Leiomyoblastoma is uncommon and has been known as a neoplasm of smooth muscle origin. However, with recent pragress in immunohistochemical staining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. We present here a case of gastric leiomyoblastoma did not expressed desmin and neuron specific enolase, and was thought to be of unknown derivation.
Desmin ; Leiomyoma, Epithelioid* ; Muscle, Smooth ; Phosphopyruvate Hydratase

Leiomyoblastoma is uncommon and has been known as a neoplasm of smooth muscle origin. However, with recent pragress in immunohistochemical staining techniques, many clinicopathological discrepancies have been pointed out about the origin of leiomyoblastoma. We present here a case of gastric leiomyoblastoma did not expressed desmin and neuron specific enolase, and was thought to be of unknown derivation.
Desmin ; Leiomyoma, Epithelioid* ; Muscle, Smooth ; Phosphopyruvate Hydratase

Dermatofibrosarcoma protuberans (DFSP) is a slowly growing dermal spindle cell tumor and its myxoid variant, a rare type of DFSP, is characterized by extensive myxoid degeneration. We present the case of a 69-year-old woman with a multinodular reddish plaque on her trunk. Histopathologically, the tumor was located in the dermis and consisted of uniform spindle-shaped cells, showing strongly positive reaction for CD34, and negative for both S-100 and desmin. In addition to the typical storiform pattern, prominent myxoid stromal changes were demonstrated. Herein, we report an interesting case of myxoid DFSP, rarely reported in the dermatology literature.
Aged ; Dermatofibrosarcoma ; Dermatology ; Dermis ; Desmin ; Female ; Humans

We report on a case of angiomatoid fibrous histiocytoma located deep in subcutaneous tissue of the left shoulder in an 11-year-old boy. An ovoid firm mass was slowly increasing in size for 5 months without any pain or tenderness. The tumor was grossly multicystic, with dense fibrous capsule and it measured 7.5 x 7.5 x 4.0 cm. The locules contained hemorrhagic fluid, and the inner surface was purplish brown and trabecular. The septal solid areas were cellular, and they consisted of histiocytoid spindle cells that were arranged in a storiform or fascicular pattern. The tumor cells showed immuno-positivity for CD99, CD68 and desmin. These findings were compatible with angiomatoid fibrous histiocytoma of an uncommon location.
Child ; Desmin ; Histiocytoma, Benign Fibrous* ; Humans ; Male ; Shoulder ; Subcutaneous Tissue

The vagina is an infrequent site of primary sarcomas, which are less than 2% of all malignant vaginal neoplasm. The most common malignant mesenchymal tumor of the vagina is rhabdomyosarcoma, but leiomyosarcoma is rare type tumor of the vagina. Microscopically, spinle cells with pleomorphic nuclei and mitotic figures were frequently noted, but cross-striations were not found in the tissue. Alpha-smooth muscle actin and desmin were positive, but sarcomeric actin was negative in the tumor cells. The authors report a case of primary leiomyosarcoma of the vagina with brief literature review.
Actins ; Desmin ; Leiomyosarcoma* ; Rhabdomyosarcoma ; Sarcoma ; Vagina* ; Vaginal Neoplasms

Fibrous hamartoma of infancy (FHI) is an uncommon benign fibrous proliferation, usually presenting as a single nodule. A 17-month-old male patient had an asymptomatic fingertip-sized subcutaneous nodule on the right side of the back for 6 month. Histopathologic findings showed the typical feature of FHI, that is well defined intersecting fibrous trabeculae, small immature cells within loosely textured areas, and mature adipose areas in the lower dermis and subcutaneous layer. Immunohistochemically, vimentin positivity was present in both the trabecular and loosely textured areas, but desmin was not present in any components which is positive usually only in trabecular areas. The lesion was excised without recurrence. We experienced and report an uncommon case of fibrous hamartoma of infancy in a 17-month-old male patient.
Dermis ; Desmin ; Hamartoma* ; Humans ; Infant ; Male ; Recurrence ; Vimentin

Evaluation of serous effusions can include immunocytochemical stains that differentiate reactive mesothelial cell from adenocarcinoma cell. Among several positive mesothelial cell markers, we used desmin, CK5/6, WT1 and calretinin all known to have high sensitivity and specificity as selective mesothelial cell markers. We studied smears obtained with cytospin from 15 malignant and eight benign effusions. The mesothelial cells were positively stained by desmin, CK5/6, WT1 and calretinin in 60.9%, 29.1%, 26.7% and 56.5%, respectively among 8 benign and 15 malignant effusions; the adenocarcinoma cells were positively stained 6.7%, 13.3%, 1.0% and 0.0%, respectively among 15 malignant effusions. The percentage of positively stained mesothelial cells were somewhat lower for all antibodies compared to the results of previous studies. This was likely due to the differences in preparation methods and fixatives among studies. In conclusion, the use of desmin and calretinin were more valuable than CK5/6 and WT1 for distinguishing between reactive mesothelial cell and adenocarcinoma cells in serous effusion; however, choice of the proper preparation methods and fixatives are also important
Adenocarcinoma* ; Antibodies ; Calbindin 2 ; Coloring Agents ; Desmin ; Fixatives ; Sensitivity and Specificity

