Chromosome abnormalities in liposarcomas

Intradermal Proliferative Fasciitis Occurring With Chondrodermatitis Nodularis Helicis

Nodular fasciitis is a benign myofibroblastic tumor. Its uncommon variant, proliferative fasciitis (PF), can present in an even less common intradermal form. We report a case of intradermal PF of the ear in a 45-year-old man who presented with recurrent episodes of pain and swelling of the lesion. Histologic examination showed a dermal, nodular proliferation of ganglion-like basophilic fibroblasts with prominent nuclei and nucleoli, admixed with foamy histiocytes and areas of spindle cells arranged in intersecting fascicles in a fibromyxoid background. Lesional cells stained positive for smooth muscle actin and were negative for AE1/AE3, p63, and Melan-A. CD68 highlighted intervening histiocytes. We postulate that the underlying chondrodermatitis nodularis helicis was a triggering etiology, consistent with the current speculation that intradermal PF results from trauma.

Molecular cytogenetic characterization of two established ESFT cell lines

Ewing's sarcoma/primitive neuroectodermal tumor/Askin's tumor (Ewing`s sarcoma family of tumors: ESFT) is the most common type of malignant tumor of bone and soft tissue in children and young adults, and morphologically is a member of a group of small round cell tumors. We report, here, on the establishment of two human ESFT cell lines, FU-PNET-3 and FU-PNET-4, from the iliac and the chest wall, respectively, the cells of both cell lines were tumorigenic in immunodeficient mice. Histologically, both original and xenograft tumors and cultured cells were composed of small round cells with positive immunoreactivity for CD99 and Nkx2.2. Molecular biological examination demonstrated chimeric transcripts of EWSR1 exon 7 to FLI1 exon 6 in FU-PNET-3 cells, and EWSR1 exon 10 to FLI1 exon 6 in FU-PNET-4 cells. Cytogenetic analysis revealed chromosome translocation t(11;22)(q24;q12) and some secondary changes in both cultured cells. These histological, molecular biological, and cytogenetical findings indicate ESFT in both cell lines. ESFT is well studied, but its recurrent fusion genes are heterogeneous and its biological behaviors are unclear. The FU-PNET-3 and FU-PNET-4 cell lines have been well examined and may become useful tools for studying the genetic and biological behavioral properties of ESFT.

Extensive lipoma-like changes of myxoid liposarcoma: morphologic, immunohistochemical, and molecular cytogenetic analyses

Myxoid liposarcomas (MLSs) with extensive lipoma-like changes (MLSLC) are rare, and it is often difficult to distinguish them from well-differentiated liposarcoma (LS)/dedifferentiated LS (WDLS/DDLS) with myxoid changes. For the characterization of these neoplasms, we studied 8 MLSLCs, 11 ordinary MLSs, 4 WDLSs, and 6 DDLSs. Cytogenetically, MLSLC and ordinary MLS were characterized by t(12;16)(q13;p11) and FUS-DDIT3 fusion gene, whereas WDLS/DDLS lacked the fusion gene but possessed giant marker/ring chromosomes. Both lipoma-like and myxoid components of the same MLSLC exhibited the identical FUS-DDIT3, as confirmed by fluorescence in situ hybridization (FISH) and reverse transcription polymerase chain reaction (RT-PCR). Immunohistochemically, MDM2 and CDK4 were positive in WDLS/DDLS but negative in MLSLC and ordinary MLS. PPARγ, C/EBPα, adipophilin, and perilipin were found in each type of LS. Adipophilin was expressed chiefly in tiny fat droplets of immature lipoblasts, whereas perilipin showed a strong positive staining in large fat vacuoles of signet ring and multivacuolated lipoblasts. The Ki-67 labeling index was lower in the lipoma-like component of MLSLC when compared with the myxoid component of the same tumors as well as ordinary MLS (p < 0.001). When compared with ordinary MLS, MLSLC may be less aggressive in clinical behavior (rare recurrences or metastases) after a wide surgical excision. In conclusion, the distinction between MLSLC and WDLS/DDLS is important, because of the differences of molecular cytogenetic features as well as clinical behaviors between these distinct sarcomas presenting similar morphologic features. In addition, the combined immunohistochemical detection of adipophilin and perilipin may provide a useful ancillary tool for identification of lipoblastic cells in soft tissue sarcomas.

