Poster
# 87
Poster |
|
6th Internet World Congress for Biomedical Sciences |
Alberto Pizarro Gallardo(1)
(1)Facultad de Medicina U.A.N. - Tepic. Mexico
|
 |
|
|
[Gastroenterology & Hepatology] |
[Pathology] |
In the Gastrointestinal tract the majority of leiomyomatous tumors arise from the muscularis of the stomach and gastric blood vessels. Since leiomyomatous lesions of the alimentary canal sometimes are discovered incidentally at autopsy or during the course of others operations. (1 )
A leiomyomatous mass growing from the wall of the stomach is liable to suffer ulceration and consequently to cause gastrointestinal haemorrhage and anaemia.(1-2) The term " leiomyoblastoma" was proposed by Stout. It is most frecquently seen in the gastric wall but may occasionally be encountered in the intestines, omentum, mesentery, retroperitoneum, uterus, mediastinum, and deeper superficial soft tissues.(1-3) Leiomyoblastoma (bizarre leiomyoma, epithelioid leiomyoma) is an unusual type of smooth muscle tumor wich is biologically benign in most cases, but on rare occasions may behave in a malignant manner and metastasize.(1-4)These neoplasm form solitary,well-defined, but not encapsulated, rounded or lobulated masses which, when small, tend to be localed intramurally; multiple tumors are rare. Growth may take place towards the lumen, resulting in a polypoid mass and is covered by an attenuated mucosa.
Leiomyoblastomas are benign neoplams that occur in the gastrointestinal tract as well as as the mesentery and retroperitoneal region.
The leiomyoblastoma or bizarre smooth-muscle tumor described by Stout(3) in the wall of the stomach may also be seen in the wall of the intestine, the mesentery. (4) Ultrastructural studies confirm the origin of these tumors from smooth-muscle cells, (5,6) and indicatea clse relationship to small arteries and raise the possibitily of an origin from perivascular myocites. (6)
The leiomyoblastoma is a sarcoma of low grade. its prognosis is better because there is not metastases.
We identified one case in the hospital : Centro Médico La Raza IMSS (México DF) Material of case was received unfixed. Tissue for examination by light microscopy was fixed in 10 % neutral buffered formalin embedded in paraffin, and stained with hematoxilin and eosin. Material for electron microscopy was obteined fresh and were fixed in phosphate buffered 5 % glutaraldehyde, postfixed in 1% osmium tetroxide and dehydrated in graded alcohols, embebbed in Epon-araldite 812. One micron thick sections stained with toluidine blue were used to select appropiated areas for study ultrathin sections were stained with uranyl acetate and lead citrate and examed in a Philips EM-300 Trasmission electron microscope.
The variables of study were : type of cell (round o fusiform), type of muscle (smooth or striated), type of nuclei(round, fusiform or irregular), number of nucleoli, giant cell( yes or not) rugous endoplasmic reticulum(yes o not), collagen(yes or not)microtubules (yes or not)and Number of mitoses x 10 high power field. All dates were captured in basedates Access 97 and analysed in Excell 97 and Epiinfo 6.04.
A-45-year-old woman The symptoms had insidiously develop over the preceding few months. He had experienced poorly localized dull pain in the abdomen. Also there was history of nausea, vomiting. Non-tender lymph nodes were palpated. Liver and spleen were not enlarged. No relevant information of family history.
The patient was explored and a neoplam of stomach resected. The mass was firm in consistency and was measuring 5 cm in diameter.figure 1 & 2
Histological appearances.
The tumors cells, was round with clear cytoplasm, may vary greatly insize and shape in different parts of the same tumor.
The cellular morphology of the muscle neoplasm is all homogeneus and the frequency of mitosis was 4 mtoses by 10 hpf, and some areas of fibrosis and degeneration. figure 3 & 4 Ultrastructural studies confirmed the origin of these tumors from smooth-muscle cells, and indicated close relationship to small arteries and raise the possibitily of an origin from perivascular myocites. Fusiform and round cells with many microfilaments. figures5,6,7,7.
The leiomyoblastoma or bizarre smooth-muscle tumor described by Stout(3) in the wall of the stomach may also be seen in the wall of the intestine, the mesentery. (4)
These neoplasm form solitary,well-defined, but not encapsulated, rounded or lobulated masses which, when small, tend to be localed intramurally; multiple tumors are rare. Growth may take place towards the lumen, resulting in a polypoid mass and is covered by an attenuated mucosa.
We recognize that the term "bizarre leimyoma" was formerly applied to stomach tumors with are now termed " leiomyoblastoma", it would seem to be an appropiate descriptive term for tumors under consideration. Evidence that these lesions may be overdiagnosed was leiomyosarcoma resulted in the reclassification of 31 as cellular leiomyoma and 17 as bizarre leiomyomas. The evidence that the tumors are, in fact, benign in convincing since none of the patient developed recurrence, metastasis, or died of disease within five years of treatment.
Microscopic features: the most important feature of leiomyoblastoma is the predominance of large, rounded or polygonal cells with the characteristic perinuclear clear zone in the cytoplams. The nuclei may be pleomorphic with prominent nucleoli.
Ultrastructural studies confirm the origin of these tumors from smooth muscle cells and indicate a clse relationship to small arteries and raise the possibility of an origin from perivascular myocites. The majority of these tumors are benign in character; recurrence, as with most connective tissue neoplams, is possible but metastasis is rare.(5)
We report one case with leiomyoblastoma in stomach with polypoid form and central ulceration.
The histologic lesion identified round muscle cells with clear cytoplasm.
The ultrastructure swown smooth muscle cells with microtubules and myofilaments.
|
|
|
|
|
|
[Gastroenterology & Hepatology] |
[Pathology] |
