Indeterminate-cell histiocytosis: immunophenotypic and cytogenetic findings in an infant.
BACKGROUND
The authors report the immunohistochemical, ultrastructural, and cytogenetic findings in a case of malignant histiocytic proliferation in an infant.


METHODS
The patient presented initially with bone lesions without skin or systemic involvement. Multiple biopsies were studied extensively by immunohistochemistry and electron microscopy. Cytogenetic studies of cell cultures supplemented with granulocyte-monocyte colony stimulating factor (GM-CSF) were also performed.


RESULTS
Morphologically, the cells resembled Langerhans cells, although with greater pleomorphism, as evinced by cells with usual polylobated nuclei. These cells expressed markers for macrophages and antigen presenting cells and were CD1a- and S-100-positive, but lacked Birbeck granules. The cells grown in culture supplemented with GM-CSF showed a unique combination of numerical and structural abnormalities affecting chromosomes 1, 6, 8, and 10. The disease followed a malignant course leading to the patient's demise despite aggressive chemotherapy and bone marrow transplant.


CONCLUSIONS
The findings suggest a malignant hematopoietic stem-cell neoplasm with a capacity for macrophage or dendritic-cell differentiation. Morphology and immunophenotypic features place this neoplasm within the group recently conceptualized as indeterminate-cell histiocytosis.
Martin Flores-Stadler
E
E
Department of Pathology, Children's Memorial Hospital, Chicago, Illinois 60614, USA.
Gonzalez-Crussi
F
F
Greene
M
M
Thangavelu
M
M
Kletzel
M
M
Chou
P M
PM
D002869:Chromosome Aberrations / Q000175:diagnosis; D025063:Chromosome Disorders; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D054747:Histiocytic Sarcoma / Q000235:genetics / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D016130:Immunophenotyping; D007223:Infant; D007621:Karyotyping; D008297:Male; D014411:Neoplastic Stem Cells / Q000145:classification / Q000473:pathology* / Q000648:ultrastructure; D016133:Polymerase Chain Reaction