Myxoid liposarcoma and pleomorphic liposarcoma: cyto-histological correlations

Myxoid liposarcoma and pleomorphic liposarcoma: cito-histological correlations. A correlative cytologic and histologic study of a myxoid liposarcoma of the shoulder in a 72 year-old man and a pleomorphic liposarcoma observed in the retroperitoneum of a 84 year-old woman, are presented. A preoperative FNAB cytology performed in both cases showed necrotic material containing spindle-stellate shaped cells, interspersed in a myxoid matrix, with rare classical monovacuolated lipoblasts and fragments of plessiform vessels were seen in the first and scattered pleomorphic and multinucleated cells, with prominent nucleoli and numerous atypical mitosis in the second. A malignant mesenchimal spindle-cells tumor, with myxoid matrix and pleomorphic cells, consistent with liposarcoma, respectively were suspected. Gross and histological specimens confirmed the cytological suspect. Authors discuss main cyto-histological differential diagnoses of myxoid tumors, and point out the importance and a correct differentiation between myxoid liposarcoma and intramuscular myxoma. The cytologic appearance of pleomorphic liposarcoma is similar to histologic type and therefore the problem of a differential diagnosis with soft tissue tumors is analogous. When mono or plurivacuolated lipoblasts are absent, differential diagnosis between pleomorphic histiocytoma and liposarcoma is impossible. Nevertheless this is not a important problem at cytological level because both tumors have a had prognosis and must be treated with radical surgery. Definition of correct histologic type will be more suitable on histologic specimens.     

A light and electron microscopic study with comments on their relation to malignant fibrous histiocytoma and angiosarcoma

Analysis of 365 cases of malignant soft tissue tumors revealed 83 cases of liposarcoma. The ages of the patients were distributed between 18 and 86 years with a mean average of 54.3 years. Approximately 50% of the cases were located in the lower extremity. Histologically, they consisted of 5 types; well differentiated (17 cases), myxoid (49 cases), round cell (3 cases), pleomorphic (11 cases), and mixed (3 cases). The appearance of lipoblasts of either the signet-ring type or mulberry (multivacuolated) type with displaced nuclei was the common characteristic feature for all types. Electron microscopically, lipid droplets were found inside of endoplasmic reticulum in lipoblasts, and abundant glycogen granules were seen in the cells containing only few lipid droplets. The lipoblasts were usually located close to the vascular wall in the interstitium, and findings suggesting an intimate relation between pericytes and lipoblasts were encountered. Although the differential diagnosis of malignant fibrous histiocytoma and liposarcoma was made possible by the appearance of lipoblasts in the latter, storiform pattern and histiocyte-like cells sometimes appeared in poorly differentiated liposarcoma. This tendency was also found in angiosarcoma. A close follow-up of recurrent cases revealed that there are actually cases of liposarcoma with malignant fibrous histiocytoma-like pattern and angiosarcoma with malignant fibrous histiocytoma-like pattern. It was considered that malignant fibrous histiocytoma-like figures can appear in various poorly differentiated sarcomas.     

S-100 protein distribution in liposarcoma An immunoperoxidase study with special reference to the distinction of liposarcoma from myxoid malignant fibrous histiocytoma

The presence and distribution of S-100 protein were studied in 63 cases of liposarcoma and 20 cases of myxoid malignant fibrous histiocytoma (MFH), using the immunoperoxidase technique. Normal adipose tissue and benign lipomatous tumours were also studied by the same technique, for purposes of comparison. In all liposarcomas, most of the adipocytes and vacuolated lipoblasts were positive for S-100 protein, although the tumour cells in non-lipogenic areas of dedifferentiated liposarcoma and the non-vacuolated giant cells with a deeply eosinophilic cytoplasm in the pleomorphic liposarcomas were devoid of S-100 protein immunoreaction products. One third of the myxoid type liposarcomas contained numerous immunoreactive, immature-appearing spindle or oval cells, reminiscent of the primitive fat organs of white adipose tissue. Conversely, none of the myxoid MFHs contained S-100 protein in the tumour cells, including the irregularly vacuolated ones. These results suggests that the immunohistochemical demonstration of S-100 protein is a useful diagnostic tool, particularly for the assessment of vacuolated tumour cells and for the diagnosis of myxoid tumours.     

