Alveolar soft part sarcoma. An immunohistochemical, cytologic and electron-microscopic study and a quantitative DNA analysis

The Extracellular Matrix in Soft Tissue Sarcomas: Pathobiology and Cellular Signalling

Soft tissue sarcomas are rare cancers of mesenchymal origin or differentiation comprising over 70 different histological subtypes. Due to their mesenchymal differentiation, sarcomas are thought to produce and deposit large quantities of extracellular matrix (ECM) components. Interactions between ECM ligands and their corresponding adhesion receptors such as the integrins and the discoidin domain receptors play key roles in driving many fundamental oncogenic processes including uncontrolled proliferation, cellular invasion and altered metabolism. In this review, we focus on emerging studies that describe the key ECM components commonly found in soft tissue sarcomas and discuss preclinical and clinical evidence outlining the important role that these proteins and their cognate adhesion receptors play in sarcomagenesis. We conclude by providing a perspective on the need for more comprehensive in-depth analyses of both the ECM and adhesion receptor biology in multiple histological subtypes in order to identify new drug targets and prognostic biomarkers for this group of rare diseases of unmet need.

Surgical management and outcome of spinal alveolar soft part sarcoma (ASPA): a case series of five patients and literature review

Background

Alveolar soft part sarcoma (ASPS) is a rare entity of soft tissue malignancies with uncommon spinal involvements. Surgical management should be the best choice of cure.

Methods

Five patients with spinal ASPS were interviewed retrospectively, where data was collected. The relevant literatures were also systematically examined. Thereafter, patient and surgical data were obtained and pooled for prognostic analysis.

Results

A total of five patients with eight surgeries were reviewed retrospectively, and three patients previously reported were also included. All patients were surgically treated, where five of them underwent additional adjuvant therapies such as chemotherapy, radiotherapy, and targeted therapy in order to manage their local and/or systematic diseases. One patient was lost in follow-up. For the remaining seven patients, the mean follow-up period was 19.7 ± 8.8 months, two succumbed to disease while five were alive at the time of the study.

Conclusions

Surgical management is shown to be the most important and the most effective treatment strategy for spinal ASPS, whereas adjuvant therapies made little impact. The prognostic factors for spinal ASPS are primary or metastatic lesions, neurological status, disease progression, systematic conditions, and resection approaches.

Primary Pulmonary Alveolar Soft-part Sarcoma

Alveolar soft-part sarcoma rarely arises in the lung. Only two patients with tumors that were apparently primary in the lung have been documented in the literature. We report an additional case in a 25-year-old woman. The tumor formed a solitary 5 cm, solid mass in the left perihilar region. Clinical examination, radiologic studies, and follow-up examination of more than 1 year have failed to reveal tumor in an extrapul monary location. The light microscopic appearance was typical for alveolar soft-part sarcoma, and crystalloids were identified in the tumor cells by the periodic acid-Schiff stain and by electron microscopy, confirming the diagnosis. Immunocytochemical studies did not show evidence of myogenic, epithelial, or neuroendocrine differentia tion. Int J Surg Pathol 2(1):57-62, 1994

Alveolar Soft Part Sarcoma-A Histological Surprise in a Male Patient who was Suspected to have Breast Cancer

Alveolar Soft Part Sarcoma (ASPS) is a very rare type of soft tissue sarcoma. Its cell of origin is unclear. It usually presents in the second to fourth decade of life. The most common reported sites of ASPS are the lower extremities, the head and the neck. Because of the rarity of this disease, there is no standard treatment plan. Surgical excision with negative margins is considered as the treatment of choice. We are reporting a rare presentation of ASPS as a male breast lump.

Cytopathology of alveolar soft part sarcoma: a report of 10 cases

BACKGROUND

Alveolar soft part sarcoma (ASPS) rarely is subjected to cytopathologic evaluation. With the exception of some very small series, the literature is limited to case reports. The objectives of the current study were to evaluate the cytomorphology of 10 ASPS cases on fine-needle aspiration (FNA) or imprint cytology, review the literature, and highlight potential diagnostic pitfalls.

METHODS

The authors searched their files for all lesions that were signed out as ASPS or suspicious for ASPS and searched the surgical pathology files for any cases of ASPS that had corresponding cytology. FNA was performed using the standard technique. Scrape preparations were performed on tissues that were sent fresh for frozen section examination.

RESULTS

Ten cases of ASPS were retrieved from 7 patients (male-to-female ratio, 4:3; mean age, 22 years). All had subsequent tissue confirmation. Six specimens were from primary lesions, 3 specimens were from metastases, and 1 intraoperative smear was from a previously aspirated primary mass in a newly diagnosed patient. Anatomic sites of involvement included extremities (5 specimens), trunk/pelvis (3 specimens), oral cavity (1 specimen), and lung (1 specimen). Eight specimens were aspirates, and 2 specimens were intraoperative smears. Nine cases were diagnosed correctly as ASPS/consistent with ASPS, and 1 specimen was diagnosed as "tumor, not otherwise specified". Cytomorphology included variably cellular smears composed of large cells with an enormous amount of finely granular or vacuolated cytoplasm, markedly enlarged nuclei/nucleoli, and bare nuclei. The cytomorphology of some cases revealed a strong similarity to renal cell carcinoma, clear cell type.

CONCLUSIONS

The results of the current study indicated that ASPS has cytomorphology that overlaps with several other neoplasms, including renal cell carcinoma. Nonetheless, the morphologic features, when combined with the clinical presentation, radiologic findings, and ancillary testing, may allow for a specific diagnosis.

