Nasal Chodromesenchymal Hamartoma

Background

Hamartomas of the nasal cavity are rare and usually identified in children. These tumors have been called various names depending upon the histologic components. Hamartomas of the mesenchyme are more common and have been named chondroid, chondromesenchymal, angiomatous, or lipomatous, depending on the preponderant tissue. The epithelial hamartomas comprise such lesions as respiratory epithelial adenomatoid hamartoma, seromucinous hamartoma, or salivary gland anlage tumor of the nasopharynx. Rare instances of respiratory epithelial adenomatoid hamartoma with additional chondro-osseous component have been described and may arise in a child. However, hamartomas of pure epithelial composition has not been recorded in children.

The chondromesenchymal hamartoma was initially described as a series of 7 infantile nasal tumors. The tumors were reminiscent of the mesenchymal hamartoma of the chest wall. Additional single case reports designated as chondroid hamartoma, nasal hamartoma, and mesenchymoma have also been reported, representing the same lesion.

The adjacent paranasal sinuses, especially the ethmoid sinus may be frequently involved. CT and MRI scans may reveal erosion of the surrounding bone and extension to the skull base and orbital region but aggressive bony destruction are not encountered. Intracranial extension through the cribriform plate to the anterior cranial fossa may be present. Presenting signs and symptoms include respiratory distress, feeding difficulties, and otitis media and oculomotor disturbance when the orbit and optic nerve are compressed.

SYNONYMS Chondroid hamartoma
Nasal hamartoma
Mesenchymoma

AGE RANGE-MEDIAN Infancy to 7 years
Most <3 months

LABORATORY/RADIOLOGIC/OTHER TESTS CHARACTERIZATION

Radiographs

CT scan and MRI Nonencapsulated and ill defined, containing both solid and cystic portions, with calcifications frequently seen

HISTOLOGICAL TYPES CHARACTERIZATION

General
Arch Pathol Lab Med 2001;125:400�403

Two examples in a full-term male newborn and a 9-month-old boy

Characterized by a mixture of various mesenchymal elements, including spindle cells, collagen fibers, and irregular islands of osseous and chondroid tissue

Immunohistochemical study showed positivity to vimentin and S100 protein

Ultrastructural examination of case 1 demonstrated fibroblastic and myofibroblastic differentiation in tumor cells

VARIANTS

PROGNOSIS AND TREATMENT CHARACTERIZATION

Prognostic Factors

Survival Benign

Recurrence Recurrence develops after incomplete resection or microscopic deposits of residual tumor

Metastasis No malignant transformation of NMCH has been found

Treatment Local resection through functional endoscopic sinus surgery is recommended when the tumor is localized in nasal cavity
No adjuvant therapy is necessary.

Am J Surg Pathol 1998;22:425�433

Commonly Used Terms

Nasal Cavity

Last Updated 3/2/2001

SYNONYMS	Chondroid hamartoma Nasal hamartoma Mesenchymoma
AGE RANGE-MEDIAN	Infancy to 7 years Most <3 months

LABORATORY/RADIOLOGIC/OTHER TESTS	CHARACTERIZATION
Radiographs
CT scan and MRI	Nonencapsulated and ill defined, containing both solid and cystic portions, with calcifications frequently seen

PROGNOSIS AND TREATMENT	CHARACTERIZATION
Prognostic Factors
Survival	Benign
Recurrence	Recurrence develops after incomplete resection or microscopic deposits of residual tumor
Metastasis	No malignant transformation of NMCH has been found
Treatment	Local resection through functional endoscopic sinus surgery is recommended when the tumor is localized in nasal cavity No adjuvant therapy is necessary.