Tubercular cold abscess at an unusual site mimicking a pyogenic abscess
1 Faculty of Medicine, Jawaharlal Nehru Medical College, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
2 University Health Service, Aligarh Muslim University, Aligarh, Uttar Pradesh, India
International Medical School,
Management & Science University, Shah Alam, Malaysia
Tuberculosis affects much of the world’s population, and 1 - 5%
of all cases are musculoskeletal. Tuberculosis of the soft
tissues secondary to underlying bone involvement is not
uncommon, but selective tissue involvement without bony
abnormality is rare. We present a case in which two tubercular
abscesses presented at an unusual site with no underlying bony
involvement, simulating a pyogenic abscess.
S Afr J CH 2013;7(2):77-78.
Tuberculosis affects a significant percentage of the world’s
population, and musculoskeletal tuberculosis constitutes 1 - 5%
of all cases.1
Tuberculosis of the soft tissues, in the
form of conditions such as tubercular bursitis, tubercular
synovitis and tubercular spondylitis secondary to underlying
bone involvement, is not uncommon.[2- 3] Selective tissue
involvement without bony abnormality, however, is rare. We
hereby present a case in which two tubercular abscesses
presented at an unusual site with no underlying bony
involvement, simulating a pyogenic abscess.
A 2-year-old boy presented with complaints of fever, cough and progressively increasing swellings on both lower limbs for the past 1.5 months. He also had decreased appetite and poor weight gain. There was no history of contact with a case of tuberculosis. On examination two discrete swellings were noted, one measuring 3×4 cm and situated on the dorsal aspect of the right foot just below the lateral malleolus (Fig. 1) and the other, measuring 5×6 cm, on the left leg just above left lateral malleolus, with no evidence of inflammation (Fig. 2). The swellings were non-tender, mobile, superficial and without any discharging sinus.
Fig. 1. A 2-year-old boy with a swelling measuring 3×4 cm on the dorsal aspect of the right foot just below the lateral malleolus.
Fig. 2. The same patient, with a swelling measuring 5×6 cm on the left leg just above the left lateral malleolus.
A full blood count showed lymphocytosis, the Mantoux test was
strongly positive with cross-sectional (horizontal) induration
of 16 mm, the chest radiograph showed some hilar prominence, and
fine-needle aspiration cytology (FNAC) showed acid-fast bacilli
on Ziehl-Neelsen staining (Fig. 3). Radiographs showed no
evidence of underlying osteomyelitis.
Extrapulmonary tuberculosis accounts for up to one-third of all cases. Children have a higher predisposition to the development of extrapulmonary tuberculosis.4 Tuberculosis can involve the soft tissues by extension from bone, synovial lining of joints or tendon sheaths; by direct inoculation; and, rarely, by haematogenous dissemination.5 However, selective primary soft-tissue involvement without osseous involvement is rare. It probably occurs via haematogenous spread from an occult primary focus elsewhere. Magnetic resonance imaging (MRI), especially with gadolinium enhancement, is very helpful in the diagnosis of soft-tissue abscesses, but tissue diagnosis is confirmatory. Tuberculous polymyositis has characteristic features of a well-demarcated abscess with rim enhancement on MRI.6 However, needle aspiration and examination is usually sufficient. Our patient’s family could not afford MRI, but FNAC was suggestive of tuberculosis without clearly identifying the tissue localisation. Tuberculosis should be considered in the differential diagnosis of any unexplained soft-tissue swelling in people born in tuberculosis-endemic areas.
Consent. Written informed consent was obtained from the patient’s guardian for publication of this case report and the accompanying images. A copy of the written consent is available from the authors.
Author contributions. SA and AA collected the data, and analysed and interpreted the literature and put together the case report, DIK was involved in collecting pictures and reviewing articles, SA, AA, TN and MS drafted and proof-read the manuscript, and SA, DIK and TN gave final approval of the version to be published. All authors read and approved the final manuscript.
1. Weir MR, Thornton GF. Extrapulmonary tuberculosis: Experience of a community hospital and review of the literature. Am J Med 1985;79(4):467-478. [http://dx.doi.org/10.1016/0002-9343 (85)90034-8]
2. Abdelwahab IF, Kenan S, Hermann G, et al. Tuberculous peroneal tenosynovitis: A case report. J Bone Joint Surg Am 1993;75(11):1687-1690.
3. Goldberg I, Avidor I. Isolated tuberculous tenosynovitis of the achilles tendon: A case report. Clin Orthop Relat Res 1985;194:185-188. [http://dx.doi.org/10.1097/00003086-198504000-00027]
4. Tappeiner G, Wolff K. Tuberculosis and other mycobacterial infections. In: Fitzpatrick TB, Freedberg IM, Eisen AZ, Wolff K, eds. Dermatology in General Medicine. New York: McGraw-Hill, 1999:2274-2292.
5. Derkash RS, Makley JT. Isolated tuberculosis of the triceps muscle: Case report. J Bone Joint Surg Am 1979;61(6A):948.
6. Kim JY, Park YH, Choi KH, et al. MRI of tuberculous pyomyositis. J Comput Assist Tomogr 1999;23(3):454-457. [http://dx.doi.org/10.1097/00004728-199905000-00023]
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