Background: Langerhans cell histiocytosis (LCH) is a proliferating disorder
of Langerhans cells (LC) that are characterized by the presence of Birbeck
granules. LCH has been considered to be a disease of childhood and there h
ave been limited cases of adult LCH. We report here a fatal case of histioc
ytic tumor showing Langerhans cell phenotype, arising in the skin of a 74-y
Method: In addition to routine histological and immunohistological sections
, electron microscopic examination and human androgen receptor gene (HUMARA
) assays were performed.
Results: Histological examination revealed a dense dermal infiltrative prol
iferation of fairly large tumor cells with abundant ill-defined cytoplasms
and oval or indented nuclei, in which numerous eosinophils were associated
with the tumor nests. Tumor cells were positive with and-S-100 and CD1a ant
ibodies but negative with HMB-45 antibody or other epithelial or lymphocyti
c markers. Ultrastructural analysis showed typical Birbeck granules in the
cytoplasm of the tumor cells. HUMARA assay of the tumor tissue revealed the
nonrandom X inactivation pattern, indicating the clonal proliferation.
Conclusions: We diagnosed this tumor as Langerhans cell histiocytosis with
a clonal neoplastic phenotype originated in the skin. Although she demonstr
ated no recurrence nor metastases for 6 months after surgical resection of
primary skin lesion and subsequent radiation therapy, the tumor recurred an
d extended multisystemically, and she died of multiple organ failure 14 mon
ths after initial diagnosis. Therefore, we would like to emphasize this cas
e as LC "sarcoma" or "malignant" LCH.