Abstract
Keywords
Case report
A 5-year-old child was presented to a general practitioner with cough and wheezing for a fortnight’s duration. He neither had a past history of wheezing nor a family history of bronchial asthma. There was no history of contact with tuberculosis. The only clinical findings were bilateral basal lung wheezing and crepitation. He did not improve with bronchodilator and antibiotic treatment. A chest radiograph revealed miliary mottling (Figure 1a). Blood parameters were normal, and the Mantoux test, gastric juice for acid fast bacilli and TB quantiferon test were negative. However since miliary mottling was seen, the child was treated empirically with anti-tuberculosis treatment but showed no improvement neither clinically nor radiologically.
Radiological findings of LCH.
Further physical examination on review after 6 weeks revealed a 3 × 2 cm scalp swelling in the left parietal region. A skeletal survey then revealed two well-defined lytic lesions in the skull. (Figure 1b).The thoracic computed tomography (CT) showed randomly distributed nodular shadows in both lung fields (Figure 1c). Histopathological examination of the scalp swelling was suggestive of Langerhans's cell histiocytosis (LCH). The only lesions found were those in the skull and the lungs. A lung biopsy was refused by his parents. The child was categorised as Group III LCH with high-risk organ involvement (Group III is single system and any risk organ involved; spleen, liver, hematopoietic system and lungs are classified as risk organs). He was started on Inj. Vinblastine and oral Prednisolone, and after 12 cycles the child showed healing radiologically. Currently, the child is on continuation phase with third weekly chemotherapy with Inj. Vinblastine, oral Prednisolone and daily 6 Mercaptopurine for 1 year. Since it is not an isolated pulmonary involvement and after 12 weeks of chemotherapy there is a reduction in the pulmonary lesion as seen in X-ray and CT films, a diagnosis of LCH with pulmonary involvement was made.
Discussion
In the paediatric age group, the causes of miliary mottling include miliary tuberculosis, tropical pulmonary eosinophilia, fungal infections, varicella pneumonia, hemosiderosis, sarcoidosis, toxoplasmosis, syphilis, metastatic lesions and histiocytosis.
One must also keep in mind that tuberculosis can coexist in patients with LCH as immunosuppression will inevitably be present. 1
This was demonstrated convincingly in a postmortem case in 1994. 1
Pulmonary LCH (PLCH) occurs both as an isolated finding and more frequently, as part of multi-system involvement. While isolated PLCH is seen more commonly in adults, it is infrequent in children. There is a strong association with cigarette smoking, which is reported in over 90% of the patients.2–4 Apart from an exceptional case reported by Farhan et al., who described a left intraluminal lesion in the left main bronchus in a 2-year-old girl, lung involvement is conventionally parenchymal. 5 PLCH with pneumothorax has also been reported. CT scan is needed to differentiate between nodules and cysts as well as in estimating the degree of the disease. These radiological changes are not specific, and biopsy is needed to establish the diagnosis. PLCH is associated with a favourable prognosis when there is no risk of organ involvement. 6 The occurrence of malignancy and its association with paediatric PLCH is well known. 7 The high-resolution CT (HRCT) pattern of nodular and cystic changes that involves the upper and middle lobes with the involvement of lung bases is highly suggestive of PLCH in children. Factors associated with poor outcome include extremes of age, multiorgan involvement, prolonged constitutional disturbances, severely reduced diffusion capacity, extensive cysts and recurrent pneumothoraces, honeycombing on imaging, associated pulmonary hypertension and prolonged treatment. 8
Conclusion
In children with miliary shadowing in the lungs, a thorough history and physical examination should be done before initiating anti tubercular treatment, as a specific physical sign, as identified in our case could provide a clue to an alternate diagnosis. Non-response to TB treatment should drive the search for an alternative diagnosis.9,10
Footnotes
Declaration of conflicting interests
All the authors have seen the manuscript and approve it for submission. The authors have no competing interest in the publication of the manuscript to declare.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.