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Updated: Dec 29, 2025
An Orthotopic Sciatic Nerve Xenograft for Neurofibromatosis Type 1 Neurofibromas
Published on: October 10, 2025
Metastatic acinic cell carcinoma in a neurofibroma mistaken for carcinosarcoma
Michael L Cohn1, Danielle D Elliott, Adel K El-Naggar
1Department of Pathology, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Unit 85, Houston, TX 77030, USA.
Background:
Tumor-to-tumor metastasis is a rare, but well-recognized, entity most commonly involving metastatic carcinoma to a mesenchymal neoplasm. We report a case of acinic cell carcinoma of the parotid gland metastatic to a neurofibroma.
Methods And Results:
A 55-year-old man with a history of a high-grade acinic cell carcinoma of the parotid was seen with a mass at the surgical site and metastatic foci in the scalp 10 months postoperatively. The resection specimen revealed a spindle cell lesion with metastatic foci of high-grade adenocarcinoma, initially diagnosed as a carcinosarcoma. The bland morphology and S-100-positive expression of the spindle cell lesion confirmed the diagnosis of neurofibroma. The high-grade features of the carcinomatous foci and their similarity to the primary tumor confirmed the presence of a tumor-to-tumor metastasis.
Conclusion:
To our knowledge, this is the first reported case of acinic cell carcinoma metastatic to a neurofibroma, an important entity in the differential diagnosis of biphasic tumors of the head and neck.
