Munetomo Enjoji

Malignant Fibrous Histiocytoma

A clinicopathologic study of 130 cases of malignant fibrous histiocytoma (MFH) of the soft tissues is reported. This malignant neoplasm principally of middle and late adults occurred most often in the proximal portions of the extremities (48%) including the thigh and buttocks (35%). MFH may be subclassified into common (storiform and pleomorphic), myxoid, xanthogranu‐lomatous, and giant cell types, the common type being accounted for 100 cases (77%) of the series. The prognosis was more favorable in patients with storiform and myxoid tumors than in patients with pleomorphic or other type tumors, the overall relative five‐year survival rate being 48%. The depth of the tumor also affected prognosis with a significantly lower survival rate in deeply situated tumors. The rate of local recurrence of the tumor was 48%. Because of incomplete informations, metastasis was confirmed in only 26 patients and was most frequently to the lung (73%). In addition, electron microscopic, histochemical and tissue culture findings in limited cases are presented, concerning the histogenesis of the MFH.

Angioleiomyoma. A clinicopathologic reappraisal of 562 cases

Five hundred sixty‐two cases of angioleiomyoma in our files on soft tissues were reappraised clinico‐pathologically. There was a preponderance in females with a ratio of 1.7:l. The angioleiomyoma could be separated into three histologic subtypes: capillary or solid (374 cases), cavernous (61 cases), and venous (127 cases) types. Five hundred (89%) occurrences were in the extremities, 48 in the head, and only 14 in the trunk. The tumors caused pain and/or tenderness in 327 cases, in which 262 were of the solid type. In 16 cases, small groups of mature fat cells were demonstrated within the tumor, suggesting the hamartomatous nature of these smooth muscle tumors.

A clinicopathologic and immunohistochemical study of gastrointestinal stromal tumors

The clinicopathologic and immunohistochemical features in 120 cases of gastrointestinal stromal tumor (GIST) were reviewed. Excluding 24 cases of gastric schwannoma, 96 cases of GIST consisting of 62 benign tumors and 34 sarcomas (low grade, 17; high grade, 17), with 9 cases arising in the esophagus, 57 in the stomach, 28 in the small intestine, and 2 in the colon, were studied. All esophagus and colon tumors were benign and resembled a conventional leiomyoma histologically. However, the gastric and small intestine benign tumors mostly showed histologic features of cellular or epithelioid leiomyoma. Immunohistochemically, desmin caused a positive reaction in all esophagus and colon tumors, but only 26% of gastric and small intestine tumors. However, muscle‐specific actin (HHF35) caused a positive reaction in most GIST (92%). The 10‐year survival rates of the patients with gastric sarcoma and those with intestinal sarcoma were 74% and 17%, respectively. These results showed that histologic and immunohistochemical features were distinctly different, depending on the location in the gastrointestinal tract; that most GIST, excluding schwannoma, had smooth muscle differentiation; and that sarcomas had a more favorable prognosis when they occurred in the stomach rather than the intestine. Cancer 1992; 69:947–955.

Gastric carcinoma with lymphoid stroma. Its morphologic characteristics and prognostic correlations

A type of gastric carcinoma was specified under the designation of carcinoma with lymphoid stroma. Grossly, this carcinoma was characterized by clear circumscription, usually with a central ulceration. A histologic feature distinguishing this carcinoma was the presence of a nondesmoplastic stroma infiltrated uniformly with an abundance of lymphocytes and plasma cells throughout the entire area of the tumor. Sparse population of less pleomorphic cancer cell nests of thin trabecular, microalveolar, or primitive tubular pattern widely separated by the intervening stroma was another feature peculiar to this tumor. Carcinoma of this type was found in 4% of a total of 1041 cases of gastric carcinoma removed surgically. A high survival rate was noted among the patients undergoing surgery for this carcinoma. A proposal was made on the separate classification of this tumor from common gastric carcinomas.

Benign Schwannoma of the gastrointestinal tract: a clinicopathologic and immunohistochemical study

A clinicopathologic and immunohistochemical review was made of 24 cases of distinctive nerve sheath tumors located in the gastrointestinal tract. The tumors were microscopically evident in the presence of peripheral lymphoid cuffing and benign nuclear atypia. The tumors arose in the muscularis propria of the stomach in 23 cases and in the ascending colon in 1 case. The patients included 9 men and 15 women whose ages ranged from 36 to 78 years (average, 58). No recurrence has developed in any patient who underwent resection. Although positive immunostaining for S-100 protein, Leu 7 antigen, and laminin might support the schwannian nature of these tumors, the positive immunoreactivity for glial fibrillary acidic protein (GFAP) indicated the possibility of a myenteric plexus origin. The pattern of S-100 protein immunostaining differed from that seen in cases of gastrointestinal stromal tumors associated with von Recklinghausens neurofibromatosis or that noted in cases of conventional leiomyomas. We propose that these tumors be designated as benign schwannoma of the gastrointestinal tract.

