A rare neoplastic disease characterized by a localized unifocal low-grade tumor composed of mature mast cells without evidence of systemic mastocytosis or skin lesions. The tumor most commonly arises in the lung and shows a non-destructive growth pattern.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version March 2026
Newly diagnosed with
Extracutaneous mastocytoma?
Our RARE Concierge Services Guides are available to assist you by providing information, resources and connections as you navigate your rare disease journey.
Advocacy Organizations
Super T’s Mast Cell Foundation
To increase awareness through resources, education and support for the mast cell diseases community, while also providing financial assistance to patients.
The Mast Cell Disease Society (TMS)
We are dedicated to providing multi-faceted support to patients, families and medical professionals in our community and to leading the advancement of knowledge and research in mast cell diseases through education, advocacy and collaboration.
Don't see your organization here. Let us know here.
Clinical Trials
For a list of clinical trials in this disease area, please click here.