Epithelioid Leiomyosarcoma Research Articles

Immunoreactivity of paraffin-embedded normal tissues and mesenchymal tumors for smooth muscle myosin.

Immunohistochemical study of smooth muscle myosin, a protein distinct from skeletal, cardiac, or nonmyogenous myosins in paraffin-embedded normal tissues and benign and malignant mesenchymal tumors revealed its strong expression in normal smooth muscle, capillary endothelium, and pericytes. All benign smooth muscle tumors with exception of gastric leiomyomas and few other leiomyomas of the gastrointestinal tract displayed strong or moderate immunoreactivity. On the other hand, strong or moderate immunoreactivity was detected in only eight of 28 spindle-cell leiomyosarcomas, as well as in 13 out of 27 malignant fibrous histiocytomas and three out of nine malignant hemangiopericytomas, while epithelioid leiomyosarcomas, fibrosarcomas, malignant schwannomas, and synovial sarcomas were negative or only weakly positive. Our results demonstrate that, while smooth muscle myosin is a very good marker of normal smooth muscle and benign smooth muscle tumors, it is expressed in diagnostically significant amounts in less than a third of spindle-cell leiomyosarcomas and none of the studied epithelioid leiomyosarcomas.

Pulmonary Metastatic Leiomyosarcoma Coexisting With Pulmonary Chondroma in Carney's Triad

The diagnosis of Carney's triad requires the coexistence of at least two of three rare disorders, including gastric epithelioid leiomyosarcoma, pulmonary chondroma, and functioning extra-adrenal paraganglioma. Seventeen cases have been reported so far, occurring predominantly in young female patients. We report herein the 18th case of this entity and the first case, to our knowledge, where pulmonary metastases from a gastric leiomyosarcoma coexisted in a patient with benign pulmonary chondromas.

Leiomyosarcoma of the gastro-intestinal tract: general pattern of metastasis and recurrence

Clinically, epithelial cancers (squamous cell carcinoma and adenocarcinomas) metastasize primarily by the lymphatic route, while mesenchymal sarcomas more frequently enter the blood stream directly. Nevertheless metastatic involvement of regional nodes has been seen in 13% of patients with soft tissue sarcomas and in 7% of bone sarcomas at initial presentation (29). About one-third of the leiomyosarcomas of the gastro-intestinal tract developed metastasis and about 90% of the metastasis were intra-abdominal (45). Liver is the most common site of metastasis, followed by peritoneal seeding and local recurrence or extension. Regional nodal metastasis also has been noted both initially and subsequently. The most important criterion of diagnosing leiomyosarcoma appears to be the presence of mitosis. Leiomyosarcoma with 1 mitosis per 2 high power fields or epithelioid leiomyosarcoma with 1 mitosis per 5 fields behaved aggressively. Additional criteria useful for diagnosing and for determining prognosis of malignancy include the presence of necrosis, cellular atypia, and the gross size of the tumor. In general, almost all tumors larger than 5 cm in diameter should be viewed with suspicion. For patients with gastric leiomyosarcomas, a proportion, sometimes as high as 14%, had perigastric lymph node involvement at diagnosis (9), and about 7% of those who relapsed had regional nodal metastasis (Table 2). For patients with leiomyosarcoma of the small intestine, about 5% of the patients had nodal metastasis initially, and 9% subsequently (Table 4). Regional lymphatic metastasis also has been reported in leiomyosarcoma of the colorectum. It is believed that wide resection of normal tissues (at least 10 cm margin on either side of tumor) and adjacent mesentery (with routine omentectomy for gastric lesions) not only may discover a higher frequency of occult metastasis in the regional lymph node, but will also decrease the chance of loco-regional relapse and the occurrence of sarcomatosis. As a result of this review and a previous one (30), the surgeon ought to consider when faced with a smooth muscle tumor of the gastro-intestinal tract a wide segmental resection including the adjacent mesentery and omentum, because (a) the precise histologic nature of the lesion (benign vs. malignant) is hard to define even by permanent sections; (b) the possibility of involvement of draining nodes exists and (c) little or no increase in morbidity is anticipated between a wide, as against a limited wedge or segmental resection of gastrointestinal tract. The last point does not need elaboration, except for the very unusual lesions of the duodenum, distal stomach or lower rectum. When adherence to this principle would require a pancreaticoduodenectomy, near total gastrectomy or abdominoperineal resection, it may be wise to establish a definitive histologic diagnosis of the primary lesion first, and to use a more conservative procedure initially.

