A Case of Recurrent Pulmonary Inflammatory Myofibroblastic Tumor with Aggressive Metastasis after Complete Resection
A 47-year-old male patient was referred to our hospital. The patient had discovered a shadow in the upper lung field from a chest X-ray during a medical check-up at an outside hospital on April 2009. A 30-mm sized well-defined low attenuation lesion was observed in the left upper lung on a chest radiography and a computed tomography (CT) (). Positron emission tomography/computed tomography (PET/CT) showed maximum standardized uptake values (SUV) of 10 in the masses in the left upper lung. Bronchoscopy revealed a whitish tumor obstructing the anterior segmental bronchus of left upper lung upper division covered with necrotic material, and biopsy specimens of the tumor was taken during the bronchoscopic examination, and was reported to be spindle cell proliferation according to pathological findings. A radical left upper lobectomy was performed on July 2009 for the purpose of diagnosis and treatment, and an IMT was confirmed by histopathology. On gross examination, the tumor was a single mass with a regular border and adjacent to the bronchus, localized in the lung parenchyma and measured 4.3×3.5 cm (). Microscopic examination revealed spindle cells proliferation without atypia and inflammatory cells (). According to immunohistochemical examination, the myofibroblasts were negative for all cytokeratin, smooth muscle actin, desmin, and Bcl-2. In addition, the myofibroblasts were focally positive for anaplastic lymphoma kinase-1 (ALK1) (). Fluorescence in situ hybridization of ALK rearrangements was not done because of the patient's disagreement. There was no evidence of metastasis with examination of 32 lymph nodes. On postoperative outpatient follow-up, the patient complained of back pain on August 2011, approximately 2 years afterwards. While there was no evidence of recurrence in the lungs from the chest CT performed then, the PET/CT showed multiple bone metastasis (right third rib [SUV, 7.8], thoracic 12th spine [SUV, 10.2], and left sacroiliac bone [SUV, 12.9]) (). According to the biopsy performed on the thoracic spine, a recurrence of the IMT was confirmed. The patient received a total of 36 Gy focal irradiation on the thoracic spine to control the back pain, and was discharged after the pain was alleviated. Afterwards, the back pain aggravated in just 6 months and therefore, the patient made a visit.\nThe patient had no specific past medical history and family history. He has a history of a pack of cigarette smoking for 15 years and quit smoking in 2005. There was no other remark-ability.\nAccording to chest and abdominal check-up, no abnormality was observed, and the patient complained of pain in the left pelvis and pain in the left calf. There were no other specific findings, and there was no clearly palpable tumor.\nAccording to the blood test, the white blood cell count increased to 17,400/mm3, the hemoglobin count was 13.6 g/dL, and platelet was 274,000/mm3, which is within normal range. The blood urea nitrogen, creatinine, liver function test, and electrolyte result were within normal range, and there was a slight increase in C-reactive protein with 1.36 mg/dL. Alkaline phosphatase increased to 130 U/L.\nMultiple pulmonary nodules were observed on the chest CT. PET/CT taken due to the re-aggravated back pain and an aggravation of existing bone metastasis and new bone lesions were observed in the skull base, spine, sternum, both scapulas, pelvis, and both femurs ().\nAfter the patient was hospitalized, an intravenous injection of high dose corticosteroid (methylprednisolone, 2 mg/kg/day) was tried and stereotactic radiation therapy with CyberKnife was administered to 5th lumbar spine metastasis. In addition, prophylactic radiotherapy was administered for weight bearing sight (both hip area) and skull base metastasis.\nOne month after high dose corticosteroid therapy, the patient continued to complain of back pain. Bone scan and CT scan revealed aggravation of pulmonary and bone metastasis. We concluded that corticosteroid was not effective and discontinued administration. For pain control, an additional stereotactic radiation therapy to second lumbar spine and sacrum was performed, and transforaminal 5th lumbar spine root block was undertaken. Afterwards, the patient newly complained of left arm tingling sensation, and T1 and T2 level cord compression was observed, and therefore, additional radiotherapy was administered for the cervical and thoracic spine. During this process, because radiation induced thrombocytopenia was observed, intermittent platelet transfusion was performed.\nOn June 2012, under circumstances where specific treatment plan could not be considered, celecoxib (1,000 mg/day), a selective cyclooxygenase-2 (COX-2) inihibitor, began to be tried. However, the patient newly began to complain of numbness in both legs, and deterioration of their motor grade, and voiding difficulty due to neurogenic bladder. Cervical and thoracic spine CT revealed severe cord compression at T8 and T11 level due to bone metastasis. Although surgery was considered, it was difficult to perform due to thrombocytopenia, and hence, stereotactic radiation therapy was administered. Nonetheless, the patient soon progressed to a state of paraplegia, and urinary catheter was inserted. CT scan showed pleural effusion, and liver, adrenal, and spleen metastasis. Approximately after 3 months of hospitalization, the patient was deceased on July 2012 due to disease progression despite conservative treatment.