[Mycobacterial spindle cell pseudotumor in children: a clinicopathological study of two cases].

Objective: To study the clinicopathologic features, and the diagnosis and differential diagnosis of mycobacterial spindle cell pseudotumor in children. Methods: The clinical data, histopathological features, immunophenotype and special staining of 2 mycobacterial spindle cell pseudotumors were analyzed. The related literatures were reviewed. Results: The age of the two boys was 11 months and 22 months respectively, but their clinical symptoms became apparent at the age of about 4 months. The lesions involved lymph nodes and skin. The first patient also had fever for more than 4 months. Both patients received anti-inflammatory treatment in the outside hospital, but had no obvious improvements of the symptoms. A tumor resection was performed at the outside hospital. Histologically, mycobacterial spindle cell pseudotumor consisted of bland spindle cells, which formed fascicles, without any obvious atypia and mitoses. The cell nuclei were vesicular, with small nucleoli and abundant cytoplasm in some of the cases. The spindle cells expressed histiocyte-associated markers, such as CD68. The Ki-67 proliferation index was low. The mycobacteria were usually readily highlighted by acid-fast staining, which located in the cytoplasm of proliferative spindle cells. In the first case, there was obstructive jaundice because of the progressive enlargement of live portal lymph nodes and systemic disseminated lesions. The second patient had disease recurrence after only operation, and gradually developed other skin nodules and superficial lymph node enlargement. The high-throughput molecular analysis of the skin biopsy confirmed the diagnosis of mycobacterium tuberculosis. After 11 days of anti-tuberculosis treatment, the patient's condition improved significantly. Conclusions: Mycobacterial spindle cell pseudotumor in children is a very rare benign lesion. It is characterized by spindle-histiocyte proliferation caused by mycobacterium infection. An acid-fast stain appears necessary for confirming the diagnosis.

[Clinical and pathological features of 13 children with Epstein-Barr virus-positive lymphoproliferative disease].

Objective: To summarize the clinical characteristics, virological and histopathological features, clinical outcome of Epstein-Barr virus-positive lymphoproliferative disease (EBV(+)LPD) in children. Methods: The clinical and follow-up data of 13 children histopathologically diagnosed as EBV(+)LPD in the Department of Infectious Disease of Beijing Children's Hospital between January 2011 and December 2016 were summarized. Results: Of the 13 patients, 5 were males and 8 females. The median age of disease onset was 6.0 years (range 1.3 to 15.0 years). The median duration between disease onset and diagnosis was 3 months (range 1 to 24 months). All the 13 patients had fever, 9 cases had hepatosplenomegaly and lymphoadenopathy, 4 cases had only lymphoadenopathy, 7 cases had reduced peripheral blood cells, 7 cases had lung involvement, 3 cases had central nervous system involvement, 3 cases had cardiac involvement, 3 cases had intestinal involvement, 2 cases had skin involvement and 1 case had abdominal mass. All the 13 patients underwent whole blood EBV-DNA PCR examination and the copies ranged from 1×10(8)/L to 1×10(11)/L. Pathology of lymph node confirmed 6 cases, skin pathology confirmed 2 cases, lung pathology, ileum mucosa pathology, liver pathology, abdominal mass pathology and bone marrow pathology confirmed 1 case each. Among 13 patients, 9 cases presented with EBV-positive T cell lymphoproliferative disease(EBV(+) T-LPD), 2 cases with hydroa vacciniforme (HV) and 2 cases with EBV-positive diffuse large B-cell lymphoma (EBV(+) DLBCL) . All the patients were followed up for 2 days to 65 months after discharge. Among 9 cases of EBV(+)T-LPD, 1 case died in a short time, 1 case died after evolved to T-cell lymphoma, 2 cases recovered after hematopoietic stem cell transplantation, 1 case recovered after the chemotherapy of hemophagocytic lymphohistiocytosis(HLH) 2004 protocol and 4 cases were stable now. Of 2 cases of HV patients, 1 case died after evolved to HV like lymphoma and the other still have symptoms. Among 2 cases of EBV(+) DLBCL, 1 case died shortly after discharge and the other was still stable after chemotherapy. Conclusions: Chronic recurrent fever, lymphadenopathy and hepatosplenomegaly are the most common clinical manifestations in children with EBV(+)LPD. Involvement of lung, central nervous system, intestinal tract, skin and other organs are also involved frequently. For children with chronic fever of unknown cause and accompanied by lymphadenopathy and (or) hepatosplenomegaly, EBV (+) LPD should be considered highly when the whole blood EBV-DNA load continues to increase significantly, early biopsy of the proliferative lesion should be performed to make a definite diagnosis. The prognosis of EBV (+) LPD is poor, and some evolve to lymphoma, hematopoietic stem cell transplantation is an effective way to treat this disease.