|Year : 2021 | Volume
| Issue : 2 | Page : 153-155
An adolescent with mediastinal lymphadenopathy: What lies within?
Sachin Singh1, Joseph L Mathew1, Sahajal Dhooria2, Kushaljit Singh Sodhi3, Parikshaa Gupta4, Pankaj Vaidya1, Meenu Singh1
1 Department of Pediatrics, PGIMER, Chandigarh, India
2 Department of Pulmonary Medicine, PGIMER, Chandigarh, India
3 Department of Radiodiagnosis and Imaging, PGIMER, Chandigarh, India
4 Department of Cytology and Gynecological Pathology, PGIMER, Chandigarh, India
|Date of Submission||26-Feb-2021|
|Date of Decision||15-Mar-2021|
|Date of Acceptance||14-May-2021|
|Date of Web Publication||31-May-2021|
Prof. Joseph L Mathew
Advanced Pediatrics Centre, PGIMER, Chandigarh
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Singh S, Mathew JL, Dhooria S, Sodhi KS, Gupta P, Vaidya P, Singh M. An adolescent with mediastinal lymphadenopathy: What lies within?. Indian Pediatr Case Rep 2021;1:153-5
|How to cite this URL:|
Singh S, Mathew JL, Dhooria S, Sodhi KS, Gupta P, Vaidya P, Singh M. An adolescent with mediastinal lymphadenopathy: What lies within?. Indian Pediatr Case Rep [serial online] 2021 [cited 2021 Jun 19];1:153-5. Available from: http://www.ipcares.org/text.asp?2021/1/2/153/317361
We report a child who was referred to us with a history of fever and cough for 1 month but whose physical examination yielded no abnormalities. However, mediastinal widening was evident on the chest X-ray. Therefore, the major clinical differential diagnoses considered were thoracic tuberculosis (TB), Hodgkin lymphoma, or sarcoidosis. The learning objectives of this case are to highlight a stepwise approach to establish etiological diagnosis in a case of mediastinal lymphadenopathy, so that specific (rather than empiric) therapy can be instituted. Investigations that can confirm the diagnosis should be preferred over those that may be less helpful, even if they are easier to perform. This case also highlights the necessity of diligent efforts to confirm TB before starting treatment.
| Clinical Description|| |
An 11-year-old boy presented to a private practitioner in the month of January, with fever and cough lasting a month. The fever occurred daily, was of moderate intensity, peaking to 102°F, and without any diurnal variation. It was associated with a dry, intermittent cough, without diurnal variation, postural variation, or sleep disturbance. There was no history of breathing difficulty, chest in drawing, or limitation of activity. There were no specific aggravating or relieving factors or history suggesting postnasal drip. There was no history of decreased appetite, weight loss, night sweats, joint pains, rash, or redness of the eyes. There was no history of contact with TB. The child was immunized as per the National Immunization Schedule. He had received treatment with oral antibiotics, oral bronchodilators, and two different cough syrup mixtures but did not improve. Therefore, he was referred to our institution for further evaluation.
On examination, the heart rate was 90/min, respiratory rate 20/min, temperature 101°F, SpO2 98% in room air, and blood pressure 117/75 mmHg. The body mass index was 23.9 corresponding to +1.62 Z-score. General physical examination did not reveal pallor, cyanosis, icterus, edema, or significant lymphadenopathy. Throat and sinus examinations were normal. Respiratory system examination showed symmetric chest expansion, centrally positioned trachea, no mediastinal shift, normal percussion note in all areas, and bilaterally equal vesicular breath sounds without crackles or wheeze. Examination of the other systems was unremarkable.
A screening chest X-ray was done in view of the persistent cough [Figure 1].
What are the salient findings in the chest X-ray?
The striking finding was the mediastinal widening, which suggested significant right paratracheal lymphadenopathy. There was no significant pulmonary parenchymal involvement or pleural effusion. The trachea, bones, and soft tissues appeared normal. It was difficult to comment on subcarinal nodes from this X-ray film.
What are the clinical possibilities based on the clinical history and radiograph?
We considered thoracic (mediastinal) TB and also sarcoidosis as well as lymphoreticular malignancy (especially Hodgkin lymphoma). These differential diagnoses were considered because the clinical symptoms of 1-month duration, normal physical examination including respiratory examination, and mediastinal widening on the chest X-ray could occur in any of these conditions.
What should be the line of investigations?
We investigated the child as per the differential diagnoses considered. First, we investigated for TB. Since there was no sputum even after induction, we collected gastric lavage after overnight fasting. This was processed by Ziehl–Neelsen (ZN) staining for acid-fast bacilli (AFB), cartridge-based nucleic acid amplification test (GeneXpert), and liquid medium mycobacterial culture. ZN staining and GeneXpert were negative. In addition, a tuberculin skin test was done, which was reactive (26 mm × 18 mm).
Investigations performed for Hodgkin lymphoma showed normal blood counts, differential count, peripheral smear, and erythrocyte sedimentation rate. Noninvasive biomarkers for lymphoma and germ-cell tumors were assessed. Lactate dehydrogenase was 417 U/L (normal range: 60–170 U/L), alpha-fetoprotein was 0.988 IU/mL (normal range: 0–5.8 IU/mL), and human chorionic gonadotropin was 0.5 mIU/mL (normal <1 mIU/mL).
