Fine needle aspiration biopsy of myxoid metastasis of malignant melanoma

The cytopathologic features of the fine needle aspiration biopsy of a myxoid metastasis of a cutaneous malignant melanoma are documented. The cytologic findings included fusiform-to-round cells with elongated cytoplasmic processes, fibroblastlike cells and inflammatory cells in a characteristic amorphous background substance. Immunocytochemical staining for S-100 protein was positive. The cytologic findings correlated well the histologic, histochemical, immunohistochemical and ultrastructural studies of the neoplasm. The cytologic differential diagnosis between metastases of malignant melanoma and other myxoid tumors of soft tissues is discussed.     

Fine needle aspiration in myxoid tumors of the soft tissues

Myxoid tumors of soft tissues constitute a histogenetically heterogeneous group of lesions, both benign and malignant, that show an overproduction of mucopolysaccharide substances. A correlative fine needle aspiration (FNA) cytologic and histologic study was performed on 16 such cases (3 intramuscular myxomas, 2 lipoblastomas, 6 myxoid liposarcomas, 4 myxoid malignant fibrous histocytomas [MFHs] and 1 extraskeletal myxoid chondrosarcoma), with electron microscopic examination of the aspirate in 4 cases. FNA of all tumors produced a gelatinous material. Smears from all but one of the tumors had a granular myxoid background substance that stained blue to blue-red with the Diff-Quik stain; the exception was the extraskeletal myxoid chondrosarcoma, whose smears stained intensely blue-red to red. On light microscopy, only lipomatous tumors had distinctive cells with diagnostic value: the lipoblasts. Although the arrangement of lipoblasts in lipoblastomas differed somewhat from that found in myxoid liposarcomas, clinical data were important for making a definitive diagnosis. Intramuscular myxomas generally showed a low cellularity composed of fibroblastlike cells with no cytologic atypia. Myxoid MFHs were composed of fibroblastlike cells and macrophagelike cells; the elongated cells with slight-to-moderate nuclear atypia predominated in tumors of low-grade malignancy, while polygonal or round cells with one or more nuclei and marked nuclear atypia predominated in high-grade tumors. Although extraskeletal myxoid chondrosarcoma was mainly differentiated from low-grade myxoid MFH by its metachromatic matrix, ultrastructural studies showed the distinctive distended cisternae with microtubular aggregates in the extraskeletal myxoid chondrosarcoma, thus contributing to the definitive diagnosis.     

Low grade fibromyxoid sarcoma: report of a case with fine needle aspiration cytology and histologic correlation

BACKGROUND: Low grade fibromyxoid sarcoma has been fully described histologically; however, the fine needle aspiration (FNA) cytologic findings are scantily defined, and the distinction from other benign and malignant soft tissue tumors can be difficult. CASE: We examined FNA cytologic material from a slowly growing, large chest wall mass in a 28-year-old woman. The surgical specimen was processed for routine histology and immunohistochemical studies. The cytologic smears were adequately cellular, showing spindly cells with uniform, elongated nuclei; small, inconspicuous nucleoli; and scanty, wispy cytoplasm associated with myxoid material. No significant nuclear pleomorphism or mitoses were noted. The excised tumor was well circumscribed, focally infiltrating the surrounding muscles. The cut surface was variable, featuring fibrous, solid, fleshy and myxoid areas. Microscopically, the solid, fibrous areas displayed increased cellularity with storiform, intersecting and parallel patterns. In the myxoid areas the cells grew in a haphazard fashion and appeared floating in abundant mucoid matrix associated with a capillary vascular network similar to the chicken-wire pattern seen in cases of myxoid liposarcoma. The tumor cells were spindly, with fusiform, uniform nuclei. Focal, moderate nuclear pleomorphism was noted. The mitotic index was low. The tumor cells were positive for vimentin, alpha-1-antitrypsin and lysozyme and negative for S-100, actin, desmin and CD34. CONCLUSION: Although low grade fibromyxoid sarcoma is a rare neoplasm, it should be recognized and distinguished from other soft tissue tumors because of its low malignant potential. The definitive FNA cytologic diagnosis can be challenging but is possible if the tumor is adequately sampled, with multiple passes from different areas. Clinical and radiologic correlations are of great help. All spindle cell tumors with myxoid changes, such as myxoid liposarcoma, myxofibrosarcoma, cellular myxoma, myxoid leiomyosarcoma and peripheral nerve sheath tumors, should be considered in the differential diagnosis. In contrast to the cytologic features, the histologic findings are characteristic and well established.     