Fine-needle aspiration in liposarcoma: cytohistologic correlative study including well-differentiated, myxoid, and pleomorphic variants

We have reviewed cytopathology and the corresponding histopathology material of 86 liposarcomas (55 patients) seen at Institut Curie. The liposarcomas (LS) were well differentiated in 14 cases (9 pure, 2 dedifferentiated, 3 sclerosing), 64 myxoid, and 8 pleomorphic. Twenty-four tumors were primary, 34 recurrent, and 28 secondary. Smears in LS were composed in different proportions of round, spindle cells, lipoblasts, and myxoid and vascular arborizing structures. Pure well-differentiated LS were frequently composed of lipoblasts, and round or spindle cells were occasionally seen. Dedifferentiated and sclerosing liposarcomas were composed of spindle or round cells, but lipoblasts were also occasionally present. Myxoid or vascular arborizing structures were absent. Myxoid LS (including round and spindle cell LS) frequently showed a myxoid background and less frequently vascular arborizing structures. Tumor cells were round or spindle. Lipoblasts were also seen. Pleomorphic LS were composed of an admixture of all cellular and stromal elements. Well-differentiated LS should be distinguished from hibernoma and spindle cell lipoma, and myxoid LS from myxoma, myxoid chondrosarcoma, chordoma, myxoid leiomyosarcoma, and myxoid malignant fibrous histiocytoma. The demonstration of the specific translocation t(12;16)(q13;p11) of myxoid LS is very helpful to establish the diagnosis. Pleomorphic LS should be differentiated from other high-grade sarcomas, whenever possible.     

“Dedifferentiated” chordoma: A case report of the cytomorphologic findings on fine-needle aspiration

Chordomas are relatively rare neoplasms occurring at both ends of a neuro axis. The majority follow an indolent course of multiple local recurrences, ultimately leading to the patient's death. Rare examples have been associated with sarcomatous components, usually resembling malignant fibrous histiocytoma, fibrosarcoma, or osteosarcoma. These tumors have followed a more aggressive course, with poor response to treatment and death following a relatively short time course. Cytologic material from a single case obtained by fine-needle aspiration revealed a high-grade malignancy composed of short atypical spindle cells containing modest amounts of granular cytoplasm. Physaliphorous cells were absent, and myxoid material was not a significant component of the smears. Rare polygonal cells with foamy cytoplasm were identified. Histologic study revealed a high-grade spindle-cell sarcoma in which were scattered small aggregates of vacuolated cells resembling physaliphorous cells. Anaplastic giant cells were present, and the overall appearance of the neoplasm resembled a malignant fibrous histiocytoma. Despite the radiographic appearance of a conventional chordoma in this case, the cytologic findings were indicative of a high-grade sarcoma consistent with a dedifferentiated chordoma. Diagn. Cytopathol. 1998;19:378–381. © 1998 Wiley-Liss, Inc.     

Cytopathological dilemma of anaplastic sacral chordoma with radiological and histological corroboration

Chordoma is a relatively rare locally invasive and potentially malignant tumor of fetal notochord origin, affecting the axial skeleton. Cytopathological diagnosis of chordoma is favored by the presence of characteristic physaliphorous cells, bearing abundant foamy cytoplasm dispersed in a myxoid matrix. Anaplastic chordoma or dedifferentiated chordoma, an even rarer variant, can cause a diagnostic confusion with chondrosarcoma from the cytopathological point of view, with similar chondromyxoid matrix and atypical cells. Hence, chordoma bearing anaplastic features needs to be identified and should be distinguished from chondrosarcoma on aspiration cytopathology. We present a case of anaplastic sacral chordoma in a man 59 years of age, causing extensive destruction of sacrum and invading the paravertebral tissues as evidenced by radiology. Fine needle aspiration cytopathology revealed few large pleomorphic hyperchromatic cells, admixed with characteristic physaliphorous cells and myxoid matrix. The cytopathological diagnosis has been confirmed by histopathology and immunohistochemistry. Since anaplastic chordoma bears an unfavorable prognosis, it should be suspected on preoperative aspiration cytopathology. Clinicoradiological correlation along with histopathological and immunohistochemical confirmation is necessary subsequently.     

