Apocrine Hidrocystoma of the Cheek

detected in several cases [4]. In our case, immunohis-tochemical staining for vimentin was not performed. Positivity for vimentin implies that the tumor cells are of fibroblastic lineage. However, we were able to determine that with the satellite to spindle shape of cells. Histopathologically, the tumors appear well-mar-ginated under low-power microscopic examination. The tumor cells are relatively stellate-and spindle-shaped fibroblastic cells separated by a densely fibrous to fibromyxoid matrix. These fibroblasts lack any atypical or hyperchromatic nuclei. Mitotic figures are very rare or absent, and tumor necrosis is not seen. A wide variety of benign fibroblastic soft tissue tumors have been classified as fibroma. Among the entities included in this category are the nuchal fibroma, fibroma of the tendon sheath, sclerotic fibroma of the skin, and calcifying aponeurotic fibroma. Evens recently proposed an additional group-desmoplastic fibroblastoma. A general lack of awareness of this poorly recognized entity may lead to misdiagnosis of other soft tissue neoplasms because of the small number of reported examples. Miettinen and Fetsch [5] analyzed sixty-three cases of desmoplastic fibro-blastoma from the files of the Armed Forces Institute of Pathology. Fifty-two of these cases were originally diagnosed as other tumors, including fibromatosis (n = 18), fibroma (n = 15), neurofibroma (n = 8), nodular fasciitis (n = 3), fibroma of the tendon sheath (n = 3), myxoma (n = 2) as well as chondroma, myo-fibroma, and myxoid lipoma (one case of each). The differential diagnosis of desmoplastic fibroblastoma includes benign, locally aggressive, and low grade malignant soft tissue tumors consisting of relatively uniform stellate-or spindle-shaped cells embedded in a myxocollagenous matrix, such as nodular fasciitis, fibromatosis, fibroma of the tendon sheath, nuchal fibroma, sclerotic fibroma of the skin, neurofibroma, solitary fibrous tumor, and low grade fibromyxoid sarcoma. Although desmoplastic fibroblastoma of the finger can be confused with fibroma of the tendon sheath, the latter is deeply attached to the tendon or tendon sheath. From a histological perspective, fibroma of the tendon sheath is more cellular and less homogeneous. It also differs from desmoplastic fibro-blastoma because of a lobular growth pattern, with the lobules separated by cleftlike vascular spaces [3,5]. In conclusion, we present a rare case of desmo-plastic fibroblastoma that developed on the finger with clinicopathologic and immunohistomchemical features. Typically, this type of tumor has developed as a firm, non-tender, slow growing mass in older males. Complete excision with functional preservation was performed and recurrence was not observed …