Ossifying fibromyxoid tumor of soft parts. Cytogenetic findings

Ossifying fibromyxoid tumor (OFMT) of soft parts is a recently described, rare but morphologically distinctive soft tissue tumor. The histogenesis of this lesion remains uncertain, although several immunohistochemical and ultrastructural features suggest that it is an unusual neural tumor, possibly of Schwann cell origin. We report here a case of a malignant variant of OFMT that occurred in the foot of a 52-year-old man. The karyotype of a pulmonary metastasis exhibited the following complex numeric and structural aberrations:72 approximately 74,XXY,-5,+6,+del(8)(p21),del(9)(p22),+10,der(11)t(3;11)(p21;p15),del(12) (q13),der(13)t(5;13)(q13;q34),+18,+19,+20,-22 [cp10]. A kidney metastasis exhibited the following karyotypic abnormalities: 46,XY,add(3)(p11),+der(3)t(3;?;11)(3qter-->3p11::?::11q13-->11qter), -5,del(8)(p21),add(9)(q22),del(9)(p22),der(11)t(3;11)(p21;p15),del(12)(q13),+der(13)t(5;13) (q13;q34),-22. To our knowledge, this is the first reported case of OFMT in which clonal chromosomal aberrations have been shown.

Supernumerary ring chromosomes in dermatofibrosarcoma protuberans may contain sequences from 8q11.2-qter and 17q21-qter: a combined cytogenetic and comparative genomic hybridization study

Dermatofibrosarcoma protuberans (DFSP) presents with characteristic cytogenetic features such as reciprocal t(17;22)(q22;q13) or, more commonly, supernumerary ring chromosomes containing sequences from chromosomes 17 and 22. Here, we report the identification of a novel abnormality in a 43-year-old woman with DFSP. Cytogenetic analysis of tumor cells showed the presence of a supernumerary ring chromosome as the sole anomaly. Amplification of 8q11.2 approximately qter and 17q21 approximately qter sequences was confirmed by comparative genomic hybridization (CGH); the present case apparently lacked amplification of chromosome 22. To our knowledge, this is the first case indicating that the ring chromosome in DFSP is possibly associated with amplified material from chromosomes 8 and 17.

Translocation (12;17)(q13;q23) in de novo acute myeloid leukemia with trilineage myelodysplasia

12q13 abnormalities have been reported to be associated with a variety of benign and malignant solid tumors. Recently, they have been shown to be a nonrandom karyotypic change in acute myeloid leukemia. We report a case of de novo acute myeloid leukemia with trilineage myelodysplasia showing t(12;17)(q13;q23) as the sole chromosomal abnormality. A review of the literature indicates that 12q13 translocation in acute myeloid leukemia is often associated with concomitant dysmyelopoietic changes. There is also evidence to suggest that 12q13 translocation occurs more frequently in acute myeloid leukemia with a prior history of mutagenic exposure or karyotypic indicators of secondary leukemia.

Translocation (3;16)(q27;p11) in a patient with diffuse large B-cell lymphoma associated with the BCL-6 gene rearrangement

A patient with B-cell lineage diffuse large-cell lymphoma carrying the t(3;16)(q27;p11) and BCL-6 rearrangement is described. Cytogenetic studies showed 46,XY,t(3;16)(q27;p11.2)[.11]/46,idem,add(18)(q21)[7]/46,XY[2]. The chromosomal translocation involving the 3q27 locus was associated with the BCL-6 gene rearrangement identified by Southern blot analysis. This case involved systemic lymph nodes, as large as 3 cm in diameter, bilaterally in neck, axilla, and inguinal regions. The patient obtained complete remission with chemotherapy.