Cytomorphology of lipomatous tumors of soft tissue

OBJECTIVE: To evaluate the cytomorphologic features of benign and malignant lipomatous tumors of soft tissue on fine needle aspirates (FNA) and determine if the variants of liposarcoma could be identified. STUDY DESIGN: FNA of histologically documented benign (51 cases) and malignant (39 cases) lipomatous tumors were reviewed. Twenty-six of the 51 FNA from lipomas and 34 of the 39 FNA from malignant lipomatous tumors were satisfactory for evaluation. RESULTS: FNA from 26 cases of lipomas were cellular, with lobulated, fibroadipose tissue. Thin and thick capillaries were seen in 92% and 65% of cases, though a chicken wire vascular pattern was seen in only 4 cases (15%). A cytodiagnosis of liposarcoma could be made in 23 cases (88%), and these could be further subtyped into well-differentiated (4 cases), myxoid (8), pleomorphic (4), round cell (3) and liposarcoma, ?type (4). Only 50% of the well-differentiated liposarcomas, 3 of the 10 pleomorphic liposarcomas and 8 of the 17 myxoid liposarcomas were diagnosed as such on FNA. Cytologic diagnosis of the remaining 9 cases of myxoid liposarcoma were pleomorphic liposarcoma (1); liposarcoma, ?type (3); malignant mesenchymal tumor (1); suspicious for malignancy (2); and benign (2). There were no false positives, but there were 3 false negative cases (1 well-differentiated and 2 myxoid liposarcoma). CONCLUSION: Lipomas can be diagnosed readily. Arborizing vessels can be seen in lipomas and should be interpreted with caution. Subclassification of liposarcomas on FNA is possible but not very reliable. Myxoid liposarcomas pose a problem, and aspirates from them can mimic a wide range of morphologic subtypes. The role of FNA in identification of variants of liposarcoma is limited.     

Establishment and characterization of a human malignant fibrous histiocytoma line serially transplanted in nude mice

Serial heterotransplantation of human malignant fibrous histiocytoma (MFH) derived from tibia was attempted in BALB/c nu/nu mice, and HKMFH-nu transplantable tumor line was established. This line had the following biological properties. (1) Eighteen serial passages were carried out in 41 months. (2) Morphological changes of the grafts occurred in nude mice with serial passages: During the first 6 passages, histiological picture was consistent with the common type of MFH similar to that of the original tumor, then after the 7th passage, the myxoid type coexisted with the common type, and finally the myxoid type occupied the entire grafts to form large cysts. (3) The common type grafts grew more rapidly than the myxoid type grafts. (4) Granulocytosis (neutrophilia) was observed in mice bearing the common type tumor, but not in mice bearing the myxoid type tumor.     

Fine needle aspiration cytology of myxoid metastatic malignant melanoma

The macroscopic and microscopic findings in a fine needle aspirate of a myxoid metastatic malignant melanoma are presented. The macroscopically mucoid material and the microscopically normal appearance of the cells in the myxomatous background were pitfalls while the presence of a melanin-positive pigment was a clue to the correct diagnosis.     

Extraskeletal myxoid chondrosarcoma of the chest wall masquerading as a breast tumor. A case report

BACKGROUND: Extraskeletal myxoid chondrosarcoma is a rare tumor that usually occurs in the soft tissues of extremities. Cytologic features of chondrosarcoma arising from a rib and presenting as a breast mass were reported by Molyneux et al in 1995. However, to the best of our knowledge, the cytology of extraskeletal myxoid chondrosarcoma of the chest wall presenting as a breast mass has not been documented before. CASE: A 30-year-old female presented with left-sided chest pain and a hard lump in the breast of two months' duration. Fine needle aspiration cytology was done, and a possible diagnosis of mucinous carcinoma or mixed tumor of the breast was suggested, with advice to prepare a frozen section before undertaking a radical procedure. On imprint cytology and frozen section a diagnosis of extraskeletal myxoid chondrosarcoma was made and confirmed by histopathology and immunohistochemistry. CONCLUSION: It is rare for extraskeletal myxoid chondrosarcoma to occur in the chest wall. This problem is compounded by the fact that cells of extraskeletal myxoid chondrosarcoma which resemble epithelial cells, can very closely mimic some malignant breast tumors.     

Acral myxoinflammatory fibroblastic sarcoma in FNAB samples: can we distinguish it from other myxoid lesions?

