Langerhans Cell Sarcoma: A Case Report Demonstrating Morphological and Immunophenotypical Variability within a Single Lesion

Abstract

Langerhans cells are antigen presenting dendritic cells and tumours arising from these are rare. The tumours arising from these dendritic cells are divided into two categories according to a WHO classification: Langerhans cell histiocytosis and Langerhans cell sarcoma. It is the degree of atypia and clinical aggressiveness that distinguishes the two subtypes. Langerhans cell sarcoma (LCS) is a neoplastic proliferation of Langerhans cells which can occur in skin, bone marrow, lymph nodes, spleen, liver, and lung. LCS can present with multiple cutaneous and systemic lesions. We present a case of Langerhans cell sarcoma with a unique morphological appearance and variable immunohistochemical profile within a single cutaneous lesion. LCS is a rare malignancy and its diagnosis is based on morphology, immunophenotypical examination, and ultrastructural analysis by electron microscopy. Our case highlights a unique morphological description of LCS wherein the pleomorphic neoplastic cells show epidermotropism and are surrounded by a variable amount of inflammatory infiltrate within a single cutaneous lesion. A single cutaneous lesion of Langerhans cell sarcoma with variable immunohistochemical profile has not been described so far.

Langerhans cell sarcoma involving skin and showing epidermotropism: A comprehensive review

“…Based on histopathology and clinical aggressiveness, Langerhans cell tumors can be divided into two main groups: LCH, a cytologically benign proliferation, and LCS, a cytologically malignant proliferation 55 . Both groups preserve the phenotypic and ultrastructural features of Langerhans cells.…”

Left Forearm Langerhans Cell Sarcoma Demonstrated by 18F-FDG PET/CT

“…Diagnosis of primary Langerhans cell sarcoma is difficult, and it is necessary to differentiate it from other malignancies of the skin, including anaplastic large cell lymphoma, 4 malignant melanoma, 5 metastatic cancer, myeloid sarcoma, and malignant fibrous histiocytoma 6 . Langerhans cell sarcoma occurs at any age and involves many organs or tissues, including bone marrow, 7 lung, 8 lymph nodes, 9 liver, 10 skin, 11–13 and subcutaneous tissue 14 . Our case indicated that the differential diagnosis of Langerhans cell sarcoma should be borne in mind for cases with high FDG uptake of skin mass.…”