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Clinicopathological observation of adult malignant ectodermal mesenchymoma: A case report and literature review
Le Xie1,2, Yingxin Huang1,2, Rongjun Mao1,2
1Department of Pathology, The Eighth Clinical Medical College of Guangzhou University of Chinese Medicine, Foshan, Guangdong, China.
Rationale:
Malignant ectomesenchymoma (MEM) is a relatively rare soft tissue tumor, which predominantly occurs in infants or children under 15 years of age. The classic sites of occurrence are the pelvic perineal region and genitourinary system. Compared to pediatric cases, adult cases exhibit certain differences in clinicopathological features and are more prone to misdiagnosis. A thorough comprehension of their clinicopathologic features is crucial for precise diagnosis and effective management.
Patient Concerns:
A 23-year-old male had a lesion located on the right side of his head and face, and the disease course lasted 13 months. A retrospective analysis was conducted on the clinicopathological data, histopathological features, immunophenotype, and molecular pathological changes.
Diagnoses:
The tumor was composed of embryonal rhabdomyosarcoma and undifferentiated neuroectodermal components. Immunohistochemistry showed positivity for rhabdomyosarcoma markers such as Desmin, MyoD1, and Myogenin in the rhabdomyosarcomatous component and positivity for neuroectodermal markers, including synaptophysin and chromogranin A in the neuroectodermal component. No specific molecular alterations were detected in genetic testing.
Interventions:
This is a case of initial misdiagnosis, multimodal comprehensive treatment combining surgery with chemotherapy was the primary therapeutic approach, However, poor clinical outcomes were observed.
Outcomes:
Despite aggressive treatments, the patient died of the disease after 1 year of follow-up.
Lessons:
Adult MEM is a biphenotypic sarcoma composed of rhabdomyosarcoma and neuroectodermal tissues. Morphological and immunohistochemical interpretation is crucial for diagnosis. treatment approaches and prognosis are correlated with the completeness of tumor resection and the differentiation degree of both components.
Insights
Malignant ectomesenchymoma (MEM) is a rare adult soft tissue tumor. This case highlights diagnostic challenges and poor outcomes despite multimodal treatment, emphasizing the need for accurate diagnosis and tailored management strategies.
Area of Science:
- Oncology
- Pathology
- Soft Tissue Tumors
Background:
- Malignant ectomesenchymoma (MEM) is a rare soft tissue tumor primarily affecting children.
- Adult MEM cases present distinct clinicopathological features and are prone to misdiagnosis.
- Accurate diagnosis and understanding of clinicopathologic features are vital for effective management.
Purpose of the Study:
- To present a case of adult malignant ectomesenchymoma.
- To analyze the clinicopathological, histopathological, and immunophenotypic characteristics of adult MEM.
- To discuss the diagnostic challenges and treatment outcomes in adult MEM.
Main Methods:
- Retrospective analysis of a 23-year-old male patient with a head and face lesion.
- Histopathological examination and immunohistochemistry for rhabdomyosarcoma and neuroectodermal markers.
- Review of clinicopathological data, immunophenotype, and molecular pathological changes.
Main Results:
- The tumor exhibited a biphenotypic composition of embryonal rhabdomyosarcoma and undifferentiated neuroectodermal components.
- Immunohistochemistry confirmed positivity for specific markers of both rhabdomyosarcoma (Desmin, MyoD1, Myogenin) and neuroectodermal (synaptophysin, chromogranin A) tissues.
- No specific molecular alterations were detected.
- Despite multimodal treatment including surgery and chemotherapy, the patient experienced poor clinical outcomes and died within one year.
Conclusions:
- Adult MEM is a biphenotypic sarcoma requiring precise diagnosis through morphological and immunohistochemical evaluation.
- Treatment approaches and prognosis are influenced by the completeness of surgical resection and the differentiation degree of both neoplastic components.
- This case underscores the challenges in diagnosing and treating adult MEM, highlighting the importance of comprehensive clinicopathological assessment.