The triad of gastric epithelioid leiomyosarcoma, functioning extra-adrenal paraganglioma, and pulmonary chondroma

The triad of gastric epithelioid leiomyosarcoma, functioning extra-adrenal paraganglioma, and pulmonary chondroma was found in two young female Mayo Clinic patients, and two of these tumors occurred in another two. Review of the world literature disclosed nine patients who probably had two or more of the three neoplasms. We are also aware of two other patients with two of the three tumors. The association of gastric epitheloid leiomyosarcoma, functioning extra-adrenal paraganglioma, and pulmonary chondroma may well constitute a syndrome because of 1) the improbability of the coincidental occurrence of this triad of tumors, 2) the multicentricity of the tumors in the organs or system affected, and 3) the development of the tumors at a young age. Because two of the components of the triad are potentially lethal, it is important that patients less than 35 years of age who have any one of the three tumors be examined periodically to search for the others.

Gastric epithelioid leiomyoma and leiomyosarcoma (leiomyoblastoma)

A series of 127 surgical specimens of epithelioid leiomyomatous tumors (leiomyoblastomas) of the gastric wall from the files of the Armed Forces Institute of Pathology (AFIP) were studied as to biologic behavior, morphogenesis, and histologic features of value in distinguishing benign and malignant variants. These tumors affect middle-aged men primarily and usually present with upper gastrointestinal bleeding or peptic ulcer-like symptoms. They are composed of a mixture of round epithelioid and spindle cells, many of which have clear cytoplasm. The cells are ensheathed by delicate reticular fibers. The presence of a perithelial or glomoid pattern in some tumors suggests a possible relationship to angiomyoma, glomus tumors, and "pericytoma." The epithelioid leiomyoma, the benign form, often arises in the mid- and distal stomach, especially on the anterior wall. Microscopically, it is recognized by the presence of large epithelioid cells and infrequent mitotic figures. Of 103 epithelioid leiomyomas, only one metastasized and thus was biologically malignant. The epithelioid leiomyosarcoma often arises in the proximal stomach and also distally, especially on the posterior wall. Two histologic types of epithelioid leiomyosarcoma are distinguished from the benign epithelioid leiomyoma by the small size of the cells and occasional higher mitotic counts. One sarcoma variant is a small cell caricature of the leiomyoma. The other is more anaplastic, assoicated with a loss of reticular fibers surrounding the cells and an alveolar arrangement. Epithelioid leiomyosarcomas are the most common type of gastric sarcoma. They are aggressive neoplasms; 63% metastasized, usually within 2 years after diagnosis.

Mesenchymal tumors of the uterus. VI. Epithelioid smooth muscle tumors including leiomyoblastoma and clear-cell leiomyoma: a clinical and pathologic analysis of 26 cases.

Twenty-six cases of atypical smooth muscle tumors of the uterus, including leiomyoblastoma, epithelioid leiomyoma, clear-cell leiomyoma, and plexiform tumorlet, are presented. The characteristic microscopic feature serving as the basis for inclusion in this study is the rounded to polygonal shape of the majority of cells instead of the elongated blunt-ended shape of smooth muscle cells seen in the typical leiomyoma. Mixtures of epithelioid, clear-cell, and plexiform patterns occurred with sufficient frequency to indicate that such patterns are variants of a single entity. A transition to typical smooth muscle cells was found in most instances, confirming the smooth muscle origin of these tumors. Features related to a favorable prognosis include the presence of clear cells, an expansile tumor margin, extensive hyalinization, and absence of extensive necrosis as seen microscopically. Until additional evidence has been accumulated it is proposed that neoplasms having five or more mitotic figures per ten high-power fields (HPF) be tentatively termed epithelioid leiomyosarcoma or leiomyosarcoma with epithelioid features and those with less than five mitotic figures per ten HPF, epithelioid leiomyoma.