Rapidly growing nodular fasciitis in the cheek of an infant: case report of a rare presentation.

OBJECTIVE: Nodular fasciitis is a benign proliferative spindle-cell lesion found in the subcutaneous fascia that presents as a rapidly growing mass with rich cellularity and mitotic activity, leading to it frequently being mistaken for a sarcoma. Histomorphologic features and immunohistochemical profile are useful in proper diagnosis. The treatment is complete excision, and recurrence is uncommon. A rare presentation and treatment of nodular fasciitis in the cheek of an infant is described here. METHODS: The lesion was resected by direct transcutaneous approach, and the skin was closed with 2 layers of purse-string polydioxanone sutures followed by fast-absorbing gut sutures to reapproximate the epidermis. RESULTS: Postoperatively, the patient had a wound dehiscence on the cheek, which healed secondarily with wound care. A small area of palpable tumor unable to be resected remained stable after 4 months of follow-up, and facial nerve function was preserved. CONCLUSIONS: Although infrequent in both children and the oral mucosa, nodular fasciitis should be considered in the differential diagnosis of facial tumors in infants and young children.

The C. elegans nuclear receptor gene fax-1 and homeobox gene unc-42 coordinate interneuron identity by regulating the expression of glutamate receptor subunits and other neuron-specific genes.

The fax-1 gene of the nematode C. elegans encodes a conserved nuclear receptor that is the ortholog of the human PNR gene and functions in the specification of neuron identities. Mutations in fax-1 result in locomotion defects. FAX-1 protein accumulates in the nuclei of 18 neurons, among them the AVA, AVB, and AVE interneuron pairs that coordinate body movements. The identities of AVA and AVE interneurons are defective in fax-1 mutants; neither neuron expresses the NMDA receptor subunits nmr-1 and nmr-2. Other ionotropic glutamate receptor subunits are expressed normally in the AVA and AVE neurons. The unc-42 homeobox gene also regulates AVA and AVE identity; however, unc-42 mutants display the complementary phenotype: NMDA receptor subunit expression is normal, but some non-NMDA glutamate receptor subunits are not expressed. These observations support a combinatorial role for fax-1 and unc-42 in specifying AVA and AVE identity. However, in four other neuron types, fax-1 is regulated by unc-42, and both transcriptional regulators function in the regulation of the opt-3 gene in the AVE neurons and the flp-1 and ncs-1 genes in the AVK neurons. Therefore, while fax-1 and unc-42 act in complementary parallel pathways in some cells, they function in overlapping or linear pathways in other cellular contexts, suggesting that combinatorial relationships among transcriptional regulators are complex and cannot be generalized from one neuron type to another.