Congenital self-healing histiocytosis (Hashimoto-Pritzker): An ultrastructural and immunohistochemical study

Abstract

Congenital self-healing histiocytosis (CSHH) is a rare primary histiocytic skin disorder. Only a few cases have been studied by ultrastructure and immunohistochemistry. Here we report a new case that was investigated using an electron microscope and a panel of monoclonal (MCA) and polyclonal (PCA) antibodies. CSHH cells were found to bear the immunohistochemical phenotype of normal epidermal Langerhans cells (LC) and histiocytosis X (HX) cells (CD1a/c+, CD1b-, CD4+/-, human leukocyte antigen [HLA]-DR/DQ+, S-100+). However, an electron microscope showed a paucity of Birbeck granule (BG)-containing cells. This contrasted with their immunophenotype. This finding, along with other ultrastructural characteristics of CSHH cells, suggests that histologic differences exist between CSHH and HX. However, because no absolute histologic criterion is known that allows unequivocally the differential diagnosis between the two diseases, this distinction currently has to rely on clinical criteria, mainly the regressive course observed within a few months in CSHH. The precise nosologic position of CSHH among other histiocytic syndromes remains unsettled.

Monocyte-derived dendritic cells have a phenotype comparable to that of dermal dendritic cells and display ultrastructural granules distinct from Birbeck granules

“…Thus, it would be interesting to study antigen internalization and processing in relationship with the atypical granules, as well as the influence of different culture conditions and soluble factors, including transforming growth factor ␤, which increases Birbeck granule expression from CD34 precursors [40], on their structure. Similar granules have also been described in vivo in benign LC tumors [41,42], but not in dermal DC to our knowledge, and not in former ultrastructural studies of monocyte-derived DC [18,24]. Here, as well as in former experiments [20], lower concentrations of interleukins were used than in the other studies because they corresponded more to the usual activity ranges [43,44], and because they induced similar levels of expression of CD1a and of costimulatory molecules as higher concentrations of interleukins.…”

Solitary cutaneous dendritic cell tumor in a child: Role of dendritic cell markers for the diagnosis of skin Langerhans cell histiocytosis

“…22 In contrast, depending on the study, only 10% to 30% (or even none) of the dermal tumor cells of CSHRH exhibit these granules. 7,[23][24][25][26] In accordance with these studies, in our case S-100 protein and CD1a-positive tumor cells were negative for Langerin, thereby excluding the presence of Birbeck granules. Therefore the tumor cell cannot definitely be identified as belonging to the LC subset of skin DCs.…”

Signet-ring sinus histiocytosis

“…Our six cases, however, neoplastic histiocytosis, was considered but could not had no history of surgical trauma to the chest wall or be confirmed. 23,24 Therefore, the mechanism of formathe pelvis.…”