A Case of Isolated Primary Muscular Tuberculosis of the Gluteal Region

Abstract

Muscular tuberculosis is one of the rare types of tuberculosis, with an incidence of around 0.01%–1%. Muscular tuberculosis can be primary or secondary. Primary muscular tuberculosis can be due to direct trauma or direct inoculation of tuberculous bacilli. Secondary muscular tuberculosis is a part of disseminated tuberculosis. Our patient was initially diagnosed with pyogenic abscess and treated, but the patient failed to respond and later presented with multiple abscess cavity. Biopsy from the cavity wall proved as muscular tuberculosis and the patient responded well to anti-tuberculous treatment. Muscular tuberculosis must be considered one of the differential diagnoses for the patient with multiple gluteal discharging sinuses. The best investigation to confirm muscular tuberculosis is histopathological confirmation of granuloma.

INTRODUCTION

Muscular tuberculosis can involve any muscle. Muscular tuberculosis is mostly present as muscle mass, myositis, or deep abscess. According to the literature, thigh muscle, calf muscle, chest wall muscle, the psoas muscle is the most common muscle involved in muscular tuberculosis. Gluteal muscle and forehead muscles are rarely reported in the literature. Our case presented with multiple discharging sinuses in the gluteal region.

CASE REPORT

A 45-year-old female patient presented with a complaint of pain and swelling over the right gluteal region for a 1-month duration. There was no history of chronic cough with expectoration. There was no history of loss of appetite or loss of weight. The patient denied a previous history of tuberculosis or a history of exposure to tuberculosis. On examination, the patient was well built and nourished. The systemic examination was normal. Local examination showed a single abscess cavity with local features of inflammation. The patient underwent incision and drainage of the abscess cavity and the patient did not respond well.

Blood investigations such as complete blood count, renal function test, and liver function were normal. Ultrasound examination showed a few small hypoechoic lesions present in the right gluteal region. Fine-needle aspiration of lesions was inconclusive. Chest X-ray showed a normal study. Mantoux test revealed no induration after 72 h. Computed tomography of the chest and abdomen showed a normal study.

She was treated initially for a pyogenic gluteal abscess due to the presence of a single abscess cavity. The patient did not respond to treatment and in due course, the patient developed multiple gluteal sinuses [Figure 1]. Later, the patient underwent abscess draining with excision biopsy of the sinus tract [Figures 2 and 3]. Postoperative histopathology examination showed features of muscular tuberculosis such as giant cells and granuloma [Figure 4]. The patient was started on antituberculous treatment (isoniazid, rifampicin, ethambutol, and pyrazinamide). The patient showed a good response following antituberculous treatment. Postexcision biopsy, the patient recovered well and has been on follow-up for more than 2 years without any recurrence.

Figure 1: Multiple discharging gluteal sinuses

Figure 2: Intraoperative picture shows sinus tract originating from the muscle

Figure 3: Postexcision biopsy of gluteal sinus tract with muscle

Figure 4: Postoperative biopsy shows granulomas with epithelioid giant cells and areas of caseation necrosis

DISCUSSION

Muscular tuberculosis is one of the rare types of tuberculosis, with an incidence of around 1%.^[1] Primary muscular tuberculosis is rare compared to secondary muscular tuberculosis. The location of muscular tuberculosis varies from the lower limb to the upper limb. Most of the studies show muscular tuberculosis more commonly affect the lower limb compared to other locations. Muscular tuberculosis is mostly present as local muscle mass, myositis, muscular abscess, nodule, and painful mass. Most muscular tuberculosis does not have systemic manifestations such as fever, malaise, loss of appetite, and loss of weight.^[2,3]

Zeng etal.^[4] showed muscular tuberculosis sometimes misdiagnosed as sarcoma. According to his case report, magnetic resonance image and histopathological examination confirmed the diagnosis of muscular tuberculosis. The following are the reasons for the rare involvement of skeletal muscle in tuberculosis, (1) Muscle contain a high level of lactic acid which inhibit mycobacterium growth, (2) High blood flow of muscle, (3) Absence of reticuloendothelial cells which never allow bacilli to inoculate, and proliferate, (4) Skeletal muscle are well differentiated.

In muscular tuberculosis, inflammatory markers such as lymphocytes, erythrocyte and sedimentation rate is not always elevated. Imaging studies such as ultrasound, computed tomography, and magnetic resonance imaging are used to locate the muscle lesions. Fine-needle aspiration cytology or postoperative biopsy with granuloma is the confirmatory investigations for muscular tuberculosis [Table 1].^[5–7] The treatment of muscular tuberculosis includes local surgical resection along with anti-tuberculous treatment. However in a minority of cases, do not need surgical resection, they do respond well with anti-tuberculous treatment.^[8]

Table 1: Difference between primary and secondary muscular tuberculosis

CONCLUSION

Isolated intramuscular tuberculosis is a rare type of tuberculosis. Muscular tuberculosis must be considered one of the differential diagnoses for the patient with multiple gluteal discharging sinuses. The best investigation to confirm muscular tuberculosis is histopathological confirmation of granuloma. Surgical resection with anti-tuberculous treatment is the standard of care for muscular tuberculosis.

Declaration of patient consent

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Financial support and sponsorship

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Conflicts of interest

There are no conflicts of interest.