Introduction

Tuberculosis (TB) continues to constitute major public health problem worldwide. Despite the introduction of effective antituberculosis therapy, 9.40 million new cases of TB occur annually, and the incidence was still as high as 140 per 100,000 population in 2008.

Tuberculosis can involve any organ in the body. The lung is the most commonly involved site; however, since the pandemic spread of human immunodeficiency virus, extrapulmonary tuberculosis (EPTB) has received more attention. Approximately 85% of reported TB cases are limited to the lung; the remaining 15% involved only extrapulmonary or both extrapulmonary and pulmonary sites [1]. Among EPTB, tuberculous otitis media (TOM) is a very rare disease, accounting for between 0.04% and 0.9% of chronic suppurative otitis media cases [2]. Most cases of TOM are secondary, transmitted from a primary focus. Therefore, to administer correct treatment, it is important to locate the primary TB-affected organ.

In this report, we present the case of a 65-year-old Korean woman who was diagnosed with TOM and endobronchial tuberculosis (EBTB). To the best of our knowledge, this is the first report of a case in which TOM and EBTB coexisted. We describe this unusual case and review the literature.

Case report

A 63-year-old woman was admitted to the Department of Otolaryngology with a 3-month history of mucopurulent otorrhea, hearing impairment, and otalgia in the left ear. She had no family or past histories related to TB infection risk factors. She was taking medication for hypertension and had never smoked. She had no history of diabetes mellitus, malignancy, chronic bacterial otitis media, or corticosteroid therapy. On admission, her laboratory findings were normal, with the exception of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): her ESR was found to be 111 mm/h (normal, <20 mm/h), and her CRP was 113.5 mg/l (normal, <5 mg/l). The human immunodeficiency virus (HIV) test also was negative. A chest radiograph showed airspace consolidation in the right lower and middle lobes. A temporal bone CT scan revealed fluid density in the left mastoid air cells (Fig. 1a). Otoscopic findings showed a large central perforation of the tympanic membrane and swollen middle ear mucosa with granulation tissues (Fig. 1b). Pure-tone audiogram showed conduction deafness, 35 dB of air–bone gap and 50 dB of pure-tone average, in the left ear. The results of the initial stains and cultures of the ear discharge were all negative. She received empirical therapy with cefoperazone/sulbactam for 1 week. However, her symptoms persisted, and a physical examination of the middle ear revealed little improvement.

Fig. 1
figure 1

a Temporal bone computed tomography (CT) scan reveals inflammatory fluid density in the left mastoid air cells and epitympanum. b Otoscopic findings reveal that the tympanic membrane is wet and perforated. The mucosa of the middle ear is swollen and has an altered granulomatous appearance

She consulted our department for evaluation of an abnormal chest radiograph finding. We requested acid-fast bacilli (AFB) staining and culture of a sputum specimen and performed chest computed tomography (CT) scanning and fiberoptic bronchoscopy. The chest CT scan showed multifocal infiltrates with peribronchial distribution and airspace consolidation in the right lower lobe (Fig. 2a). Bronchoscopy revealed focal caseous exudates with mucosal erythema and swelling of the medial segment of the right lower lobe (Fig. 2b). Both endobronchial and tympanic membranous biopsy specimens revealed chronic granulomatous inflammation (Fig. 3). PPD skin test was positive. Additionally, AFB staining and TB polymerase chain reaction (PCR) of bronchial washings and ear discharge were both positive. Furthermore, 4 weeks later, Mycobacterium tuberculosis complex was isolated in culture. We confirmed EBTB and TOM. The patient was treated using a four-drug therapy—isoniazid, rifampin, ethambutol, and pyrazinamide—for 6 months, and her symptoms resolved completely.

Fig. 2
figure 2

a Chest CT scan reveals multifocal infiltrates with peribronchial distribution and airspace consolidation in the right lower lobe. b Bronchoscopic finding demonstrates focal caseous exudates with mucosal erythema and swelling of the medial segment of the right lower lobe

Fig. 3
figure 3

a Biopsy of the bronchus: eosinophilic granuloma with surrounding chronic inflammation is detected in the bronchus specimen. b Biopsy of the middle ear: photomicrograph shows a granuloma with chronic inflammation. Hematoxylin and eosin. a ×400; b ×200

Discussion

Tuberculosis usually affects the lungs, although in up to one-third of cases other organs are involved. In order of frequency, the extrapulmonary sites most commonly involved in tuberculosis are the lymph nodes, pleura, genitourinary tract, bones and joints, meninges, peritoneum, and pericardium. However, virtually all organ systems can be affected [3].

Tuberculous otitis media is a rare disease, usually secondary to transmission from adjacent organs. Early diagnosis of TOM is difficult for various reasons [4]. First, the incidence of TOM induces a low index of suspicion. Second, because its clinical signs are polymorphic and mimic other conditions, many clinicians often overlook it as a possibility. Third, false-negative cultures often occur because of the nature of the Mycobacterium tuberculosis bacillus and also because other bacteria in the specimen can interfere with the growth of the bacillus.

The pathogenesis of TOM is postulated to occur by two mechanisms [5, 6]. One involves the middle ear as the primary focus, in which the organism spreads directly through the eustachian tube, external auditory canal, or perforated tympanic membrane. In the second mechanism, the middle ear is the secondary lesion, to which the organism spreads from a primary focus by the hematogenous or lymphatic systems, or through the eustachian tube. In our patient, the second mechanism was implicated. Organisms in the endobronchus may spread through the eustachian tube during coughing, leading to otitis media.

The primary focus in patients with TOM is mainly the lung. One series reported that pulmonary tuberculosis was diagnosed in 12 of 22 patients with TOM [7]. Skolnik et al. [8] reported that abnormal chest films were seen in 58% of the cases reviewed. Bone and the central nervous system are concomitant lesions according to the literature [9]. However, to date, there have been no reports of the endobronchus being the primary organ affected by tuberculosis, as in our patient. Approximately 10–20% patients with EBTB may have normal chest radiographs [10]. Bronchoscopy and CT are considered to be the techniques of choice for the diagnosis of bronchial involvement. Bronchoscopic biopsy is the most reliable method for diagnosing EBTB; not only histopathological findings but also bronchoscopic findings can be sufficient to establish the diagnosis of EBTB [11].

Tuberculous otitis media is difficult to diagnose in the early stage, and the clinician should rely on clinical suspicion with those patients who have not responded to usual therapeutic measures. Because of the low positivity of AFB culture and the interference of growth by other organisms, tuberculosis-positive rates in ear discharge cultures are between 5% and 30%. Moreover, only 20% are shown positive in tissue staining [4]. Polymerase chain reaction (PCR) is a useful method for rapid diagnosis and is highly sensitive and specific for tuberculosis [12]. Biopsy from granulation tissue is the most reliable diagnostic method for TOM. It is recommended that a patient with TOM be treated using the same anti-tuberculous chemotherapy as other extrapulmonary tuberculosis patients and for at least 6 months [13]. Effective anti-tuberculous drugs have dramatically improved the prognosis. With this treatment, improvement in our patient was noted within a few weeks.

The ear is a very rare site of tuberculosis. Although TOM is not a common cause of chronic otitis media, when a patient does not respond to empirical antibiotic therapy, clinicians should consider this disease to avoid severe sequelae.