Giant cell tumor of the tendon sheath (nodular tenosynovitis): A study of 207 cases to compare the large joint group with the common digit group

Clinicopathologic, enzyme histochemical, and electron microscopic findings in 207 cases (208 lesions) of giant cell tumor of tendon sheath (GCTTS) are presented. The GCTTS could be divided into two groups according to the anatomic location, the first occurring in the digits (digit group, 182 cases) and the second, in the larger joints (large joint group, 25 cases). In the majority of cases of the digit group, the tumor occurred in one of the fingers (158 cases), whereas in the large joint group, the tumor was common in the ankle (10 cases) and knee joints (8 cases). The lesion was more common in women (67%) than in men (33%). Microscopically, the GCTTS in both groups consisted of a mixture of abundant histiocyte‐like, foam, and multinucleated giant cells of the osteoclast type. However, worthy of special mention were the large clefts or wide pseudoglandular spaces lined by synovial cells and that were more striking in the large joint group than in the conventional digit group. The component cells had functional properties of macrophages, as determined in the enzyme histochemical study. Electron microscopically, the tumors consisted essentially of histiocyte‐like, fibroblast‐like, and intermediate cells, together with myofibroblasts.

Nodular fasciitis: an analysis of 250 patients

Summary A clinicopathological analysis was made of data from 250 cases of nodular fasciitis. These benign nodules usually occurred in young and middle‐aged adults in the 4th and 5th decades, most often in the forearm (27%) followed by the thigh (17%) and the upper arm (12%), and grew rather rapidly to reach a mean diameter of 1.5 cm, usually with slight tenderness. Lesions in nodular fasciitis could be separated into 3 types based on a range of histological features, modified from those of Price ef a/.: myxoid, cellular and fibrous. This subgrouping seemed to cover adequately the spectrum of histological appearances observed in nodular fasciitis. It was roughly correlated with the duration of the nodule. The mitotically active myxoid form tended to have the shortest history, the fibrous type the longest, while that of the cellular group was of intermediate duration.

Leiomyosarcoma of the external soft tissues. A clinicopathologic, immunohistochemical, and electron microscopic study

This clinicopathologic study concerns 25 cases of leiomyosarcoma of the external soft tissues, including an immunohistochemical survey of 19 cases and an electron microscopic examination of six. There was a female preponderance in a ratio of 16:9. The most common site of tumors was the thigh (nine cases), followed by the knee (five cases). Three tumors were located in the dermis, 9 were confined down to the subcutis, 2 involved the deep fascia, and 11 involved the skeletal muscle. Superficially located tumors were smaller than deeply located ones. According to the predominant histologic features, the tumors were classified into well (6), moderately (14), and poorly (5) differentiated. In addition to the classical microscopic features, dedifferentiated areas resembling malignant fibrous histiocytoma were noted in three primary tumors and one recurrent tumor. In six tumors, the anatomical location and histologic features were highly suggestive of leiomyosarcoma arising in the venous wall. Many tumor cells immunoreactive for actin were seen in 13 and for desmin in 9 of the 19 cases. Four tumors contained a few tumor giant cells positive for alpha‐1‐antichymotrypsin. Ultrastructurally, the tumors were characterized by smooth muscle tumor cells showing a spectrum of differentiation of varying degrees. In two cases, histiocyte‐like tumor cells were detected. The most reliable prognostic parameter was the depth of the initial tumors; all patients with a leiomyosarcoma confined down to the subcutis are living, most of them more than 5 years after excision, whereas seven of the nine patients with a tumor involving the muscle have died within 5 years after excision.

Malignant neuroepithelioma (peripheral neuroblastoma). A clinicopathologic study of 15 cases.

A clinicopathologic study of 15 cases of malignant neuroepithelioma (peripheral neuroblastoma) of soft tissues is reported. The patients were chiefly young Japanese adults with a median age of 21 years. The tumors arose mainly in the soft tissues of the lower extremity (seven cases) and the trunk (four cases). Microscopically, there were sheets of closely packed, small round or oval cells, and Homer Wright-type rosettes were seen in all cases, one of which also had Flexner-type rosettes. Immunohistochemical cytoplasmic localization of neuron-specific enolase (NSE) was demonstrated in six of the eight cases, using the peroxidase-antiperoxidase (PAP) method. In no case, however, was there any staining reaction for S-100 protein. Of the 14 patients for whom follow-up information could be obtained, nine died within a period of 2 years and two were alive and well for over 5 years after the initial treatment. Differential diagnosis from other soft-tissue round-cell sarcomas, such as embryonal or alveolar rhabdomyosarcoma, extraskeletal Ewings sarcoma, and others, are briefly discussed, on a clinicopathologic basis.

Malignant soft tissue neoplasms with the histologic features of renal rhabdoid tumors: An ultrastructural and immunohistochemical study

Five round cell neoplasms of the soft parts that histologically resembled malignant rhabdoid tumors of the kidney were studied. The tumors were composed mainly of poorly differentiated round or, sometimes, polygonal cells, with a minority of elongated cells; the cytoplasm of many of the cells contained filament-laden acidophilic inclusions. Ultrastructurally, the intracytoplasmic structures were seen to consist of aggregates of 10-nm intermediate filaments, and immunohistochemical staining revealed the presence of cytokeratin and vimentin. All five patients with this tumor had an aggressive clinical course; three of the patients died shortly after the initial diagnosis. As this tumor does not seem to be linked to any known entity, it is referred to as malignant rhabdoid tumor of the soft parts and could be a heterogeneous entity.