PMC9523168_01
Cervical lymph node biopsy and bone marrow aspiration. The aspiration smears of bone marrow show myeloblastic cells accounted for 53.5% (A) and monoblastic cells accounted for 13.8% (B), whereas dendritic cell-like atypical cells are also found at a frequency of 9.1% (C). On bone marrow pathology, CD1a (D)- and S-100 (E)-positive atypical cells accounted for 10% of the blasts. Cervical lymph node biopsy specimen shows atypical cells with indented or folded nuclei like one indicated by arrowhead or other ones with mild folding (F), and immunostaining was Langerin-partially positive (G), S-100-positive (H), CD1a-positive (I), MPO-negative (J). Around the atypical cells were scattered mononuclear cells positive for CD3 (K), CD20 (L), and CD68 (M) in the periphery.
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Whereas, 9.1% of cellular components were occupied by MPO-negative atypical dendritic cell-like cells ( Figures 1A-C ). A biopsy specimen from a cervical lymph node demonstrated the accumulation of atypical round or horseshoe-shaped cells with indented or folded nuclei which were positive for S-100 and CD1a, and negative for MPO and CD34, confirming the diagnosis of LCH ( Figures 1F, H-J ). Atypical cells were partially positive for langerin ( Figure 1G ), not suggestive of indeterminate cell histiocytosis (ICH). Around the atypical cells were scattered mononuclear cells positive for CD3, CD20, and CD68 ( Figures 1K-M ).
The timeline of diagnosis and treatment.
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Subsequently, from day 253, the patient received low dose cytarabine and etoposide, which did not give rise to a durable response, and she died from pneumonia and septicemia on day 384 (Figure 2).