Gastric leiomyoblastoma is an uncommon intramural tumor, Its been regarded as a tumor of smooth muscle origin by its histological and electronmicroscopic characteristics. However, recent immunohistochemical staining techniques have shown that tumors diagnosed as leiomyoblastoma may have different tumor origins. We report a case of multiple leiomyoblastoma of the stomach thought to be of unknown derivation by Immunohistochemical study.
Leiomyoma, Epithelioid* ; Muscle, Smooth ; Stomach*

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

A 48 year-old man was admitted with the chief complaint of epigastric pain for 10 days. With upper gastrointetinal series and gastrofiberscopy, there noted a round hemispherical submucosal tumar at lesser curvature side of stomach. Because of continuous epigastric pain and large submucosal mass with mucosal ulceration the patient undewent operation. After subtotal gastrectomy, we found the round well-demarcated tumor with mucosal ulceratian and hemarrhage, which located at muscular layer. Microscopically, dominent cells of tumor are round or polygonal epithelioid cells, which cytoplasm was lightly eosinophilic and was tightly coadenced about nucleus so that the bulk of the cell appeared clear. In the immunohistochemistry with desmin, the tumor cells are positive. Histological diagnosis was leiomyoblastoma of stomach. In 1960 Martin et al. described six cases of unusual round cell myogenic tumor of stomach. In 1962, Stout report a series of 69 similar cases and he proposed the term leiomyoblastoma'. Until recent, leiomyoblastoma are rare and largely misdiagnosed as leiomyoma or leiomyosarcoma. A careful histological study is recommended in case of smooth muscle cell tumor of stomach
Cytoplasm ; Desmin ; Diagnosis ; Eosinophils ; Epithelioid Cells ; Gastrectomy ; Humans ; Immunohistochemistry ; Leiomyoma ; Leiomyoma, Epithelioid ; Leiomyosarcoma ; Middle Aged ; Myocytes, Smooth Muscle ; Stomach ; Ulcer

In 1960 Martin and his associates described another type of tumor of the stomach derived from the smooth muscle, which they named myoid tumor in a study of six patients. In 1962 Stout applied the term "lelomyoblastoma" to this interesting entity in a report of a collected series of 69 patients. Tumor cells are round or polygonal epithelioid cells, which contain perinuclear vacuole or clear zone. A 58 year-old female was admitted to this hospital because of epigastric discomfort for three months. At Upper gastrointestinal series and gastrofiberscope, a round hemispherical submucosal tumor was noted at posterior wall near the lesser curvature of gastric antrum. After subtotal gastrectomy, the submucosal tumor was diagnosed as leiomyoblastoma. Because leiomyoblastoma are rare and easily misdiagnosed as leiomyoma or leiomyosarcoma, careful histologic study is recommended.
Epithelioid Cells ; Female ; Gastrectomy ; Humans ; Leiomyoma ; Leiomyoma, Epithelioid* ; Leiomyosarcoma ; Middle Aged ; Muscle, Smooth ; Pyloric Antrum ; Stomach* ; Vacuoles

Perivascular epithelioid cell tumors (PEComas) refers to a family of mesenchymal neoplasms composed of angiomyolipomas, clear cell “sugar” tumors of the lung, and lymphangioleiomyomatoses. These tumors have a distinctive and common component of perivascular epithelioid cells that show an association with blood vessel walls and immunohistochemically display myomelanocytic differentiation. The unique neoplasms have been shown to have an expanded range through a variety of case reports, including visceral, intra-abdominal, soft tissue, and bone tumors. The retroperitoneum, abdominopelvic region, and uterus have been reported to be the most common sites. Most PEComas follow a benign course. However, reports of malignant PEComas are increasing. Many papers have described uterine PEComas, but to our knowledge, there have not yet been any reports of a malignant PEComa arising concomitant with another epithelial tumor and mesenchymal tumor. We report herein the case of a 67-year-old woman who experienced a malignant uterine PEComa infiltrating a preexisting intramural leiomyoma with synchronous well differentiated endometrial carcinoma and multiple liver and lung metastases.
Aged ; Angiomyolipoma ; Blood Vessels ; Endometrial Neoplasms* ; Epithelioid Cells ; Female ; Humans ; Leiomyoma* ; Liver ; Lung ; Lymphangioleiomyomatosis ; Neoplasm Metastasis ; Perivascular Epithelioid Cell Neoplasms* ; Uterus*

OBJECTIVETo study the pathologic features, diagnosis, differential diagnosis and biologic behavior of uterine perivascular epithelioid tumor.