We analysed cytomorphological characteristics of three fine needle aspiration biopsy (FNAB) samples of acral myxoinflammatory fibroblastic sarcoma (AMIFS) as well as the features of a number of other benign and malignant myxoid lesions. The analysis showed that FNAB samples from two cases of AMIFS had similar cytomorphology, containing all the characteristic features described in surgical biopsies: myxoid material, spindle cells with bipolar cytoplasmic extensions, epithelioid cells with globules of extra-cellular material, ganglion-like and lipoblast-like giant cells. Only the inflammatory component was scarce. The third sample did not contain features typical of AMIFS. Samples from other myxoid tumours resembled AMIFS to some extent, however, none of them contained all three tumour components characteristic of AMIFS. Cytomorphology of AMIFS may be characteristic enough to enable a definitive diagnosis from FNAB, provided all the distinctive features are sampled.     

Retroperitoneal mesenchymal chondrosarcoma. Report of a case diagnosed by fine needle aspiration cytology

An unusual case of retroperitoneal mesenchymal chondrosarcoma diagnosed by fine needle aspiration (FNA) biopsy is described. CT-guided FNA of a mass arising in retroperitoneal soft tissues yielded an amorphous, myxoid material containing two distinct and separate populations of tumor cells. One was an undifferentiated, monomorphic, small cell component with granular cytoplasm and round central nuclei. The second population was an overtly malignant chondroid component scattered within an abundant myxoid matrix showing foamy cytoplasm, marked nuclear pleomorphism and frequent multi-nucleation. These cytologic findings were distinctive and similar to the histologic findings. The differential diagnosis and the possible pitfalls in the FNA diagnosis of this relatively rare tumor are discussed.     

Cytologic features of a primary myxoid malignant fibrous histiocytoma arising in the uterus: a case report.

BACKGROUND: Primary malignant fibrous histiocytoma (MFH) of the uterus is extremely rare. The 10 cases reported in the literature all involved the pleomorphic variant, and to the best of our knowledge, the myxoid variant has not been reported before. We describe the cytologic findings of primary uterine myxoid MFH in relation to the myxoid component, potentially leading to an incorrect diagnosis. CASE: A 68-year-old woman presented with a primary uterine tumor. Endometrial cytology showed numerous loosely arranged, spindle-shaped fibroblastlike cells; atypical histiocytelike cells; and giant cells with a necrotic background. The overall cytologic picture was of a degenerated pleomorphic leiomyosarcoma with an inconclusive diagnosis. A diagnosis of myxoid MFH was established after electron microscopic and immunohistochemical studies of the primary tumor and tumor transplanted, as primary cultured cells, in nude mice. The patient underwent an exploratory laparotomy and died of tumor progression 38 days after the initial consultation, without treatment. CONCLUSION: Because of overlapping cytologic features among uterine sarcomas with myxoid stroma, it is important to recognize the histiocytic lineage of tumor cells by immunohistochemistry and electron microscopy in various presentations of fresh samples.     

In vitro differentiation of myxoid liposarcomas maintained in organ culture system.

Liposarcoma falls into the differential diagnosis of myxoid malignant mesenchymal tumors. On the other hand, its relation with white or brown fat is controversial. Two cases of liposarcoma have been studied by organ culture, a method which provides cell and tissue redifferentiation in vitro. Both cases developed successively cytoplasmic glycogen granules and lipid droplets as well as a single lipidic vacuole in the late phase of cultivation as a marker of fat differentiation. Our results support the possibility of identifying myxoid liposarcomas as well as their origin from white fat tissue.     

Cytopathologic aspects of pulmonary metastasis of malignant fibrous histiocytoma, myxoid variant: fine needle aspiration biopsy of a case

The cytopathologic findings of a fine needle aspiration biopsy of pulmonary metastasis of a malignant fibrous histiocytoma, myxoid variant, are documented. Isolated and irregular loose clusters or bundles of spindle cells and pleomorphic multinucleated giant cells were found. No signet-ring lipoblastlike cells were identified. The cytologic findings were similar to the histology of the primary tumor removed from the patient's leg 18 months previously.     

Fine needle aspiration biopsy of myxoid variant of malignant leiomyoblastoma metastatic to the liver

The cytologic features seen in a fine needle aspiration biopsy specimen of a liver metastasis from a myxoid variant of a malignant leiomyoblastoma (epithelioid leiomyosarcoma) of the stomach are presented. The abundant mucus production and rich vascularity evident in the aspiration smears corresponded to the histologic findings in the original tumor, which had been excised two years previously. Histochemical and immunochemical staining were used to substantiate the smooth-muscle origin of the tumor.     

