Conclusion In case there is multiple myeloma, physicians must be aware that severe respiratory distress symptoms not giving an answer to treatment of common causes is actually a manifestation of the condition, with negative BAL or biopsy also. common interstitial illnesses in case there is severe respiratory failing. 2. Case Record A 61-year-old guy was identified as having an immunoglobulin G (IgG) kappa multiple myeloma, Salmon and Durie stage III B, and t(4; 14) translocation. His past health background included active chronic and smoking respiratory failing with emphysema. He was treated by bortezomib-thalidomide-dexamethasone (BTD) and then autologous stem cell transplantation conditioned by melphalan 200?mg/m2 4 months later. Ponesimod He had a partial response and then received 2 cycles of BTD as consolidation therapy. He presented progressive disease 6 months later with anemia, thrombocytopenia, and increase of serum M-protein (IgG em /em ) of 28?g/L (normal 12?g/L). He was then admitted for recurrent fever, cough, and dyspnea. Laboratory data revealed a positive influenza B sample. Routine blood investigation showed the following results: hemoglobin (8.9?g/dL), total leukocyte count of 6.510/mm3 with neutrophils (68%), lymphocytes (8%), monocytes (8%), metamyelocytes (3%), myelocytes (6%) and plasma cells (7%), and platelet count of 12,000/mm3. The chest radiograph showed bilateral multifocal areas of nodular infiltration. High-resolution computed tomography of the thorax FAAP95 showed severe bullous emphysema and diffuse, patchy, multifocal air space infiltration bilaterally with nodular character, small bilateral pleural effusions, mediastinal lymphadenopathy, and a known lytic lesion of the 12th vertebra. Computed tomography of the brain did not reveal argument for brain injury or involvement. He was first treated by piperacillin-tazobactam, amikacin, oseltamivir, and methylprednisolone 1?mg/kg/day for 12 days. The patient’s respiratory status quickly declined and he was admitted to the ICU requiring intubation and mechanical ventilation. Bronchoalveolar lavage (BAL) yielded fluid did not reveal malignant cells or pathogens. He presented a delirium and agitation syndrome. The cerebrospinal fluid (CSF) examination showed Ponesimod an IgG count of 354?mg/mL (normal 35?mg/mL), proteinorachia of 1 Ponesimod 1.23?g/L, glycorrhachia of 3.9?mmol/L, 700 red blood cells, and 2 normal white blood cells per microliter without plasma cells. Ponesimod He received other antimicrobial therapies for pneumonia and methylprednisolone for myeloma. He was Ponesimod judged to be a poor candidate for more aggressive salvage therapy taking into account the poor prognosis associated with t(4; 14) translocation and the progressive multiorgan failure. In keeping with the patient’s advance directive and after consultation with his family, supportive care was withdrawn. Autopsy revealed diffuse and nodular infra-centimetric infiltration of the lung parenchyma by neoplastic plasma cells. Immunohistochemistry confirmed the pulmonary infiltration of monotypic plasma cells in the lung biopsy (Figure 1). Open in a separate window Figure 1 (a) Computed tomography thorax revealed severe bullous emphysema and diffuse, patchy, multifocal air space infiltration bilaterally with a nodular character, small bilateral pleural effusions, and mediastinal lymphadenopathy. (b) Lung tissue specimen from the autopsy revealing nodular tumoral infiltrate (hematoxylin and eosin 2.5). (c) Lung tissue specimen from the autopsy revealing characteristic abnormal plasma cell infiltrates (hematoxylin and eosin 40). (d) Immunohistochemical staining of the tissue specimen showing multiple myeloma cell positive for IgG (original 40). 3. Discussion Extramedullary dissemination of multiple myeloma occurs in advanced disease, but it is rare. The sites of extramedullary dissemination are spleen, liver, lymph nodes, kidney, thyroid or adrenal glands, testes, ovary, pericardium, intestinal tract, and skin, while lung.