Comparative fine-needle aspiration and pathologic study of malignant fibrous histiocytoma: cytodiagnostic features of 95 tumors in 71 patients

To determine diagnostic cytomorphologic features of malignant fibrous histiocytoma (MFH) on fine-needle aspiration (FNA) materials, we reviewed the cytologic material and corresponding histologic slides of 95 tumors in 71 patients. Forty-four (46%) tumors were primary, 38 (40%) were recurrent, and 13 (14%) were metastatic. Histological variants of MFH were as follows: 52 (54.7%, 43 patients) were of the storiform/pleomorphic, seven (7.4%, five patients) were giant cells, four (4.2%, four patients) were inflammatory, and 31 (33.7%, 19 patients) were myxoid type. Review of original cytology reports showed that only 23 (24.2%) tumors were diagnosed as MFH and 68 (71.6%) as other types of malignancies. Four (4.2%) cases were reported as unsatisfactory/suspicious. Our findings showed that spindle-shaped, round, giant cells, osteoclastic-like giant, and inflammatory cells were the most consistent features that allow identification of the storiform/pleomorphic, giant cell, and inflammatory variants of MFH. The myxoid tumors had marked myxoid background matrix with spindle-shaped cells and, less frequently, round and giant cells. Pleomorphic leiomyosarcoma and dedifferentiated liposarcoma should be considered in the differential diagnosis of stroriphorm/pleomorphic, giant cells, and inflammatory variants of MFH. However, myxoid MFH may resemble their leiomyosarcoma and liposarcoma counterparts.     

Diagnosing intramuscular myxoma by fine-needle aspiration: A multidisciplinary approach

The gross and microscopic appearances of aspirates from ten intramuscular myxomas are reported. The specimens were obtained from seven women and three men, ages 43 to 75, who had tumors involving the muscles of the thigh (7), upper arm (2), and forearm (1). Magnetic resonance (MR) imaging performed in six of the ten cases revealed well-defined, sharply demarcated tumors exhibiting low signal intensity relative to muscle on the T1-weighted images. The tumors were hyperintense to muscle on T2-weighted images. All aspirated tissues were clear, tenacious, and viscous. Smears contained few spindled and histiocytoid cells in an abundant mucoid background. Spindle cells demonstrated long cytoplasmic processes that in areas intertwined to form fibrillar tangles. Nuclei were oval to spindled with fine chromatin and inconspicuous nucleoli. Capillaries were sparse with simple (nonplexiform) branching. The differential diagnosis of myxoid lesions of the extremities includes benign entities such as myxoid schwannoma and neurofibroma, mesenchymal repair, and ganglion cyst, as well as malignant neoplasms such as myxoid liposarcoma, fibrosarcoma, malignant fibrous histiocytoma, and extraskeletal chondrosarcoma. The findings of this study revealed that, although the cytologic features were suggestive of intramuscular myxoma, a definitive diagnosis was often difficult, owing to scant cellularity and lack of distinctive cytologic features. The MR imaging findings may be utilized as an adjunct to the cytologic features to more confidently suggest a diagnosis of intramuscular myxoma. Diagn Cytopathol 1994;11:255–261. © 1994 Wiley-Liss, Inc.     

Cytologic differential diagnosis of myxoid and mucinous neoplasms of the sacrum and parasacral soft tissues

