Pulmonary lymphomatoid granulomatosis in a 4-year-old girl: A case report

BACKGROUND

Pulmonary lymphomatoid granulomatosis (PLG) is a lymphoproliferative disease associated with Epstein-Barr viral infection occurring mainly in adults and rarely in children. It is characterized by multiple pulmonary nodules. Its diagnosis depends on lung biopsy findings. Most patients are immunodeficient, and it commonly presents in children undergoing chemotherapy for leukemia. We report the case of a child with PLG caused by a mutation in the macrophage-expressed gene 1 (MPEG1), suggesting possible PLG occurrence in children undergoing treatment for pulmonary nodular lesions.

CASE SUMMARY

This study reports a case of PLG without apparent immunodeficiency, suggesting the possibility of this disease occurrence during the treatment of pulmonary nodular lesions in children. Initially, the cause was assumed to be an atypical pathogen. Following conventional anti-infective treatment, chest computed tomography findings revealed that there were still multiple nodules in the lungs. Additionally, the patient was found to be infected with the Epstein-Barr virus. Histopathological examination of the resected lung revealed lymphoproliferative lesions with necrosis. Small lymphocytes, plasma cells, and histiocytes were observed in the background, although Reed-Sternberg cells were absent. Immunohistochemical staining [CD20(+), CD30(+), and CD3(+)] and EBV-encoded small RNA1/2 in situ hybridization of small lymphocytes revealed approximately 200 cells/high-power field. Whole exon sequencing of the patient revealed a mutation in the MPEG1. The patient was eventually diagnosed with PLG and transferred to the Department of Pediatric Oncology for bone marrow transplantation.

CONCLUSION

As PLG is rare and fatal, it should be suspected in clinical settings when treatment of initial diagnosis is ineffective.

An atypical case of a pulmonary mass in an immunocompromised patient

OBJECTIVES

Pulmonary lymphomatoid granulomatosis (PLG) is a rare angiocentric and angiodestructive EBV-associated lymphoproliferative disorder which almost always affects the lungs. PLG is more commonly diagnosed in patients with immunodeficiency and is associated with Epstein-Barr virus (EBV). 'Drug induced PLG' or 'iatrogenic immunodeficiency-associated lymphoproliferative disorder' is a special form of PLG described in patient with inflammatory bowel diseases treated with Azathioprine.

METHODS

We report a case of drug-induced PLG in a 68-year-old patient with Crohn's disease presenting with pain at the right hemithorax, fatigue and shortness of breath with a pulmonary mass.

RESULTS

Although initial diagnostic findings were misleading, an open lung biopsy eventually led to the diagnosis of drug-induced PLG.

CONCLUSION

The diagnosis of PLG is challenging because the disease is rare and the histological features can be very subtle. Correct diagnosis relies on histopathology and immunohistochemical staining and EBV RNA in situ hybridization with sampling of large and different amounts of pathologic tissue in the hands of expert pathologists. In drug-induced PLG specifically, withdrawal of the immunosuppressive agent can lead to disease regression.

Pyrexia, Lung nodules, Granulomas: Pulmonary Lymphomatoid Granulomatosis

The differential diagnosis of pyrexia, lung nodules and granulomas includes tuberculosis, vasculitis and rarely a malignancy. In countries where tuberculosis or histoplasmosis is endemic, these are the first consideration and often ruled out by microbiological investigations. Vasculitis like granulomatosis with polyangitis (Wegener's granulomatosis), Churg strauss syndrome and sarcoidosis, which are the second consideration, are ruled out by serological investigations. Confirmation of malignancy merits histopathology. This case highlights how a rare diagnosis of pulmonary lymphomatoid granulomatosis was reached after an open lung biopsy. The following case also describes the natural history of this rare disease as it showed transient spontaneous remission but ultimately required therapy.