Intravascular large B-cell lymphoma with hot lung sign diagnosed by transbronchial lung cryobiopsy

Le résumé fourni par la source

An 83-year-old man was hospitalized for persistent fever and dyspnea. Chest computed tomography (CT) showed diffuse ground-glass shadows in the bilateral lungs. Laboratory tests ruled out collagen disease and infectious disease, and intravascular lymphoma (IVL) was suspected based on decreased blood counts [hemoglobin (Hb) 8.4 g/dl and platelet (Plt) 54 000/µl] and elevated soluble interleukin-2 receptors (5770 U/ml, normal 157–474 U/ml) and lactase dehydrogenase (LDH) (1357 U/l, normal 115–245 U/l). The patient had no significant lymphadenopathy. A random skin biopsy was performed; however, no diagnosis was obtained. Based on the ‘hot lung’ sign on positron emission tomography (PET)-CT (Figure 1a), we suspected the presence of lung involvement and performed a transbronchial lung cryobiopsy (TBLC) of the right lower lobe. Hemorrhaging was moderate but could be controlled. A diagnosis of intravascular large B-cell lymphoma (IVLBCL) was made based on the presence of CD20-positive, PAX5-positive, large atypical mononuclear cells in the pulmonary capillaries (Figure 1b). The patient was treated with steroids, his fever and dyspnea symptoms were relieved and he was later transferred to a hematologic oncology institution. (a) Fluorodeoxyglucose (FDG)-PET-CT showed FDG accumulation in bilateral lungs, also known as the hot lung sign. (b) H&E staining of the biopsy specimen showed atypical lymphocytes in the capillaries in the alveolar septum. The scale bars represent 50 μm. H&E, hematoxylin and eosin. IVLBCL is a rare disease defined by an accumulation of large neoplastic B cells within the lumina of blood vessels. Primary or predominantly pulmonary IVL has a poor prognosis.1 Random skin biopsy is a relatively non-invasive biopsy method; however, its diagnostic rate is only 22%.2 Although the hot lung sign on fluorodeoxyglucose-PET is a reason to suspect IVL,3 transbronchial lung biopsy is not ideal for diagnosing lung lesions because of the small specimen size, and the diagnostic yield is only 30–50%.4 The usefulness of TBLC of the lungs in lymphoproliferative diseases has recently been reported.5 Some have also reported the value of TBLC for IVL.6 In our case, TBLC allowed us to quickly diagnose IVL and initiate treatment. TBLC is beneficial in the diagnosis of IVL with a positive hot lung sign. Informed consent was obtained from the family of the patient for reporting this case. Conceptualization; T.S. Data curation; H.M. and D.N. Formal analysis; Y.K. and H.W. Investigation; Y.Y. Roles/Writing—original draft; T.S. Writing—review & editing; H.C. All authors have read and approved the final version of the manuscript. The authors thank Editage (www.editage.jp) for English language editing. Conflict of interest: None declared.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.