Comparison of immunohistochemical labelling of melanocyte differentiation antibodies melan-A, tyrosinase and HMB 45 with NKIC3 and S100 protein in the evaluation of benign naevi and malignant melanoma

A panel of three melanocyte differentiation antibodies has been compared with anti-S100 protein and NKIC3 in an assessment of benign and malignant melanocytic lesions.Anti-polyclonal S100 protein labelled all cases of primary cutaneous malignant melanoma, metastatic melanoma, desmoplastic melanoma and myxoid melanomas. In addition all benign and dysplastic naevi were positive. Conversely, HMB 45 was the least sensitive marker, labelling 24/31 primary cutaneous melanomas, 14/24 metastatic melanomas and only 1/6 desmoplastic melanomas. In the case of naevi, only junctional forms labelled consistently. Results for anti-melan-A and anti-tyrosinase were similar, although anti-tyrosinase proved slightly more sensitive in cases of malignant melanoma. NKIC3 revealed similar results to anti-tyrosinase, but had the disadvantage of reduced selectivity.It is concluded that anti-tyrosinase and anti-melan-A are useful additions to the panel of melanocytic monoclonal antibodies. In addition, both antibodies appear to have greater sensitivity for malignant melanoma than the conventionally used HMB 45 and could be considered as supportive markers to polyclonal anti-S100 protein in the diagnosis of malignant melanoma.     

Logistic regression analysis of high grade spindle cell neoplasms. A fine needle aspiration cytologic study.

OBJECTIVE: To identify primary diagnostic cytologic criteria for various high grade spindle cell neoplasms. STUDY DESIGN: We reviewed 30 osteosarcomas, 29 malignant fibrous histiocytomas (MFH), 26 malignant melanomas, 13 chondrosarcomas, 12 leiomyosarcomas, 7 angiosarcomas and 5 liposarcomas. All specimens were coded as to the presence or absence of the following variables: high or low cellularity, tissuelike fragments, glandlike fragments, single cells, binucleated cells, multinucleated cells, lipoblastlike cells, histiocytelike cells, fibroblastlike cells, signet-ring cells, short spindle cells, long filamentous cells, stellate cells, osteoclastic giant cells, malignant giant cells, background cells, pointed nuclei, cigar-shaped nuclei, fishhook-shaped nuclei, round or ovoid nuclei, intranuclear vacuoles, macronucleoli, small nucleoli, mitotic figures, abnormal mitotic figures, pleomorphism, nuclear/cytoplasmic ratio (mild, moderate, marked increase), amount of cytoplasm (scant, moderate, abundant), fine or coarse granular cytoplasm, intracytoplasmic hemosiderin deposits, melanin, cytoplasmic vacuoles, fat, capillary vessel fragments, storiform pattern, necrosis, large or small amount of myxoid material, filamentous stroma, dense collagenous stroma, osteoid, chondroid and cells in lacunae. A logistic regression analysis was performed to identify the variables predictive of each diagnostic category. RESULTS: The statistical analysis selected positive expression of osteoid, osteoclastic giant cells and low cellularity as the primary criteria associated with osteosarcomas. Positive expression of fibroblastlike cells, large amount of myxoid material and multinucleated cells were identified to be the key criteria for MFH. The analysis selected the presence of melanin as the major criterion for malignant melanomas, cells lying in lacunae for chondrosarcomas, fishhook nuclei for leiomyosarcomas, intracytoplasmic iron deposits for angiosarcomas and lipoblastlike cells for liposarcomas. CONCLUSION: From the previously described cytologic criteria, statistical analysis helped identify several key features that are significant in the evaluation of pleomorphic spindle cell neoplasms.     

Logistic regression analysis of low grade spindle cell lesions. A cytologic study

OBJECTIVE: To identify key diagnostic cytologic criteria for various low grade spindle cell lesions. STUDY DESIGN: We reviewed 20 synovial sarcomas, 18 benign neural tumors, 10 reparative lesions, 24 other benign and 27 additional malignant low grade spindle cell lesions. All specimens were coded as to the presence or absence of the following variables: high cellularity, tissue fragments, tissue culture appearance, epithelial fragments, vessel fragments, vascular arcades, fibrillar ground substance, myxoid background, microcystic areas, parallel arrangement of nuclei, naked nuclei, single cells, binucleate cells, multinucleate cells, long filamentous cells, short spindle cells, stellate cells, lipoblasts, nuclear pleomorphism, nuclei with pointed ends, comma/fishhook nuclei, cigar-shaped nuclei, ovoid/round nuclei, small nucleoli, large nucleoli, mitotic figures, intranuclear vacuoles and background histiocytes. A logistic regression analysis was performed to identify the variables predictive of malignant lesions, specifically synovial sarcomas, benign neural tumors and reparative lesions. RESULTS: Statistical analysis selected high cellularity, short spindle cells, small nucleoli and absence of tissue culture appearance as the main criteria for malignant neoplasms. Tissue fragments and high cellularity were selected as the primary criteria and absence of long filamentous cells and of myxoid background as the secondary criteria for synovial sarcomas. It selected fibrillar ground substance and absence of ovoid/round nuclei as the key criteria for benign neural tumors. The presence of a tissue culture appearance was the major criterion for reparative lesions. CONCLUSION: There are many previously described cytologic criteria, but we found that when subjected to statistical analysis, only a few features were significant in the evaluation of low grade spindle cell lesions.     

