Langerhans Cell Histiocytosis Followed by Hodgkin's Lymphoma
A 22-year-old man with lower back pain of one month in duration was referred to our institution. The results of laboratory investigations and neurological examinations were normal. A bone scan, computed tomography (CT) scan and magnetic resonance imaging (MRI) suggested tuberculous spondylitis on the thoracic and lumbar spine. The patient underwent anterior thoracic corpectomy to obtain specimens for pathologic examination. No acid-fast bacilli were identified by Ziehl-Neelsen staining. An excisional biopsy of the osteolytic T2 spinal lesion showed extensive intramedullary proliferation of histiocytic cells with folded nuclei, numerous eosinophils, phagocytic histiocytes, and fibroblasts (). The bone spicules were thinned with numerous osteoblasts and osteoclasts. Immunostaining assays for CD1a and S100 were strongly positive in histiocytes with folded nuclei, suggesting LCH. Whole body positron emission tomography (PET; 18F-fluorodeoxyglucose, 18F-FDG) revealed other lesions in the sternum and left sacral ala. The multiple lesions of the spine, sternum, and sacrum were treated with involved-field radiotherapy. Subsequent FDG-PET scans revealed that the original lesions had completely disappeared, but that new hypermetabolic lesions had appeared in the subcarinal lymph node, left hilar lymph node, and left ischium. We determined that LCH had become systemic and the patient was treated with a combination of various chemotherapeutic agents in six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP). Complete remission was achieved.\nOne year after the patient entered remission, he developed right cervical lymphadenopathy. No other symptoms were reported. An excisional biopsy of the right cervical lymph node was performed. The extracted lymph node was smooth and measured 4.6 × 3.7 × 1.5 cm (). The cut surface was a glistening tan yellow color and displayed diffuse nodularity.\nMicroscopic examination at a magnification of × 100 showed a broad sclerotic fibrous band dividing the lymph node into multiple nodules containing large, scattered, and atypical cells (). Further examination at a higher magnification showed that the atypical cells were either mononucleated or binucleated, with prominent nucleoli and abundant cytoplasm (). Residual LCH was observed within fibrous bands around the nodules. Immunostaining revealed CD1a-positive Langerhans cells in the residual histiocytes within the sclerotic bands, and large, atypical, CD30 (Ki-1)-positive cells (× 400). We diagnosed the patient with HL secondary to LCH (). FDG-PET imaging and CT scans of the patient's thorax, abdomen, and pelvis revealed involvement of the right lung, right level II cervical lymph nodes, T12, L5, right 3rd rib anterior arc, right ischium, and right ilium. The patient received three cycles of ESHAP (methylprednisolone, etoposide, cisplatin, and cytosine arabinoside) chemotherapy, followed by high-dose chemotherapy (busulfan, etoposide, and cyclophosphamide) and autologous stem cell transplantation (ASCT). Ten months after ASCT, the patient reported no further symptoms of the disease, and FDG-PET scans were negative for hypermetabolic lesions.