| Abstract [eng] |
Anaplastic lymphoma kinase (ALK)-mutated tumors of the skin represent a rare and heterogeneous group of mesenchymal neoplasms that present significant diagnostic challenges due to their overlapping morphology and immunophenotypic features. This thesis aims to provide a structured overview of their histopathological morphology, molecular genetics, clinical implications, diagnostic approaches, and therapeutic aspects. The structured literature review was conducted using PubMed and Google Scholar, focusing on studies on ALK-positive neoplasms and their diagnostic strategies. Key diagnostic modalities, including immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and next-generation sequencing (NGS), were evaluated for their utility and limitations. In addition, it examines key entities, including inflammatory myofibroblastic tumor (IMT), epithelioid fibrous histiocytoma (EFH), and epithelioid inflammatory myofibroblastic sarcoma (EIMS). The case report describes a 22-year-old female presenting with a spindle cell tumor of the neck. Initial histopathological and immunohistochemical findings suggested a low-grade mesenchymal neoplasm, but a definitive diagnosis remained uncertain due to overlapping features with other entities. In the end, a TPM3::ALK fusion was identified with genetic testing, supporting the diagnosis of an ALK-rearranged tumor most consistent with an inflammatory myofibroblastic tumor. No recurrence or metastasis was observed during 2-year follow-up after complete surgical excision. The findings underscore the important role of genetic and molecular testing in the diagnostics and classification of ALK-positive neoplasms. Although immunohistochemistry is a valuable screening tool, it can yield false-positive or false-negative results, which require confirmation through molecular testing such as fluorescence in situ hybridization or next-generation sequencing, especially in cases of unresectable or advanced disease. In conclusion, the expanding spectrum of ALK-rearranged neoplasms requires a structured diagnostic approach, including histopathological, immunohistochemical, and molecular data. Improved characterization, classification, and long-term follow-up data are essential to refine diagnostic criteria and optimize treatment strategies for these rare tumors in the future. |
