Disseminated tuberculosis masquerading as depression

Case report

A 23-year-old man was referred by a psychiatrist with symptoms of profound fatigue, depressed mood, diminished interest in his routine activities, increased daytime somnolence, and significant weight loss of two months’ duration. On further evaluation, he also gave a history of intermittent dry cough, continuous low-grade fever associated with an evening rise in temperature and backache for two months.

On clinical examination, his pulse was regular; 110/minute, blood pressure 120/80 mmHg, afebrile (temperature 37°C), and bilateral non-tender cervical lymph nodes were palpable.

He had no adventitious respiratory sounds. Although he had mild thoracic scoliosis, no tender points were noted on the spine. Initial laboratory investigations (Table 1) showed a raised erythrocyte sedimentation rate (130 mm/h), anemia (Hb 95 g/L), and raised uric acid (0.59 mmol/L) with elevated c-reactive protein (63.25 mg/L). Urine and blood cultures were sterile, while serum protein electrophoresis and urine for Bence Jones proteins were negative. Although the Mantoux test was positive, he could not provide adequate sputum for acid-fast bacilli staining.

OPEN IN VIEWER

Table 1.

Blood investigations.

Tests	Values	Reference range
ESR (mm/h)	130	0–20
Haemoglobin (g/L)	95	130–170
Haematocrit (%)	29.5%	40–50%
RBC count (×106/µL)	3.5	4.5–5.5
Uric acid (mmol/L)	0.59	0.26–0.45
C-reactive protein (mg/L)	63.25	0–5
Ferritin (ng/mL)	617.9	20–250
Globulin (g/dL)	4.7	2–3.5
Serum albumin (g/dL)	3.4	3.5–5.0

Chest radiography, ECG, and echocardiography were within normal limits, while an ultrasound scan revealed splenomegaly. A thoraco-abdominal CT scan revealed patchy consolidatory changes in the right upper and middle lobes (Figure 1), enlarged supraclavicular, upper para-tracheal, and para-aortic lymph nodes, and multiple ill-defined lytic lesions in the cervical, thoracic and lumbosacral vertebrae including the sternum (Figures 2 and 3). A bone marrow aspiration and biopsy indicated infection-associated changes, while ultrasound-guided fine-needle aspiration cytology (FNAC) of the supraclavicular lymph node revealed granulomatous lymphadenitis, but failing to produce conclusive evidence for tuberculosis. Hence a CT-guided biopsy was performed on the left pedicle of the T12 vertebra but this showed no evidence of lymphoma nor any evidence of tuberculous granuloma.

OPEN IN VIEWER

Figure 1.

CT thorax with contrast showing patchy consolidatory changes in the right upper and middle lobes.

OPEN IN VIEWER

Figure 2.

CT thorax with contrast showing lytic lesions in the sternum.

OPEN IN VIEWER

Figure 3.

CT abdomen with contrast showing lytic lesions in the vertebra.

Despite confirmatory evidence, disseminated tuberculosis was strongly suspected, with Hodgkin's lymphoma and multiple myeloma being the primary differential diagnoses. Although there was no history of any suicidal ideation, guilt or hopelessness, a single episode of depressive disorder was suspected to be co-existing with systemic illness and could not thus be excluded.

During his hospital stay, our patient had a persisting fever which was managed conservatively. In view of the strong clinical suspicion of tuberculosis and positive Mantoux test, the patient was empirically started on anti-tubercular therapy (ATT). He was discharged and referred to a hospital closer to his hometown at his request. At a follow-up visit after six months, it was discovered that our patient had undergone an open biopsy of his sternal osteolytic lesion, which revealed caseating granuloma, confirming the clinical diagnosis of disseminated tuberculosis. On subsequent follow-up, there was a gradual recovery of his depression within three months of initiating ATT associated with a weight gain of 20 kg after six months. ATT was however continued for one year to ensure a complete cure.

Discussion

Tuberculosis is one of the leading causes of death worldwide, and there were 1.3 million tuberculosis deaths and 10 million incident cases in 2020. ¹ While pulmonary tuberculosis is the most common form, extra-pulmonary tuberculosis poses a diagnostic dilemma as it can affect any system of the body with skeletal tuberculosis accounting 10–20% of extra-pulmonary cases. The most commonly involved sites are the spine, femur, tibia, and fibula, affecting any age group. ²

Tuberculosis often occurs due to endogenous reactivation of latent foci seeded during initial bacteremia. The hematogenous or lymphatic route also acts as a channel for dissemination from a reactivated pulmonary site. ² Skeletal tuberculosis can have a myriad of presentations, often mimicking malignancy and other diseases; hence it is imperative to rule out chronic infections such as brucellosis, actinomycosis, melioidosis, degenerative disc disease, and multiple myeloma.

There is a close association of depression with tuberculosis, often requiring adequate screening and management along with ATT. ³ According to ICD-11 criteria, a person with clinical depression must have at least five out of a list of ten symptoms, occurring most of the day for at least two weeks and resulting in significant impairment in functioning. The ten symptoms are: depressed mood, markedly diminished interest in activities, reduced ability to concentrate, beliefs of low self-worth or inappropriate guilt, hopelessness about the future, recurrent thoughts of death or suicidal ideation, significantly disrupted sleep or excessive sleep, significant changes in appetite or weight, psychomotor agitation or retardation, and reduced energy or fatigue.

The management of skeletal/disseminated tuberculosis is the same as that for pulmonary tuberculosis as there is good bone penetration by anti-tubercular drugs, but the duration of therapy should be longer. ⁴ Multidrug ATT viz. isoniazid, rifampicin, ethambutol, and pyrazinamide are given for a period of 9–12 months, or longer depending upon clinical recovery and remission. It is imperative to initiate empirical ATT if there is strong clinical suspicion of skeletal/disseminated tuberculosis, even in the absence of conclusive evidence to prevent further complications from the disease. ⁵