PURPOSE: Paraffin-embedded tissue samples from the gastrointestinal tract, which had been diagnosed as tumors of a mesenchymal origin, were reviewed by an immunohistochemical staining method. The prognostic significances of the immunohistochemical subtypes and anatomical locations were also investigated. GIST, as a new grading system, was compared with the pre-existing system for its useful prognostic significance. METHODS: 122 cases were evaluated and classified by immunohistochemical staining for KIT, CD34, actin, desmin, vimentin, S-100 protein and NSE. RESULTS: Positivity for both KIT and CD34 of 92.6 and 73.8%, respectively, indicated that KIT was more effective for the diagnosis of GISTs. The stomach (62.3%) and small bowel (23.7%) were most common organs of GIST. There was no difference in the prognosis between these two organs. Immunophenotypically, the uncommitted, myoid, combined and neural types were 37.7, 23.7, 20.2 and 7%, respectively. There was no significant difference in the prognosis between these types. The old grading system showed no difference between the borderline and malignant groups (P=0.14), whereas, the new grading system showed a significant difference between the intermediate and high risk groups (P=0.01). CONCLUSION: KIT is more useful for the diagnosis of GOSTs. The immunophenotypical classification and anatomical location showed no prognostic significance in GISTs. Therefore, the new grading system might be more useful than older system.
Actins ; Classification ; Desmin ; Diagnosis* ; Gastrointestinal Stromal Tumors* ; Gastrointestinal Tract ; Immunohistochemistry* ; Prognosis ; S100 Proteins ; Stomach ; Vimentin

Plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach is a very rare mesenchymal tumor of the gastrointestinal tract. We report a case of asymptomatic gastric PAMT that was pathologically confirmed after surgical resection. The tumor had a multinodular plexiform growth pattern, bland-looking spindle cells, and an Alcian blue-positive myxoid stromal matrix rich in small blood vessels. Immunohistochemistry analysis revealed that the tumor cells of the PAMT were positive for smooth muscle actin (SMA) and negative for c-kit, CD34, S-100 protein, epithelial membrane antigen (EMA), and desmin. PAMT should be differentiated from other submucosal tumors of the stomach by immunohistochemical findings. Considering the benign features of this tumor, observation without resection may be an option for the treatment of PAMT if the tumor is asymptomatic.
Actins ; Blood Vessels ; Desmin ; Gastrointestinal Tract ; Immunohistochemistry ; Mucin-1 ; Muscle, Smooth ; Myofibroblasts* ; S100 Proteins ; Stomach*

BACKGROUND: Nodular fasciitis presents as a solitary, slightly painful, rapidly growing nodule. It is associated with a reactive, proliferative process of unknown cellular origin and can be misdiagnosed as a sarcoma. OBJECTIVE: Our study was designed to investigate the process and cellular origin of the disease. METHODS: The clinical and histopathologic findings from 28 cases of nodular fasciitis were reviewed. Additional histochemical and immunohistochemical staining was done. RESULTS: The mean age of onset was 29.8 years. A majority of patients with nodular fasciitis had a duration of symptoms of less than 6 months. The upper extremity and face were most frequently involved. Most of the lesions had diameters less than 2 cm. Total excisions were performed in 23 lesions; 3 lesions recurred thereafter. Histopathologically, a subcutaneous plane was most frequently involved. The nodule consisted of numerous large, pleomorphic fibroblasts growing haphazardly in a vascular stroma containing varying amounts of mucoid ground substance, which was confirmed by histochemical stains. In the immunohistochemical stain, most lesions had positive findings for smooth muscle actin (SMA), vimentin and negative findings for CD34 except in a few cases. The stains for desmin and S-100 were negative in all cases. CONCLUSION: It is suggested that nodular fasciitis is associated with a reactive proliferation of myofibroblasts rather than with a sarcomatous process.
Actins ; Age of Onset ; Coloring Agents ; Desmin ; Fasciitis ; Fibroblasts ; Humans ; Muscle, Smooth ; Myofibroblasts ; Upper Extremity ; Vimentin