Renal primitive neuroectodermal tumor: a morphologic, cytogenetic, and molecular analysis with the establishment of two cultured cell lines

We report two patients with renal primitive neuroectodermal tumor (PNET) in whom the diagnosis was established by both a cytogenetic and a molecular analysis. Histologically, both renal tumors were composed of uniform immature round cells with a positive immunoreactivity for O13 (p30/32 MIC2). The cytogenetic analysis with in situ hybridization (chromosome painting) demonstrated reciprocal translocation t(11;22)(q24;q12) specific to PNET in the cultured cells derived from each tumor. The reverse transcriptase-polymerase chain reaction (RT-PCR) in both tumors demonstrated EWS/ FLI-1 fusion transcripts, representing the molecular equivalent of t(11;22). A Southern blot analysis also confirmed EWS gene rearrangement in both renal tumors. In addition, the authors also established two new cell lines (designated as FU-RPNT-1 and FU-RPNT-2) from renal PNETs. When transplanted into athymic mice, FU-RPNT-1 and FU-RPNT-2 reproduced and maintained the morphologic and molecular characteristics of the original tumors. In conclusion, the detection of t(11;22) and EWS/FLI-1 fusion transcripts is considered to provide a novel adjunctive method for diagnosing renal PNET. These newly established cell lines thus may be used to investigate the biologic behavior related to renal PNETs.

Cytogenetic analysis of a case of myxoid liposarcoma with cartilaginous differentiation

The cytogenetic analysis of a patient with a myxoid liposarcoma exhibiting cartilaginous differentiation is presented. A complex translocation involving chromosome 12, 16, and 19 was found, instead of the t(12;16), specific for myxoid liposarcoma. The involvement of 19q13 in a tumor with cartilaginous differentiation, and the assignment of TGF beta 1 to 19q13.1-13.2, which appears to play a role in the formation of bone and cartilage, suggest a possible relation between both.

Epithelioid sarcoma with an 18q aberration

Epithelioid sarcoma is a peculiar soft-tissue neoplasm of uncertain origin, which is characterized by an epithelioid morphology of tumor cells coexpressing epithelial (keratin) and nonepithelial (vimentin) antigens. We herein report a new cytogenetic abnormality with der(22)t(18;22)(q11;p11.2) in a case of epithelioid sarcoma that occurred in the elbow of a 75-year-old man. Histologically, the tumor demonstrated a multinodular proliferation of epithelioid cells, with positive immunostaining for keratin, epithelial membrane antigen (EMA), and vimentin. Cultured tumor cells obtained from fresh surgical materials were frozen in plastic ampules and stocked in a liquid nitrogen freezer. Six years after surgery, the cells were recovered from the freezer and utilized for both morphologic and cytogenetic analyses. These cultured cells both before and after the freezing exhibited essentially the same epithelioid morphology and immunophenotypes as those of the original tumor. A chromosome analysis, together with fluorescence in situ hybridization (FISH), demonstrated a 61-67 modal population, and a characteristic clonal abnormality with der(22)t(18;22)(q11;p11.2). Other clonal abnormalities included numerical (-3, -4, +7, -13, -14, -16, -18, +20, -22) and structural (8p+, 9p+, 12p+, i(21q)) aberrations. Some variant clones also demonstrated i(18q). Since the breakpoint at 18q11 is similar to that reported in synovial sarcoma, this finding may support the presence of a histogenetic relationship between epithelioid sarcoma and synovial sarcoma. Our study thus indicates that the storage of frozen cells is useful for both morphologic and cytogenetic analyses of soft tissue tumors.

The clinicopathologic spectrum of myxoid and round cell liposarcoma. A study of 95 cases

BACKGROUND

The prognosis of patients with myxoid liposarcoma (ML) or round cell liposarcoma (RCL) has never been adequately defined.