A diagnostically important group of lesions involving the sacrum, spinal canal, and parasacral soft tissues is characterized by a myxoid or mucinous background in cytologic smears. This group of myxoid/mucoid neoplasms includes chordoma, myxopapillary ependymoma, metastatic mucinous adenocarcinoma, and extraskeletal myxoid chondrosarcoma. Despite the similarity of the background substance, each neoplasm within this differential diagnosis has a characteristic composite set of morphologic and immunophenotypic features. Because many of these masses are not easily surgically biopsied, fine-needle aspiration (FNA) is often used for their diagnosis. The private consultation records of the author and the cytology files of the University of Utah Department of Pathology were searched for all lesions arising in or around the sacrum. These cases were reviewed to determine which had a myxoid/mucinous background. Fourteen neoplasms were found and comprise the study set. Four of these cases had cell block material in addition to Diff-Quik-stained smears; a panel of antibodies, including cytokeratin, glial fibrillary acid protein (GFAP), S-100 protein, and carcinoembryonic antigen (CEA), was performed on the cell block material. The smears were evaluated for cytologic features, including the presence of rosette-like structures, physaliphorous cells, gland-like structures, chondroid fragments, "signet ring" and "goblet" cells, as well as the character of the myxoid/mucinous background substance.The cases included one myxopapillary ependymoma, 10 chordomas, two mucinous adenocarcinomas of colonic or gastric origin, and one myxoid chondrosarcoma. Physaliphorous cells were found to be highly specific for chordoma, while a fibrillary myxoid stroma containing cells with elongated cytoplasmic processes and cells lying in a rosette-like pattern around central cores of myxoid to fibrillary stroma were highly characteristic of myxopapillary ependymoma. Fragments of a myxoid/chondroid matrix with lacunar-like spaces strongly supported the diagnosis of myxoid chondrosarcoma. "goblet" or "signet ring" cells with a single distinct vacuole favored mucinous adenocarcinoma. There appear to be sufficient cytomorphologic features present within the FNA smears and cell block material to allow cytologic separation of the more common myxoid and mucinous neoplasms involving the sacral and parasacral tissues.     

Fine needle aspiration cytology of myxoid lesions of soft tissues: a study of 24 cases

OBJECTIVE: To summarize the diagnostic features of fine needle aspiration cytology (FNAC) of myxoid lesions in soft tissue, and to define the cytological criteria for differentiating benign lesions from sarcomas and between various myxoid lesions. METHODS: FNAC data of 24 soft tissue myxoid lesions (14 benign lesions, 10 malignant lesions) from 1993 to 2006 from Kiang Wu Hospital, Macau were reviewed in correlation with the clinical course or the results of biopsy. RESULTS: Ganglion, myxoma, and myxoid nodular fasciitis were the most common benign myxoid lesions of the soft tissues, all of which had low cellularity and lack of marked cellular atypia in smears in common. Ganglion was characterized by the disappearance of or the gradual minimization of the nodule after aspiration and the lack of blood vessel in smears. Myxoid nodular fasciitis was characterized by a pleomorphic pattern of proliferative cells and the presence of ganglion cell-like cells. Myxoid liposarcoma, extraskeletal myxoid chondrosarcoma and myxofibrosarcoma were the most common myxoid sarcomas. Cytologically, they had high cellularity and various degrees of cellular atypia. Myxoid liposarcoma exhibited branching chicken-wire like capillary vessels and/or lipoblasts; myxofibrosarcoma were prominent in both pleomorphic and atypia of the cells. The data revealed that the diagnostic accuracy of FNAC was nearly 100% in differentiating benign and malignant myxoid lesions of the soft tissues. The coordinate rate to the histopathology diagnosis of the common myxoid lesions of the soft tissues was above 75% (benign 71.4% and malignancy 80% respectively). CONCLUSIONS: FNAC is an effective method in diagnosing myxoid lesions of soft tissue, in correlation with the clinical data and the accessory examinations. FNAC can provide an objective basis for the treatment of myxoid lesions and prevention of unnecessary surgical operations.     

LIPOSARCOMA

Analysis of 365 cases of malignant soft tissue tumors revealed 83 cases of liposarcoma. The ages of the patients were distributed between 18 and 86 years with a mean average of 54.3 years. Approximately 50% of the cases were located in the lower extremity. Histologically, they consisted of 5 types; well differentiated (17 cases), myxoid (49 cases), round cell (3 cases), pleomorphic (11 cases), and mixed (3 cases). The appearance of lipoblasts of either the signet-ring type or mulberry (multivacuolated) type with displaced nuclei was the common characteristic feature for all types. Electron microscopically, lipid droplets were found inside of endoplasmic reticulum in Hpoblasts, and abundant glycogen granules were seen in the cells containing only few lipid droplets. The lipoblasts were usually located close to the vascular wall fn the interetitium, and findings suggesting an intimate relation between pericytes and lipoblasts were encountered. Although the differential diagnosis of malignant fibrous hietiocytoma and liposarcoma was made possible by the appearance of lipoblasts in the latter, storiform pattern and histiocyte-like cells sometimes appeared in poorly differentiated liposarcoma. This tendency was also found in angiosarcoma. A close follow-up of recurrent cases revealed that there are actually cases of liposarcoma with malignant fibrous histiocytoma-like pattern and angiosarcoma with malignant fibrous histlocytoma-like pattern. It was considered that malignant fibrous histiocytoma-like figures can appear in various poorly differentiated sarcomas.     

