Juvenile xanthogranuloma is a benign self-limiting lesion commonly described in infants and young children. It most commonly involves the skin presenting as single or multiple yellowish-brown papules. Clinical scenario with the classic histomorphology showing histiocytic aggregates in the dermis with xanthomatous cytoplasm, toutan type giant cells, immunohistochemistry with positive CD68, CD163, factor XIIIa and negative CD1a and S-100 help in diagnosis. However, diagnosis becomes challenging with predominant systemic bone marrow involvement in post-B-lymphoblastic leukemia settings.

Sarcoidosis is a systemic granulomatous disease characterized by the hyperactivation of CD4 T cells, CD8 T cells, and macrophages. Clinical presentations of sarcoidosis are highly variable. Sarcoidosis is unknown in its etiology, but it suggests it may result from exposure to specific environmental agents in genetically susceptible people. Sarcoidosis commonly involves the lungs and lymphoid system. Bone marrow involvement in sarcoidosis is uncommon. Sarcoidosis rarely results in intracerebral hemorrhage due to severe thrombocytopenia secondary to bone marrow involvement. We present the case of a 72-year-old woman who has been in remission from sarcoidosis for 15 years and developed intracerebral hemorrhage secondary to severe thrombocytopenia due to sarcoidosis recurrence in the bone marrow. The patient presented to the emergency department with a generalized, non-blanching petechiae rash and nose and gum bleeding. Her labs showed a platelet count of less than 10.000/mcL, and computed tomography (CT) showed intracerebral hemorrhage. A bone marrow biopsy revealed a small, non-caseating granuloma indicative of a sarcoidosis relapse in the bone marrow.

Mantle cell lymphoma (MCL) is a B-cell non-Hodgkin lymphoma with an advanced stage; it occurs frequently and affects the lymph nodes, spleen, blood and bone marrow. The synchronous occurrence of MCL bone marrow involvement (MCLBMI) and malignant tumors is extremely rare. To the best of our knowledge, synchronous extensive-stage small cell lung cancer (ES-SCLC) and MCLBMI have not been previously reported. In the present study, a rare case of ES-SCLC with synchronous MCLBMI is reported in a 59-year-old man. The patient received cisplatin, etoposide, dexamethasone and rituximab chemotherapy for the treatment of both malignancies. The follow-up computed tomography scan disclosed regression of the left upper lobe mass and the routine blood test indicated that the platelet count was gradually increasing to normal levels. Following therapy, the patient achieved a partial response. The experience in this case report indicated that the treatment of synchronous SCLC and MCLBMI requires consideration of the respective patient clinical features, biological behavior and cumulative toxicity of the treatment regimens administered for both malignant tumors. The present study demonstrated that thrombocytopenia was not a chemotherapy contraindication, thus providing a new treatment option for this type of patient.

Bone marrow involvement (BMI) of solid tumors is a special type of distant metastasis. It has an occult onset, atypical clinical and laboratory features, and a high mortality. We present a nasopharyngeal carcinoma case with cervical and axillary lymph nodes, bilateral lung, multiple bone, and bone marrow metastases, who was treated chemotherapy plus targeted therapy under the guidance of a patient-derived tumor xenograft (PDTX) model, followed by maintenance chemotherapy plus immunotherapy. The patient\'s symptoms were relieved after four cycles of chemotherapy plus targeted therapy. His bone marrow biopsy turned negative after 7 months of therapy. In addition, his total peripheral T cells as well as the proportion of CD8+ T cells increased during the course of therapy. The combination of chemotherapy, targeted therapy, and immunotherapy provides an effective antitumor regimen for advanced NPC patients with BMI.

A 58-year-old male was admitted to our hospital due to lasting fever, progressive lymphadenopathy and bicytopenia, with a previously histological diagnosis of follicular lymphoma grade 3a with Epstein-Barr virus-encoded RNA positive one month ago. A second biopsy of axillary lymph node revealed concurrent diffuse large B-cell lymphoma with Epstein-Barr virus-encoded RNA positive. Another diagnosis of hemophagocytic lymphohistiocytosis secondary to Epstein-Barr virus positive diffuse large B-cell lymphoma was further concluded by clinical manifestation, laboratory test and atypical lymphocytes in peripheral-blood smear. After a pulse of steroid pre-phase treatment, the patient\'s clinical condition deteriorated and died in two weeks. The presence of Epstein-Barr virus infection in patients with follicular lymphoma is associated with more aggressive clinical course and increased risk of high-grade transformation. Hemophagocytic lymphohistiocytosis in response to Epstein-Barr virus infection or lymphoma remains fatal. Early diagnosis and initiation of treatment may improve the outcome.

