Indeterminate cell histiocytosis with naïve cells

Abstract

Histiocytoses are a heterogeneous group of disorders characterized by proliferation and accumulation of cells of mononuclear-macrophage system and dendritic cells. Histiocytoses are categorized according to the cell of origin into Langerhans cell histiocytosis (LCH), Non Langerhans cell histiocytoses and indeterminate cell histiocytosis (ICH). ICH is an extraordinary rare neoplastic dendritic cell disorder that has poorly understood histogenesis and pathogenesis. It is characterized by a proliferation of dendritic cells, which mimic Langerhans cells immunophenotypically (positive for CD1a and S-100 protein), but lack Birbeck granules characteristic of Langerhans cells. Twenty-four year-old Egyptian male was presented with reddish brown chest wall nodule. Clinical, histopathological, immunohistochemical and ultrastructure features are typical for ICH. He was in a good state without any evidence of recurrence or metastasis after 24 months follow up. Peculiar histopathological features were detected in the present case. Many unidentified cells with Hematoxylin & Eosin Langerhans like features showed negative staining for S-100, CD1a, Langerin and CD68. In absence of cellular atypia and mitosis, the infiltrating cells showed epidermotropism that was reported once in ICH as well as neural and perineural invasion that were not previously reported. Therefore we prefer using a tentatively designated diagnosis; dendritic cell tumor, not otherwise specified or newly proposed diagnosis (Indeterminate cell histocytosis with naïve cells) for the present case.

Indeterminate Dendritic Cell Tumor: A Case Report of a Rare Langerhans Cell Lineage Disease

“…Its rarity and resemblance to LCL often cause as diagnostic challenge for pathologists who are not familiar with this entity. Uniform expression of CD1a and S100 protein enables distinction of IDCT from other forms of non-Langerhans cell neoplasms, such as juvenile xanthogranuloma, xanthoma, histiocytic sarcoma, and reticulohistiocytosis [ 7 ]. The differential diagnosis also includes Langerhans cell lineage tumors, such as Langerhans cell histiocytosis (LCH) and Langerhans cell sarcoma (LCS).…”

“…The differential diagnosis also includes Langerhans cell lineage tumors, such as Langerhans cell histiocytosis (LCH) and Langerhans cell sarcoma (LCS). LCH is a rare condition and mostly occurs in childhood [ 7 ]. In cutaneous LCH, the lesions present as papules or plaques [ 3 ].…”

The Non-Langerhans Cell Histiocytoses (Rare Histiocytoses) – Clinical Aspects and Therapeutic Approaches

“…Therapy: If possible, surgical resection or local laser treatment should be performed. Therapy attempts using prednisone or azathioprine did not show convincing results [15,22]. In some severe cases, the combined application of lipid lowering agents was successful [108].…”

A case of S‐100‐negative CD1a‐positive indeterminate cell histiocytosis

“…Histiocytic disorders are a wide range of benign and malignant diseases and can be differentiated based on clinical, pathologic, and immunophenotypic features. Langerhans, non‐Langerhans, and indeterminate cell histiocytoses have been classified according to the origin of the proliferating cells . Indeterminate cell histiocytosis (ICH) is a rare proliferative disorder, characterized by the presence of dendritic cells that share immunophenotypic features with both Langerhans cells (CD1a and S‐100 positivity) and macrophages (CD68 positivity), but lack Birbeck granules .…”

“…Langerhans, non-Langerhans, and indeterminate cell histiocytoses have been classified according to the origin of the proliferating cells. 1 Indeterminate cell histiocytosis (ICH) is a rare proliferative disorder, characterized by the presence of dendritic cells that share immunophenotypic features with both Langerhans cells (CD1a and S-100 positivity) and macrophages (CD68 positivity), but lack Birbeck granules. 2 In this case, we describe a unique case of a child who presented with a cutaneous histiocytosis with histologic features consistent with ICH, however, lacking S-100 expression.…”