Chondroid chordoma: fine-needle aspiration cytology with histopathological, immunohistochemical, and ultrastructural study of two cases.

Chondroid chordoma is a controversial and confusing entity that was originally described by Heffelfinger et al. (Cancer 1973; 32:410-420) as a biphasic malignant neoplasm possessing elements of both chordoma and cartilaginous tissue. Fine-needle aspiration (FNA) cytology of chondroid chordoma has not been described. The aim of our investigation was to characterize the chondroid area of chondroid chordoma and to compare the FNA features with those of well-differentiated chondrosarcoma. Clival and cervical spine chondroid chordomas were studied with light microscopy, immunohistochemistry, and electron microscopy. Chondroid chordomas demonstrated an epithelial nature by immunohistochemistry and ultrastructural studies. The FNA smears showed low cellularity, with loosely arranged or dispersed round cells in a myxoid background. Although the smears were similar to those of well-differentiated chondrosarcomas, they showed a positive reaction for epithelial markers. These findings reveal that chondroid chordoma is a variant of chordoma which possesses a hyaline matrix. Immunohistochemical demonstration of epithelial markers is useful to distinguish it from chondrosarcoma. Diagn. Cytopathol. 1999; 21:335-339.     

Liposarcoma. A clinicopathologic subtyping of 52 cases

Fifty-two cases of liposarcoma were analyzed clinicopathologically, and were grouped into the following five types: myxoid (28 cases), well-differentiated (14 cases), pleomorphic (4 cases), round-cell (3 cases), and mixed (3 cases). Three of the 28 myxoid tumors showed a pleomorphic pattern resembling that of the myxoid variant of malignant fibrous histiocytoma, and one of the 3 round-cell tumors was considered to be a malignant counterpart of hibernoma. Ages ranged from 22 to 86 years with the average age of 49 years, the average patients with myxoid or round-cell liposarcoma being over 10 years younger than those with well-differentiated or pleomorphic liposarcoma. There was also a variation in the site of predilection of the cases: the great majority of myxoid type tumors occurred in the thigh, popliteal fossa and buttock (23 cases), while the majority of well-differentiated type tumors were seen in the retroperitoneum (10 cases). The rate of local recurrence of the tumor was 46%. Four of the 5 well-differentiated liposarcomas which recurred exhibited dedifferentiated pleomorphic components resembling those in malignant fibrous histiocytoma. The prognosis was more favorable in patients with ordinary myxoid tumors than in those with well-differentiated tumors. The overall relative five-year survival rate was 63%.     

LIPOSARCOMA

Fifty-two cases of liposarcoma were analyzed clinicopathologically, and were grouped into the following five types: myxoid (28 cases), well-differentiated (14 cases), pleomorphic (4 cases), round-cell (3 cases), and mixed (3 cases). Three of the 28 myxoid tumors showed a pleomorphic pattern resembling that of the myxoid variant of malignant fibrous histiocytoma, and one of the 3 round-cell tumors was considered to be a malignant counterpart of hibernoma. Ages ranged from 22 to 86 years with the average age of 49 years, the average patients with myxoid or round-cell liposarcoma being over 10 years younger than those with well-differentiated or pleomorphic liposarcoma. There was also a variation in the site of predilection of the cases: the great majority of myxoid type tumors occurred in the thigh, popliteal fossa and buttock (23 cases), while the majority of well-differentiated type tumors were seen in the retroperitoneum (10 cases). The rate of local recurrence of the tumor was 46%. Four of the 5 well-differentiated liposarcomas which recurred exhibited dedifferentiated pleomorphic components resembling those in malignant fibrous histiocytoma. The prognosis was more favorable in patients with ordinary myxoid tumors than in those with well-differentiated tumors. The overall relative five-year survival rate was 63%.     

