Superficial CD34-positive fibroblastic tumor (SCPFT) is a recently described disease entity characterized by marked nuclear pleomorphism, low mitotic count, and diffuse CD34 positivity. It is a rare, distinctive, low-grade fibroblastic neoplasm. To date, only 44 cases have been reported in the English-language literature. Herein, we report two cases of SCPFT involving a 48-year-old male and a 22-year-old male with superficial tumors on the right and left thighs, respectively. Excision was performed in both cases. Histologically, both tumors showed spindle-to-epithelioid cells arranged in fascicular or sheet-like patterns. Most cells displayed granular or eosinophilic glassy cytoplasm, marked nuclear pleomorphism, and a low mitotic rate. On immunohistochemical staining, tumor cells were diffusely positive for CD34 and negative for S100 protein, smooth muscle actin, and desmin. After wide excision, neither patient experienced recurrence or metastasis after 16 months and 11 months of clinical follow-up, respectively. To the best of our knowledge, these are the first two cases of SCPFT reported in Korea. We believe these case reports would contribute to the clinicopathological understanding of SCPFT and assist clinicians in differentiating this tumor from other superficial soft tissue neoplasms.

The aim of this study was to better characterize head and neck solitary fibrous tumors (SFTs) and to evaluate surgical treatment. This retrospective study included patients who presented with head and neck SFTs. Clinical, radiological, and histological information and data regarding the treatments performed were collected. The risk of locoregional and distant metastases was calculated, and for orbital SFTs a specific classification was used. Overall, 34 patients were included. The majority of the SFTs were found in the oral cavity (n = 10), followed by the neck region (n = 8). The mean time to recurrence was 67.4 months. All patients underwent primary surgical resection. Recurrence was observed in five patients with a low risk of locoregional recurrence and distant metastasis. The treatment of choice is complete resection. Recurrence seems to be highly correlated with positive surgical margins. The safety margin should be increased when removing the lesion, and long-term follow-up should be performed.

We report on a 47-year-old woman with unilateral fibrous dysplasia and three intramuscular masses. Medical imaging revealed possible intramuscular myxomas, so that the suspected diagnosis was Mazabraud syndrome. After biopsy, the suspected diagnosis was verified by histology and molecular pathology. Due to endocrine abnormalities in the patient\'s medical history, McCune-Albright syndrome has was also verified.

BACKGROUND: The rare cutaneous solitary fibrous tumor was initially described in the thoracic cavity in relation to the pleura and subsequently been associated with other serous membranes. It has been described in other extraserosal locations including the skin. Knowledge of its existence along with fairly typical histological features and the immunohistochemical expression pattern with intense positivity for CD34 allow the increasing diagnosis of this condition, which suggests that these cases were not previously diagnosed as such.
METHODS: We report the case of a 43 year-old male with a painless nodule in the first left finger pad clinically suggestive of pyogenic granuloma or nodular melanoma, which was diagnosed by excisional biopsy and immunohistochemical study as a solitary fibrous tumor.
CONCLUSIONS: Only 11 cases of cutaneous solitary fibrous tumor have been published in the following locations: head, cheek, thigh, chest, back and nose. Our work describes the first case of cutaneous solitary fibrous tumor in the hand. The solitary fibrous tumor derived from mesenchymal cells expresses CD34 and hence its presentation in any location. In our case it was in the hand. It explains the problems encountered in the clinical differential diagnosis with other tumors as nodular melanoma, pyogenic granuloma, giant cell tumor of tendon sheath, fibroma, benign peripheral nerve sheath tumors, etc. As we consider the histology, differential diagnosis should be made with other tumors that also express CD34.
CONCLUSIONS: Solitary fibrous tumors derived from mesenchymal cells express CD34 and hence its presentation in any location. In our case it was in the finger pad.
Antecedentes: el tumor fibroso solitario es un tumor poco común. Anteriormente se suponía que afectaba sólo la cavidad torácica, en especial la pleura; posteriormente, se relacionó con otras membranas serosas y se observó en diversas localizaciones extraserosas, entre ellas la piel. El conocimiento de este tumor, junto con el aspecto histológico característico y el patrón de expresión inmunohistoquímica con intensa positividad para CD34 permiten que cada vez se diagnostique con mayor frecuencia. Caso clínico: se comunica el caso de un varón de 43 años de edad con un nódulo indoloro en el pulpejo del primer dedo izquierdo, que sugería clínicamente un melanoma nodular o granuloma piógeno. Mediante biopsia excisional y estudio inmunohistoquímico se diagnosticó como tumor fibroso solitario. Discusión: hasta la fecha se han publicado 11 casos de tumores fibrosos solitarios cutáneos, localizados en cabeza, mejilla, muslo, pecho, espalda y vestíbulo nasal. El caso que se comunica constituye la primera lesión de estas características que afecta la mano. El diagnóstico clínico diferencial del tumor fibroso solitario incluye otros tumores como: melanoma nodular, granuloma piógeno, tumor de células gigantes tenosinovial, fibroma y tumor de vaina de nervio periférico benigno. En cuanto a la histología, se planteó el diagnóstico diferencial con otras neoplasias que también expresan CD34. Conclusiones: el tumor fibroso solitario deriva de células mesenquimatosas y expresa CD34, lo que explica su aparición en cualquier localización, como en este caso, que fue en el pulpejo del quinto dedo.