METHODSFive cases of uterine perivascular epithelioid cell tumor were studied by light microscopy and immunohistochemistry. Follow-up information was reviewed.

RESULTSAll the five tumors were composed by clear or eosinophilic cells arranged in nests and cords, associated with abundant small vessels and hyalinization in the stroma. Immunohistochemically, the tumor cells demonstrated positive staining for melanocytic markers (HMB45 and/or Melan-A), desmin and smooth muscle actin. The staining for cytokeratin and CD10 was negative. All the patients followed for a certain period are still alive, with no evidence of disease recurrence.

CONCLUSIONSPerivascular epithelioid cell tumor is a rare mesenchymal tumor of uterus, with distinctive histologic and immunohistochemical features. It should be distinguished from clear cell carcinoma and epithelioid leiomyoma of uterus. Positivity for melanocytic markers (especially HMB45) plays an important role in the diagnosis of this tumor. In general, the tumor is categorized as benign, with uncertain malignant potential and malignant.

Adenocarcinoma, Clear Cell ; pathology ; Adult ; Antigens, Neoplasm ; metabolism ; Desmin ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Hysterectomy ; methods ; Immunohistochemistry ; Leiomyoma, Epithelioid ; pathology ; Melanoma-Specific Antigens ; Middle Aged ; Neoplasm Proteins ; metabolism ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; surgery ; Uterine Neoplasms ; metabolism ; pathology ; surgery

Actins ; metabolism ; Adult ; Diagnosis, Differential ; Endometrial Neoplasms ; metabolism ; pathology ; surgery ; Endometrial Stromal Tumors ; metabolism ; pathology ; surgery ; Female ; Humans ; Hysterectomy ; Leiomyoma, Epithelioid ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; surgery ; Receptors, Progesterone ; metabolism ; Sarcoma, Clear Cell ; metabolism ; pathology ; Uterine Neoplasms ; metabolism ; pathology ; surgery

Actins ; metabolism ; Adenocarcinoma, Clear Cell ; metabolism ; pathology ; Adult ; Carcinoma, Renal Cell ; metabolism ; pathology ; Desmin ; metabolism ; Diagnosis, Differential ; Endometrial Stromal Tumors ; metabolism ; pathology ; Female ; Follow-Up Studies ; Humans ; Hysterectomy ; Leiomyoma, Epithelioid ; metabolism ; pathology ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Perivascular Epithelioid Cell Neoplasms ; metabolism ; pathology ; surgery ; Receptors, Progesterone ; metabolism ; Uterine Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Actins ; metabolism ; Calcium-Binding Proteins ; metabolism ; Calmodulin-Binding Proteins ; metabolism ; Desmin ; metabolism ; Diagnosis, Differential ; Female ; Humans ; Hysterectomy ; Leiomyoma, Epithelioid ; metabolism ; pathology ; Leiomyomatosis ; metabolism ; pathology ; surgery ; Leiomyosarcoma ; pathology ; Microfilament Proteins ; metabolism ; Middle Aged ; Receptors, Estrogen ; metabolism ; Receptors, Progesterone ; metabolism ; Rhabdoid Tumor ; metabolism ; pathology ; surgery ; Sarcoma, Endometrial Stromal ; metabolism ; pathology ; Uterine Neoplasms ; metabolism ; pathology ; surgery ; Vascular Neoplasms ; metabolism ; pathology ; surgery ; Veins ; pathology ; Vimentin ; metabolism