METHODS

We evaluated the clinical and pathologic features of 95 patients with biopsy proven ML or RCL examined at the Mayo Clinic between 1971 and 1992. Routine hematoxylin and eosin stained slides of all cases were reviewed. Morphologic variable evaluated included percent of round cell differentiation, percent of lipoblastic differentiation, and presence of tumor necrosis. Clinical follow-up was available for 86 patients (range: 6 months-23.4 years; mean: 7.2 years; median: 5.9 years). Flow cytometry for determination of DNA ploidy was performed on paraffin embedded tissue available from 46 cases. Survival analyses for the 86 patients with adequate clinical follow-up were performed by the Kaplan-Meier test using the approximate chi-square statistic for the log rank test.

RESULTS

Age at diagnosis ranged from 16 to 81 years (median: 44 years). The extremities were involved in 91 cases, the retroperitoneum in 3 cases, and the perineum in 1 case. The single most common location was the thigh (61 cases). Histologically, round cell differentiation was present in 41 cases (43%) ranging from 5% to 100% of the tumor volume. Only one case of "pure" RCL was used in the study. Spontaneous tumor necrosis was noted in 4 cases. By flow cytometry, 38 tumors were diploid, 6 were aneuploid, and 1 was tetraploid. The data from 1 case was uninterpretable. Thirty patients (35%) developed metastasis; 27 (31%) died from the disease.

CONCLUSIONS

With multivariate analysis, age ( > 45 years), percent of round cell differentiation ( > or = 25%), and the presence of spontaneous tumor necrosis are significantly associated with a poor prognosis. No correlation was observed between DNA ploidy (i.e., diploid vs. aneuploid) and percent of round cell differentiation or clinical outcome.

Renal primitive neuroectodermal tumor: an immunohistochemical and cytogenetic analysis

The cytogenetic and morphologic characteristics of a case with a primitive neuroectodermal tumor (PNET) arising from the left kidney in a 22 year old man are presented. The patient was detected as having a left renal mass with a tumor embolus in the inferior vena cava and multiple pulmonary metastases. A radical nephrectomy with tumor embolectomy of the inferior vena cava, along with a resection of the pulmonary nodules were performed. Histologic examination revealed a dense proliferation of small round cells with many Homer-Wright type rosettes and perivascular pseudorosettes. Immunohistochemically, the tumor cells stained strongly positive for HBA71(p30/32MIC2), a surface glycoprotein specific to PNET and Ewing's sarcoma. In addition, the tumor cells expressed several neural markers (neuron specific enolase, neurofilament, synaptophysin, and Leu-7) and vimentin, while the epithelial, muscular, and lymphocytic markers were negative in the tumor cells. Cytogenetic analysis of cultured tumor cells showed a reciprocal translocation t(11;22)(q24;q12) that is considered to be specific to PNET and Ewing's sarcoma. In conclusion, this case suggested that a karyotyping analysis is a useful diagnostic tool for renal PNET, and it may therefore be utilized to help distinguish between difficult cases of small round cell tumors and Wilms' tumor of the kidney.

Gains and losses of DNA sequences in liposarcomas evaluated by comparative genomic hybridization

Comparative genomic hybridization (CGH) was used to detect and map the regions of gain, high-level amplification, and loss of DNA sequences in 14 liposarcomas. Thirteen tumors showed DNA sequence copy number changes of one or more genomic regions (mean, six aberrations/tumor; range, 0-17). These aberrations were observed in almost every chromosome but some chromosomal regions were affected more often than others. DNA sequence gains were more frequent than losses. The most common gain was seen at 12q14-21 (50% of tumors). Other frequent gains (29%) were of 1q21-24, 8cen-q21.2, 19q, and 20q. High-level amplification was observed in six (43%) tumors and included as minimal common segments bands 12q15, 1q22, and 1q24. In five (36%) tumors, sequences at 1q21-24 and 1q32 were found to be gained simultaneously with 12q14-21, which means that in 71% of the tumors with gain at 12q, an increase of DNA sequence copy number at 1q was also observed. The most common losses of DNA sequences (21%) occurred from regions 9p21-pter and 13q21-qter. Most of the aforementioned regions have not previously been reported to be altered in liposarcomas. The detection of a novel recurring amplicon at 1q21-24 with high-level amplification at 1q22 and frequent simultaneous DNA sequence gain at 12q14-21 (high-level amplification at 12q15) suggests that genes linked to both these regions may play a significant role in the development and progression of liposarcomas.