Parachordoma of the tibia: report of a rare case

We report a case of recurrent parachordoma of the left anterior tibial region in a 64-year-old male patient. The tumor was a periosteal tender mass, and, histologically, displayed vague nodules of spindle to rounded eosinophilic cells embedded in a myxoid matrix. Large vacuolated (physalphorouslike) cells were noted as in sacrococcygeal chordoma. This tumor should be differentiated from myxoid chondrosarcoma, myxoid liposarcoma, chondromyxoid fibroma, and metastatic chordoma. The presence of physaliphorous cells in the tumor with positive immunoreactions caused by cytokeratin rules out the diagnosis of another myxoid tumor. The differential diagnosis from metastatic chordoma is basically made by clinicians. Even though parachordoma is usually regarded as a benign soft tissue neoplasm, two recurrences occurred in our case. Since the reported cases, including ours, have diverse clinical courses, it is essential to follow-up the patient carefully.     

Fine‐needle aspiration in myxofibrosarcoma: Experience of Institut Curie

Myxofibrosarcoma (MFS) is a well‐established nosologic entity different from the myxoid variant of malignant fibrous histiocytoma. In an attempt to better define the representative cytologic criteria of MFS, we undertook a review and a reanalysis of a series of 14 cytology samples in 12 patients whose tumors were diagnosed as MFS. Using FNA technique and reviewing the original diagnoses, 11 cases were diagnosed as malignant and three as benign tumors. The cytologic diagnosis of MFS was accurate in seven cases (2 primary tumors, 4 recurrences, and 1 metastasis). Four cases were classified malignant myxoid sarcoma (1 primary and 3 recurrences), whereas three cases (2 primary and 1 recurrence) were false‐negative. The smears were cell‐rich in 12 cases and cell‐poor in two cases. They were constantly composed of isolated and regular small spindle‐shaped and stellated cells with elongated nuclei containing small inconspicuous nucleoli. Cytoplasm was pale with elongated processes. Clusters of wavy spindle‐shaped cells, round cells without specific pattern, moderate cytonuclear atypia, and abundant myxoid background as well as curvilinear vascular structures were always seen. In the vast majority of cases, the cytologic distinction of MFS from other low‐grade myxoid lesions is difficult. Entities such as myxoid MFH, myxoid liposarcoma (MLP), myxoid DFSP, and myxoma should be considered in the differential diagnosis. The cytological misdiagnosis is of limited clinical consequence because FNA findings suggestive of a myxoid tumor will be indicative for a surgical removal followed by the histopathological analysis. Diagn. Cytopathol. 2010. © 2009 Wiley‐Liss, Inc.     

The Rise and Fall of Malignant Fibrous Histiocytoma

The term malignant fibrous histiocytoma was coined by Stout and associates in the 1960s to encompass pleomorphic soft tissue sarcomas presumably derived from histiocytes that are capable of fibroblastic transformation. The concept was reaffirmed in the following 2 decades and malignant fibrous histiocytoma thus was regarded as the most common soft tissue tumor in older adults. However, recent more critical clinicopathologic, ultrastructural, and immunohistochemical studies have shown that malignant fibrous histiocytomas are not derived from histiocytic “facultative fibroblasts” and many neoplasms so diagnosed actually are pleomorphic subtypes of other sarcomas. Meticulous electron microscopic and immunohistochemical investigations also found that the more common storiform–pleomorphic, myxoid, and perhaps the giant cell subtypes are composed of variable mixtures of fibroblasts and phenotypically modulated fibroblastic cells, notably myofibroblasts and histiofibroblasts. On the basis of these findings, we propose a new classification for the above subtypes of so-called malignant fibrous histiocytoma, the majority of which are variants of pleomorphic fibrosarcoma.     

