Chondromesenchymal hamartomas are rare, benign, tumor-like nasal masses in children that have been associated with DICER1 mutations.
The entity is rare: a systematic review of the literature in 2015 identified fewer than 50 reported cases 2. The mean age of presentation is 10 years 2.
Patients most commonly present with nasal congestion or mass on examination 2.
The mass is typically centered in the nasal cavity but commonly also involves the paranasal sinuses, orbit, and/or anterior skull base 2.
Chrondromesenchymal hamartoma was introduced in the World Health Organization classification of head and neck tumors, 4th edition (2016), under the category "Tumors of the nasal cavity, paranasal sinuses, and skull base."
Histology shows nodular hyaline cartilage with a spindle cell stroma 1.
Chondromesenchymal hamartoma is associated with somatic or germline DICER1 mutations 3,4. It is therefore part of the phenotypic spectrum of DICER1 tumor predisposition syndrome.
The imaging appearance is nonspecific, consisting of an expansile, circumscribed sinonasal mass 1.
CT demonstrates polypoid soft tissue in the nasal cavity. There may be osseous erosion, internal calcifications, and cystic components 1.
The signal characteristics reflect myxoid stroma with low cellularity and variable vascularity 5:
- T1: isointense to brain
- T2: heterogeneously hyperintense, with some cystic areas approaching cerebrospinal fluid intensity
- T1 C+: variable enhancement
See the differential for pediatric nasal cavity masses.
- 1. Dean KE, Shatzkes D, Phillips CD. Imaging Review of New and Emerging Sinonasal Tumors and Tumor-Like Entities from the Fourth Edition of the. (2019) AJNR. American journal of neuroradiology. 40 (4): 584-590. doi:10.3174/ajnr.A5978 - Pubmed
- 2. Mason KA, Navaratnam A, Theodorakopoulou E, Chokkalingam PG. Nasal Chondromesenchymal Hamartoma (NCMH): a systematic review of the literature with a new case report. (2015) Journal of otolaryngology - head & neck surgery = Le Journal d'oto-rhino-laryngologie et de chirurgie cervico-faciale. 44: 28. doi:10.1186/s40463-015-0077-3 - Pubmed
- 3. Stewart DR, Messinger Y, Williams GM, Yang J, Field A, Schultz KA, Harney LA, Doros LA, Dehner LP, Hill DA. Nasal chondromesenchymal hamartomas arise secondary to germline and somatic mutations of DICER1 in the pleuropulmonary blastoma tumor predisposition disorder. (2014) Human genetics. 133 (11): 1443-50. doi:10.1007/s00439-014-1474-9 - Pubmed
- 4. Priest JR, Williams GM, Mize WA, Dehner LP, McDermott MB. Nasal chondromesenchymal hamartoma in children with pleuropulmonary blastoma--A report from the International Pleuropulmonary Blastoma Registry registry. (2010) International journal of pediatric otorhinolaryngology. 74 (11): 1240-4. doi:10.1016/j.ijporl.2010.07.022 - Pubmed
- 5. Kim JE, Kim HJ, Kim JH, Ko YH, Chung SK. Nasal chondromesenchymal hamartoma: CT and MR imaging findings. (2009) Korean journal of radiology. 10 (4): 416-9. doi:10.3348/kjr.2009.10.4.416 - Pubmed