Female ; Humans ; Immunohistochemistry ; Lung Neoplasms ; diagnosis ; pathology ; Middle Aged ; Myofibroma ; diagnosis ; pathology

Objective: To investigate the clinicopathological features, diagnosis and differential diagnosis of pediatric myofibroma/myofibromatosis of the soft tissue and bone. Methods: All cases of pediatric myofibroma/myofibromatosis of the soft tissue and bone diagnosed between January 2011 and December 2018 were retrieved from the surgical pathology records in the Department of Pathology, Beijing Jishuitan Hospital, Beijing, China. Clinical and radiological data were collected. H&E and immunohistochemistry were used to examine histological and immunophenotypic features and to make the diagnosis and differential diagnosis. The relevant literature was also reviewed. Results: Twenty-eight cases of pediatric myofibroma/myofibromatosis of the soft tissue and bone were respectively collected. The patients' ages ranged from 2 months to 14 years, with a mean age of 7 years. There were 7 females and 21 males. There were 12 cases located in soft tissue, including the finger (n=9), upper arm (n=1) and foot (n=2). There were 14 cases located in the bone of limb, including the femur (n=8), tibia (n=4), clavicle (n=2), fibula (n=2) and radius (n=1). There were 2 cases of myofibromatosis involving multiple bones. Radiology showed lytic lesions in the bone. The proliferation of spindle-shaped myofibroblasts arranged in fascicles with indistinct eosinophilic cytoplasm and bland nuclei, with no pleomorphism and cytological atypia. The characteristic histologic structure was the biphasic nodular growth pattern with cellular and paucicellular regions. The tumors might arrange in a hemangiopericytoma-like pattern. The stroma varied between dense fibrosis and myxoid changes. The reactive new bone formation and inflammatory cell infiltration also existed. Immunohistochemical study showed that the SMA was positive. The surgical resections were performed. One of the patients had tumor recurrence as a result of 11-month follow-up. Conclusions: The pediatric myofibroma/myofibromatosis of the soft tissue and bone is a very rare benign tumor and has a good prognosis. It has a characteristic morphology and its differential diagnosis from other spindle cell tumors could be made with the immunohistochemical analysis.
Child ; Female ; Humans ; Infant ; Male ; Bone and Bones/pathology* ; Diagnosis, Differential ; Leiomyoma ; Myofibroma/diagnosis* ; Myofibromatosis/diagnosis* ; Child, Preschool ; Adolescent

Actins ; metabolism ; Child, Preschool ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Gastrectomy ; methods ; Gastrointestinal Stromal Tumors ; pathology ; Humans ; Immunohistochemistry ; Myofibroma ; metabolism ; pathology ; surgery ; Stomach ; chemistry ; pathology ; surgery ; Stomach Neoplasms ; metabolism ; pathology ; surgery

OBJECTIVETo investigate the clinicopathologic characteristics and differential diagnosis of myopericytoma.

METHODSSix cases of myopericytomas were analyzed by light microscopy and immunohistochemistry (LSAB detection method).

RESULTSTumors from 3 females and 3 males were found on the extremities and chest wall. The ages of these 6 patients ranged from 16 to 58 years. Histologically, all tumors were unencapsulated. The neoplastic cells were oval to spindle shaped with eosinophilic cytoplasm, had a myoid appearance and showd areas of concentric perivascular proliferation around lesional blood vessels which were present with focal myxoid stroma. Morphologically in some cases the tumor overlap myofibroma, hemangiopericytoma or glomus tumor. One tumor was located entirely within the lumen of a vein. In another case, the tumor displayed cellular pleomorphism, mitotic activity, necrosis should be diagnosed as malignant myopericytoma. The neoplastic cells were positive for SMA and negative for CD31, CD34, S-100, and CK.

CONCLUSIONSMyopericytoma is composed of oval to spindle shaped myoid cells with a striking tendeny for concentric perivascular growth. These cells differentiate towards perivascular myoid cells or myopericytes. Extremely rare malignant myopericytoma exist.

Actins ; metabolism ; Adolescent ; Adult ; Diagnosis, Differential ; Female ; Glomus Tumor ; metabolism ; pathology ; Hemangiopericytoma ; metabolism ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Myofibroma ; metabolism ; pathology ; Neoplasms, Vascular Tissue ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

OBJECTIVETo study the clinicopathologic features, immunophenotype and differential diagnosis of plexiform angiomyxoid myofibroblastic tumor (PAMT) of the stomach.

METHODSThe clinical and pathologic findings of 3 cases of PAMT in the gastric antrum were retrospectively analyzed. Immunohistochemical study was carried out and the literature was reviewed.

RESULTSThe age of patients ranged from 31 to 47 years. The male-to-female ratio was 1:2. The clinical presentation included epigastric pain and distension. Endoscopically, the tumor mass protruded into the gastric cavity at the antrum and ranged from 4.5 cm to 8.0 cm in greatest dimension. One of the tumors studied was associated with surface ulceration. Histologically, the tumors were located in the gastric wall. They were composed of bland spindle cells and small vessels arranged in a plexiform or nodular pattern within a myxoid stroma. Immunohistochemical study showed that the spindle cells were consistently positive for smooth muscle actin and muscle-specific actin. There was focal staining for h-caldesmon, desmin in case 3 and focal positive for epithelial membrane antigen, CAM5.2 in case 1. Further, CD10 and progesterone receptor were positive in case 3.

CONCLUSIONSPAMT represents a rare novel mesenchymal tumor of the stomach, with a propensity of gastric antral involvement. The distinctive pathologic features help to differentiate this entity from other benign and malignant tumors.

Actins ; metabolism ; Adenomyoma ; metabolism ; pathology ; Adult ; Antigens, CD34 ; metabolism ; Diagnosis, Differential ; Female ; Fibromatosis, Abdominal ; metabolism ; pathology ; Follow-Up Studies ; Gastrectomy ; methods ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Humans ; Male ; Middle Aged ; Myofibroma ; metabolism ; pathology ; surgery ; Myxoma ; metabolism ; pathology ; surgery ; Proto-Oncogene Proteins c-kit ; metabolism ; Stomach Neoplasms ; metabolism ; pathology ; surgery