Chromosome localization of the human oncogene INT1 to 12q13 by in situ hybridization

The human oncogene INT1 has been mapped to chromosome band 12q13 by in situ hybridization. The precise localization of this gene is of particular interest, since the region 12q13----q14 has been reported to be involved in chromosomal rearrangements in lipomas, myxoid liposarcomas, pleomorphic adenomas, and myomas. The involvement of this region in both benign and malignant tumors suggests a common pathogenetic pathway in which changes affecting INT1 may be an important step.     

Immunohistochemical evaluation of versican,in relation to chondroitin sulphate,in canine mammary tumours

The expression of increased amounts of versican, a chondroitin sulphate proteoglycan, in neoplastic tissues may play a role in promoting tumour cell proliferation and migration. This study investigated the immunolocalization of versican in normal and neoplastic canine mammary tissues, using antibodies 12C5 and 2B1, against different epitopes of the protein core of versican. Antibody CS56, recognising chondroitin sulphate (CS), was used to investigate the relation between versican and CS, which accumulates in canine mammary tumours. We found enhanced versican expression in both benign and malignant tumours, appearing in three main patterns: in periductal tissues, probably in association with basement membranes of ducts; in peripheral invasive areas of malignant tumours; and in spindle cell proliferations and myxoid areas of complex and mixed tumours. The 12C5 and 2B1 immunoreactivities co-localised in all types of tumours, and could be improved by chondroitinase digestion. The only exception was the abundant extracellular matrix (ECM) of spindle cell proliferations, particularly in myxoid areas of complex and mixed tumours, which displayed intense and diffuse 12C5 immunoreactivity and patchy or absent 2B1 and CS56 immunoreactivities; versican immunoreactivity could not be enhanced by chondroitinase digestion. The results indicate that versican is one of the extracellular matrix components characteristic of canine mammary tumours. It appears likely that in complex and mixed tumours versican exists in at least two forms, one of them lacking the CS attachment domain and the 2B1 epitope. Furthermore, the enhanced versican expression in the invasive areas of malignant tumours indicates the involvement of this proteoglycan in tumour cell invasion.     

Morphopathology of mixed sweat-gland tumors

Mixed sweat-gland tumors were studied on 11 biopsies, of which two showed clear-cut morphological features of malignancy. Stress was laid upon the sudoriferous-duct histogenesis of such tumors. Several peculiarities were carefully investigated, especially epithelial proliferation in sheets, cords, tubes, isolated cells and certain epithelial metaplasias correlated with various mesenchymal stroma changes, such as fibrosis, myxoid, chondroid or even osseous changes. Special emphasis was also laid upon the comparative aspects between benign and malignant mixed sweat-gland tumors and other similar body tumors.     

Myxoid leiomyosarcoma of the uterus. Report of a case with cytologic findings

BACKGROUND: Myxoid leiomyosarcoma is a rare variant of uterine sarcoma, exhibiting malignant biologic behavior despite the absence of cytologic atypia and of significant mitotic activity. CASE: A 20-year-old female was referred with a cystic pelvic mass. At laparotomy, the tumor, weighed 2,200 g and originating in the left lateral uterine wall, was removed. Microscopic examination revealed well-differentiated smooth muscle cells without atypia and with a few mitotic figures in the copious myxoid matrix, suggesting myxoid leiomyosarcoma. Three years following laparotomy, an irregular mass around the uterus was noted on sonographic examination, suggesting local recurrence. Two years and six months later, the second operation was performed, and a locally recurrent, multicystic tumor weighing 3,500 g was excised. The histopathology was similar to that of the primary tumor. Cytologic findings on imprint material from the tumor revealed a few isolated or sheet like small cells consisting of spindle and polygonal cells with round and oval nuclei. Cytologic atypia was also minimal. CONCLUSION: Myxoid leiomyosarcoma should be included in the differential diagnosis of smooth muscle neoplasia.