Trisomy 8 in alveolar soft part sarcoma

Cytogenetic studies were performed on an alveolar soft part sarcoma of a 6-year-old boy. An extra chromosome 8 was present in 26 of 28 metaphases analyzed.

Deletion 6q in three cases of mixed-type liposarcoma in addition to t(12;16)(q13;p11)

We report the cytogenetic findings in three mixed liposarcoma following short-term cultures. During the course of cytogenetic investigation of various types of liposarcomas, we observed an interstitial deletion of the long arm of chromosome 6 together with the translocation (12;16)(q13;p11) in three tumors. Translocation (12;16) is associated with myxoid and mixed (myxoid/round cell) liposarcomas, although deletion of chromosome 6 has been observed in only a few of these tumors. Our findings suggest that del(6), as an additional change in myxoid liposarcoma, is probably related to tumor progression.

Cytogenetics of tumors of soft tissue and bone. Implication for pathology

Pathologists should be aware of the existence of diagnostically useful chromosomal rearrangements in several soft tissue and bone tumors. They include rearrangement of 8q12 in lipoblastomas, ring chromosomes in atypical lipomas, ring and giant marker chromosomes in well differentiated liposarcomas, t(12;16)(q13;p11) in myxoid liposarcomas, rearrangement of 7p21-22 in low-grade endometrial stromal sarcomas, t(2;13)(q37;q14) in alveolar rhabdomyosarcomas, t(X;18)(p11.2;q11.2) in synovial sarcomas, t(12;22) (q13;q13) in clear cell sarcomas, t(11;22)(q24;q12) in Ewing's sarcomas and peripheral neuroepitheliomas, and t(9;22)(q21-31;q11-12) in extraskeletal myxoid chondrosarcomas.

Myxoid liposarcoma. Experience with chemotherapy

BACKGROUND

Myxoid liposarcoma (ML) is the most common type of liposarcoma. It has been classified as an intermediate grade tumor with a definite metastatic potential but a relatively indolent natural history. Little is known about its sensitivity to chemotherapy.

METHOD

The authors reviewed their experience with chemotherapy in ML from 1986 to 1992. The patient population was identified through a search of the database maintained by the Department of Melanoma-Sarcoma Medical Oncology of the M.D. Anderson Cancer Center.

RESULTS

Forty-four patients each with a histologically confirmed diagnosis of ML were identified. Twenty-one were treated with chemotherapy. The median age was 45 years (31-69 years); there were 14 men and 7 women. The ML in 19 patients was in the lower extremity, one in the head and neck, and one pelvic. The median size of the primary tumor was 15 cm (range, 7-48 cm) in maximum dimension. Of the 18 patients who received doxorubicin- and dacarbazine-based chemotherapy as a frontline regimen [median of 3 (2-9) cycles] and were evaluable for response, 8 (1 completed response, 7 partial responses) achieved an objective response (44%, 95% confidence interval 21-67%). Two of the remaining three patients who were also treated with a similar regimen were not evaluable for response (one received chemotherapy postoperatively, and the other received concomitant radiation and doxorubicin), and the third patient received ifosfamide as frontline chemotherapy because of a significant cardiac history. Seven patients received chemotherapy in the neoadjuvant setting, 13 for recurrent or metastatic disease, and 1 postoperatively after complete tumor resection. At the last follow-up, 10 patients were alive with no evidence of disease, 3 were alive with disease, and 8 had died. The median follow-up was 51 months (range, 6-199 months) from diagnosis.

CONCLUSION

The authors conclude that doxorubicin- and dacarbazine-based chemotherapy is effective in the treatment of ML.