Case for diagnosis. Chondroid syringoma.

The chondroid syringoma is a rare benign tumor, also called mixed cutaneous tumor by the presence of epithelial and mesenchymal components, consisting of sweat elements in cartilaginous, collagenous, myxoid or osseous stroma, among others. It mainly affects middle-aged men and is characterized by asymptomatic and slow growing, dermal or subcutaneous nodules. The most common locations are the head and neck. It is rare on the extremities. There are reports of malignant variants predominantly in women, located on the extremities. We report a case of a female patient with a lesion on the toe, with excellent outcome after surgical treatment.

CASE REPORT

A 68-year-old white female patient complained of an asymptomatic nodular lesion on the second left toe, with onset 7 years before and progressive increase in size since then. At physical examination a voluminous nodular lesion was observed, with smooth erythematous surface, telangiectasias and 4cm in diameter (Figure 1). There were no palpable swollen inguinal lymph nodes.

FIGURE 1

voluminous nodular lesion with a smooth erythematous surface with telangiectasias

A lesion biopsy was performed and the histopathological examination revealed cuboidal cell erytheagglomerates with basophilic round nucleus and eosinophilic cytoplasm adjacent to cartilaginous tissue (Figure 2).

FIGURE 2

cuboidal cells agglomerates with basophilic round nucleus and eosinophilic cytoplasm (Fig. 2, full arrow) adjacent to cartilaginous tissue (Fig. 2, empty arrow). HE 200x

A radiography of the left foot revealed increase in soft tissue without bone involvement.

DISCUSSION

In face of the clinical picture the following diagnostic hypotheses were considered: schwannoma, neurofibroma, nodular tenosynovitis, dermatofibroma and dermatofibrosarcoma protuberans. The histopathological examination indicated it was a chondroid syringoma (CS). The lesion was completely excised, with excellent esthetic and functional results (Figure 3).

FIGURE 3

images before and after the lesion was excised

The CS is a benign tumor also called mixed cutaneous tumor due to the presence of epithelial and mesenchymal components.[1-3] In 1961, Hirsch and Helwig were the first to use the term CS to describe the presence of sweat gland elements in cartilaginous stroma.[1-5] It is a rare tumor, with incidence between 0.01 and 0.1%.[3] It affects mainly middle-aged men and is characterized by dermal or subcutaneous nodules, asymptomatic and of slow growth. It is typically located on the head and neck, only rarely on the extremities.[1-7] There have been reports of malignant variants, predominantly in women and located on the extremities.[1,3,5,8] Although our patient was female, with a lesion on the extremity, the histopathological study of the surgical biopsy confirmed its benign nature.

The neoplasm is located in the deep dermis and/or subcutaneous, forming a well defined and symmetrical tumor mass, delimited by fibrous septa. No pleomorphism, atypical mitoses and necrosis are found. It is currently believed that it might have an eccrine or apocrine origin, with the latter being the most common. The epithelial component has apocrine characteristics when it presents tubular and/or ductal structures with cuboidal cells internally and myoepithelial cells externally. In some cases, apocrine decapitation, follicular and sebaceous differentiation foci can be noted. A tumor is considered as having eccrine characteristics when epithelial stroma is composed of diminutive glands, with a single layer of cells, or of small islands of cuboidal cells dispersed in a myxoid or chondroid stroma. However, the differentiation between eccrine and apocrine is not always simple, either by histopathology or by immunohistochemistry. Even by electronic microscopy this differentiation may be unclear. The mesenchymal component is composed of myxoid or densely collagenized areas. The chondroid areas are observed in 59% of the cases. They may also present calcification foci, trabeculae and bone marrow.[1,9]

The treatment of choice of CS is surgical.[1-9] As it is a lobulated type of tumor, it is recommended to include normal tissue margins to ensure that the entire tumor is removed.[3]