Renal and bone marrow involvements in sarcoidosis are rare. We experienced the case of a 67-year-old man with systemic sarcoidosis, with bone marrow involvement, hepatic involvement and a unique constellation of renal lesion with cellular crescent formation. Immunosuppressive therapy was helpful for maintaining the stability of his pancytopenia, hepatic function and renal function. To the best of our knowledge, the association between sarcoidosis, bone marrow involvement and crescentic glomerulonephritis has been reported in only few cases in literature.

Initial extranodal osseous presentation of Classic Hodgkin lymphoma (CHL) is extremely rare. The present study describes a case of CHL in an 11-year-old male presenting with lower back and right hip pain. Radiologic imaging showed a solitary lytic lesion involving the L5 vertebrae and sacrum. Pathologic examination led to a diagnosis of extranodal osseous CHL and further workup proved bone marrow and nodal disease. Diagnosis of extranodal osseous CHL is challenging, especially in this age group and location. When confronted with a solitary lytic bone lesion in a young patient, more common benign and neoplastic entities enter the differential diagnosis and include osteomyelitis, Langerhans cell histiocytosis, epithelioid hemangioma of bone, leukemia, and anaplastic large cell lymphoma (ALCL) among others, with extranodal osseous CHL being one of the less common entities in the differential diagnosis. This case report raises the awareness of extranodal osseous CHL as one of the entities to consider when confronted with a solitary lytic bone lesion in a young patient.

Oligodendrogliomas are a rare type of primary brain tumor. They are genetically defined as diffuse gliomas carrying mutation in isocitrate dehydrogenase type 1 (IDH1) or type 2 (IDH2) and codeletion of chromosomes 1p and 19q. The WHO grading system distinguishes two histopathologic grades of ODs: grade II (low-grade) and grade III (anaplastic oligodendroglioma or AO). These tumors rarely metastasize outside of central nervous system with only few cases reported in the literature. Here we present a case of an AO, which metastasized to the bone marrow and other sites within a year of diagnosis despite aggressive treatment measures. Our patient eventually succumbed to his disease, raising many questions about this rare condition, its natural course and optimal management strategy.

BACKGROUND: Aggressive natural killer cell leukemia/lymphoma (ANKL) is a rare and highly aggressive NK cell neoplasm with a short clinical course and poor prognosis and is often misdiagnosed and confused with NK/T cell lymphoma (NKTL), which has a very different prognosis. Here, we present a case with nasal and bone marrow involvement, provide a literature review and make a differential diagnosis.
METHODS: A 41-year-old male presented nasal congestion pharyngalgia, palatal perforation, high fever and multiorgan dysfunction. Our diagnosis primarily relied on clinical features, the morphology and immunophenotype of the neoplastic cells and imaging studies. Characteristic large granular lymphocytes with azurophilic granules were visible in the bone marrow smears. In addition, the neoplastic cells expressed a typical immunophenotype, and the T cell receptor γ (TCR-γ) gene rearrangement analysis and presence of Epstein-Barr virus (EBV) were negative. The patient\'s symptoms and signs were temporarily relieved after chemotherapy treatment, but after a short time, he underwent a rapid clinical decline and died 8 weeks later after admission due to multiorgan function failure.
CONCLUSIONS: Our case demonstrates that to avoid a misdiagnosis, bone marrow analyses and other examinations should be performed early when a patient initially presents nasal lesions and other systemic symptoms. To the best of our knowledge, this may be the first reported case of ANKL with sternal tenderness.

Precursor B-cell lymphoblastic lymphoma (B-LBL) is an uncommon subtype of Non-Hodgkin lymphoma (NHL), accounting for only 0.3% of NHL in adults and less than 10% of all LBL cases. Unlike T-cell LBL, it usually presents with extranodal involvement while sparing the bone marrow (BM). Among the 27 patients with LBL treated in the Asan Medical Center between January 2007 and March 2012, 3 had B-LBL. All had a good performance status and low International Prognostic Index. However, unlike most previously reported cases, the patients had lymphoma in their bone marrow and extranodal sites such as bone and lung. After intensive combination chemotherapy, one patient achieved a complete response and the other 2 patients, a partial response. Our experience suggests that multiple extranodal sites may be involved in B-LBL and BM involvement may not be as infrequent as previously thought. Furthermore, intensive chemotherapy seems to be effective.