Case Report

This is a photomicrograph (Figure 1) of a biopsied asymptomatic skin nodule from the anterior neck of a 45-year-old man. There was no history of trauma or previous surgical procedure in this location. The epidermis is somewhat raised with hyperkeratosis and acanthosis. The upper dermis shows fibrosis. A well-circumscribed dermal tumor nodule shows no extension into the subcutis. The tumor is composed of mature hyaline cartilage with normal chondrocytes within a homogeneous basophilic stroma. The chondrocytes show mostly single small nuclei without any significant atypia (Figure 2). There is no necrosis or mitotic figures. Secondary ossification or calcification is not present. The periphery of the tumor is free of any giant cell reaction, granulation tissue or any evidence of traumatic tissue reaction. The lesion appears to be a true chondroma in the dermis.

Figure 1

Figure 1: Skin biopsy, anterior neck, low magnification.

Figure 2

Figure 2: High magnification.

Comment

Chrondroma cutis is a rarely seen in the dermatology or pathology practice.

One may occasionally see an extraskeletal chondroma occurring in the soft tissue near the small joints of the hands and feet of adults [₁]. These lesions are thought to be originating from the synovial tissue because of their location near the tendon or tendon sheath [₂]. Such lesions have been rarely found in other sites, such as, the head, neck, trunk, oral cavity, larynx, and pharynx [₃]. Benign mixed tumor of the skin, also called chondroid syringoma, may present as a cartilaginous dermal or subcutaneous nodule. However, the tumor is composed of epithelial cords within a chondroid stroma. Rarely, a cartilaginous rest called wattle, probably of branchial cleft origin may be found in the lateral neck of infants. Histologically, the subcutaneous mass is composed of skin with adnexal structures with a central core composed of cartilage and adipose tissue [₄]. In our patient, the benign cartilaginous tumor appears to be a true chondroma cutis. There is no suggestion that the dermal cartilaginous nodule is related to a metaplastic process secondary to trauma or previous surgery. It is located in the dermis of the anterior neck without any connection to the larynx or any other adjacent structure. There is no evidence of thyroglossal or branchial cleft cyst.

Correspondence to

Bo Wang, M.D.
Department of Pathology
Creighton University Medical School
Omaha, Nebraska 68131