The rise and fall of malignant fibrous histiocytoma

The term malignant fibrous histiocytoma was coined by Stout and associates in the 1960s to encompass pleomorphic soft tissue sarcomas presumably derived from histiocytes that are capable of fibroblastic transformation. The concept was reaffirmed in the following 2 decades and malignant fibrous histiocytoma thus was regarded as the most common soft tissue tumor in older adults. However, recent more critical clinicopathologic, ultrastructural, and immunohistochemical studies have shown that malignant fibrous histiocytomas are not derived from histiocytic "facultative fibroblasts" and many neoplasms so diagnosed actually are pleomorphic subtypes of other sarcomas. Meticulous electron microscopic and immunohistochemical investigations also found that the more common storiform-pleomorphic, myxoid, and perhaps the giant cell subtypes are composed of variable mixtures of fibroblasts and phenotypically modulated fibroblastic cells, notably myofibroblasts and histiofibroblasts. On the basis of these findings, we propose a new classification for the above subtypes of so-called malignant fibrous histiocytoma, the majority of which are variants of pleomorphic fibrosarcoma.     

Expression of E-cadherin in chordomas: diagnostic marker and possible role of tumor cell affinity

Chordoma is a relatively rare malignant bone tumor thought to arise from the remnants of the fetal notochord. Chordomas express epithelial cell markers such as cytokeratin and epithelial membrane antigen (EMA), which strongly suggests that the tumor cells grow via the mechanism of epithelial characterized cell-cell interactions. However, there are no known reports that have studied epithelial characterized cell-adhesion molecules such as E-cadherin or epithelial cell adhesion molecule (Ep-CAM) in chordomas. An immunohistochemical investigation was performed in seven cases of chordoma to determine the expression of pan-cytokeratin, Ep-CAM, and E-cadherin. Histological specimens showed the typical appearance of conventional chordoma but for two cases of chondroid chordoma. Cytokeratin was constantly expressed in conventional chordomas, but it was detected among a few cells with physaliphorous appearance in chondroid chordoma cases. Although no Ep-CAM expression was noted, E-cadherin was detected in most chordoma cells irrespective of histological subtypes. The expression of E-cadherin was negative among chondrosarcoma cells in this study as previously reported, and thus constant E-cadherin expression of chordoma cells suggests a role as a useful diagnostic marker to distinguish chondroid chordoma from chondrosarcoma. Furthermore, we speculate that E-cadherin may play a role in tumor cell adhesion and is also involved with histological and clinical features in chordomas.     

Fine-needle aspiration cytopathology of soft tissue: Chondromyxoid and myxoid lesions

Soft-tissue lesions pose an intimidating challenge to diagnostic interpretation by fine-needle aspiration cytology. to better characterize such aspirates, we investigated a subgroup of lesions which yielded a large amount of chondromyxoid and myxoid stroma (CMS). Thirty-three cases (22 malignant lesions, 11 benign lesions) in which CMS was a prominent feature of the smears were studied. the most common malignant neoplasms were extraskeletal chondrosarcoma (6 cases), myxoid liposarcoma (6), and malignant fibrous histiocytoma (5). the benign entities consisted of ganglion cyst (4), myxoma (3), and neurofibroma (2). of the aspirates from 22 malignant neoplasms, 15 (68%) contained opaque stroma, and in 18 (81%) the stroma was distributed as discrete clumps or fragments; all extraskeletal chondrosarcomas and chordomas contained these features. Additionally, in five of six chondrosarcomas the matrix exhibited cells within lacunae. Except for a tracheal chondroma which extended into the adjacent soft tissue, no benign aspirates had all three of these cytologic features. Twenty-three aspirates (70%) were moderately or highly cellular; all but two of these were malignant. Moderate to marked nuclear atypia occurred in 13/22 (59%) malignant and 1/11 (9.0%) benign aspirates. With a few exceptions, aspiration smears of benign lesions with abundant CMS were characterized by low cellularity, semitransparent amorphous stroma, and lack of nuclear irregularity. Recognition of variations in the character of the background material in addition to traditional cytologic criteria can aid in the diagnosis of benign and malignant chondromyxoid and myxoid aspirates of soft tissue. © 1995 Wiley- Liss, Inc.