing noncaseous tuberculoid granulomas in the papillary dermis (hematoxylin and eosin, × 40); (b) photomicrograph showing Langhans' giant cells (arrow) in the dense granuloma
Skiagram of the chest was normal, although X‐ray of the lumbosacral spine revealed bony destruction of the sacral foramina. A magnetic resonance image (MRI) in the sagittal and axial plane was suggestive of caries of the fifth lumbar and sacral vertebrae with a large presacral and anterior epidural collection (Fig. 3). Computed tomography (CT) scan‐guided abscess drainage of the sacral region was performed and microscopic examination of the fluid revealed lymphocytes, polymorphs, macrophages, and a few AFB in a necrotic background.
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Magnetic resonance image in the sagittal plane: caries ...