We also explored the possibility of sarcoidosis by analyzing serum calcium, creatinine, alkaline phosphatase, alanine and aspartate aminotransferases, serum level of angiotensin-converting enzyme, 24-h urine calcium–creatinine ratio, and eye fundus examination. These were all normal.
What other investigations can be planned?
At this stage, we proceeded with fiber-optic bronchoscopy and bronchoalveolar lavage (BAL) to examine the airway for extrinsic compression and analyze BAL fluid for evidence of TB, malignant cells, and sarcoidosis. Airway anatomy was normal. BAL fluid was negative for TB on ZN staining and GeneXpert. A sample was processed for liquid medium culture. The BAL lymphocyte count and CD4:CD8 ratio were normal which made sarcoidosis unlikely, a ratio of >2 being suggestive, and a ratio of >4 being consistent with sarcoidosis.
Recognizing the need for a tissue diagnosis, we then performed a computed tomography (CT) scan of the thorax to localize a site for mediastinal lymph node aspiration. It is pertinent to note that CT scans are associated with significant radiation dosage and do not offer a confirmatory diagnosis in most cases. Hence, it was performed after bronchoscopy and BAL in this case. The representative sections of the CT scan are shown in [Figure 2].
What are the salient findings in the computed tomography scan images?
The CT scan showed a hypodense mass lesion (measuring 4.2 cm × 3.2 cm) in the right paratracheal location, extending beyond the paratracheal region, to the precarinal and subcarinal locations as well. These appeared to be multiple lymph nodes of variable sizes, the largest measuring 14 mm. The lung parenchyma was normal.
The next option for a tissue diagnosis was either a CT scan-guided mediastinal lymph node aspiration or endoscopic bronchial ultrasound (EBUS)-guided lymph node aspiration. We proceeded with the latter because the age of the child, size and position of the lymph nodes, and experience of the operator made it feasible in this case. It also avoided the need for additional radiation. Examination of the lymph node aspirate showed a reactive population of lymphoid cells with occasional histiocytic collection and few necrotic fragments without granulomas. ZN stain was positive, confirming the presence of AFB. However, GeneXpert of the sample was negative. There were no abnormal cells suggesting lymphoma. This suggested the diagnosis as mediastinal TB, although culture was awaited for confirmation.
| Management and Outcome|| |
Standard antituberculosis treatment (ATT) was started using four drugs (isoniazid, rifampicin, pyrazinamide, and ethambutol), administered daily along with pyridoxine. The child was discharged. On follow-up after 1.5 months, he was afebrile, had no cough or breathing difficulty, had increased appetite, and had gained 2-kg weight. Mycobacterial culture reports of gastric lavage samples, BAL, and mediastinal lymph node aspirate were all negative. The child was administered first-line ATT for 6 months and remained well. As mediastinal lymph node resolution may take longer, a follow-up chest X-ray is planned 6 months after cessation of therapy.
| Discussion|| |
TB is one of the most common infectious diseases worldwide. Due to the paucibacillary nature of the illness in children, confirming the diagnosis is a great challenge. Mediastinal lymph node involvement is one of the forms of extrapulmonary TB.
Mediastinal lymph node TB without parenchymal lesions poses an even greater diagnostic challenge due to the relative inaccessibility of tissue specimens.
In the majority of children with mediastinal lymphadenopathy, involvement occurs in more than one location. In a study conducted on 100 children, the mediastinal lymph node involvement was mostly in the subcarinal (90 patients), hilar (85 left, 72 right, and 61 bilateral), axillary (79 cases), precarinal (64 cases), and right paratracheal (63 cases) locations. Plain radiography is not reliable to confirm the etiology of mediastinal lymphadenopathy. CT scans have an advantage over plain X-ray chest, as lymph node necrosis is suggestive of TB, whereas sarcoidosis and lymphoma lack necrosis. The absence of lymph node necrosis in the index child necessitated invasive tissue diagnosis. In cases with lymphoma, there is a homogeneous enhancement of lymph node. For confirmation of the diagnosis, lymph node sample using EBUS-guided transbronchial needle aspiration is required for histopathology; CT scans help in the localization of the site for aspiration or biopsy.
AFB can be positive in nontubercular mycobacterial (NTM) infections and also nocardiosis and actinomycosis. However, establishment of NTM pulmonary disease requires clinical, radiographic, and microbiologic confirmation by culture. Clinically, these usually occur in immune-compromised patients. Typical radiological features are fibrocavitary lesions or regions of bronchiectasis, nodular infiltrates, consolidation, and tree-in-bud opacities on CT scan.
The prognosis of mediastinal lymphadenopathy depends on the underlying etiology, location, and associated parenchymal lesions. The assessment of response to antituberculosis therapy does not require a chest X-ray on completion of the intensive phase, if there is clinical improvement. It may only be indicated when there is persistence of symptoms or the desired response seems to be slow. An X-ray may be done on completion of the continuation phase to document response, although lymph node resolution may take longer. If there is airway compression by enlarged lymph nodes, corticosteroids are prescribed for 4 weeks followed by tapering over the next couple of weeks before omission.
| Conclusion|| |
This child with fever, cough, normal physical examination, and mediastinal widening on chest X-ray underwent a stepwise approach to confirm the diagnosis. Ultimately, invasive tissue diagnosis by endoscopic bronchial ultrasound (EBUS)-guided mediastinal lymph node aspiration confirmed TB. This case highlights several learning points for clinicians.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2]