Detection of the ASPSCR1?TFE3 gene fusion in paraffin-embedded alveolar soft part sarcomas

AIMS

Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumour with unique morphology and a recurrent, non-reciprocal translocation der(17)t(X;17)(p11.2;q25) leading to the fusion of ASPSCR1 (also known as ASPL) to the transcription factor TFE3. Although diagnosis is straightforward in classical cases, tumours with atypical morphological features may be difficult to classify solely on the basis of conventional histopathology. The aim of this study was to analyse the chromosomal breakpoints in paraffin-embedded tissue.

METHODS AND RESULTS

Three male and two female ASPS patients including one case with uncommon histology were investigated by fluorescence in situ hybridization with split- and fusion-probes. The presence of the resulting ASPSCR1-TFE3 fusion transcripts was assessed by reverse transcriptase-polymerase chain reaction. Hybridization results showed a t(X;17)(p11.2;q25) in all tumours with a duplication of the telomeric part of chromosome Xp. In addition to wild-type TFE3, ASPSCR1-TFE3 fusion transcripts (three type 1 and two type 2 transcripts) were detected in all cases.

CONCLUSIONS

Molecular confirmation of ASPSCR1-TFE3 gene fusion is applicable to routinely processed archival and diagnostic tumour samples and aids in the differential diagnosis of ASPS.

A proposed explanation for female predominance in alveolar soft part sarcoma

BACKGROUND

Alveolar soft-part sarcoma (ASPS) is a rare malignant soft tissue tumor with both clinically and morphologically distinct features. It often involves the extremities of adolescents and young adults and shows a predilection for females. Recently, ASPS was found to have a nonreciprocal der(17)t(X;17) translocation with the corresponding fusion gene located in chromosome 17. Because females have an extra X-chromosome, their likelihood of developing an X;autosome translocation is theoretically double that of males, and thus, this extra X-chromosome is a likely explanation for female predominance of ASPS.

METHODS

The authors used data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) registry program, which included 87 ASPS cases (33 males and 54 females), and published ASPS cases, which included 317 cases (121 males and 196 females), to test our hypothesis. The authors compared the observed proportion of female cases with that expected under the two X-chromosomes-double-risk hypothesis including the consideration of X-inactivation status.

RESULTS

The hypothesis that the fusion gene is not subject to X-inactivation is supported by data (P = 0.6, 0.24, and 0.20 for SEER cases, published cases, and their combination, respectively). In contrast, the competing hypothesis that the fusion gene is subject to X-inactivation is rejected (P = 0.007, < 0.00001, and < 0.00001 for SEER cases, published cases, and their combination, respectively).

CONCLUSIONS

Therefore, the authors found a statistical association between the female predominance observed in ASPS and female possession of an extra X-chromosome/noninactivation of the ASPS X;autosome translocation fusion gene.

Cytologic features of alveolar soft part sarcoma: report of three cases

Alveolar soft part sarcoma (ASPS) is a rare, high-grade, epithelial-like sarcoma that shows characteristic histopathologic findings. Although a chromosomal anomaly that seems specific has been recently described, its diagnosis is based on histologic and ultrastructural features. The tumor shows no specific immunohistologic findings. Cytologic features of three cases of ASPS are presented. Preoperative fine-needle aspiration (FNA) of the primary soft tissue tumor was performed in two cases. In another two, mediastinal and pulmonary and subcutaneous metastatic lesions were aspirated. In all cases the cytologic image was identical with numerous, dissociated, large neoplastic cells with round-to-plasmocytoid morphology. Cytoplasmic fragility and granularity with abundant, atypical, naked nuclei were present. In one case, FNA material was available for ultrastructural studies. It disclosed the characteristic cytoplasmic crystalline structures. A specific cytologic diagnosis of ASPS was given in all cases. In conclusion, ASPS is a rare neoplastic entity that shows a characteristic cytologic image. When accompanied by an adequate clinical context it permits specific preoperative recognition. While immunocytologic studies are helpful to exclude other neoplasms, ultrastructure may result in an exact diagnosis.

MyoD1 and myogenin expression in human neoplasia: a review and update

The MyoD1 family of myogenic nuclear regulatory proteins includes MyoD1/myf3 and myogenin/myf4. These genes and their proteins are critical for skeletal muscle development. Antibodies to MyoD1 and myogenin are relatively recent additions to the armamentarium of the surgical pathologist. This article reviews the biology of the myogenic nuclear regulatory proteins and their use in the diagnosis of rhabdomyosarcoma. Special attention is given to technical and interpretative issues critical to the use of these antibodies in diagnostic pathology.

Primary renal neoplasms with the ASPL-TFE3 gene fusion of alveolar soft part sarcoma: a distinctive tumor entity previously included among renal cell carcinomas of children and adolescents

The unbalanced translocation, der(17)t(X;17)(p11.2;q25), is characteristic of alveolar soft part sarcoma (ASPS). We have recently shown that this translocation fuses the TFE3 transcription factor gene at Xp11.2 to ASPL, a novel gene at 17q25. We describe herein eight morphologically distinctive renal tumors occurring in young people that bear the identical ASPL-TFE3 fusion transcript as ASPS, with the distinction that the t(X;17) translocation is cytogenetically balanced in these renal tumors. A relationship between these renal tumors and ASPS was initially suggested by the cytogenetic finding of a balanced t(X;17)(p11.2;q25) in two of the cases, and the ASPL-TFE3 fusion transcripts were then confirmed by reverse transcriptase-polymerase chain reaction. The morphology of these eight ASPL-TFE3 fusion-positive renal tumors, although overlapping in some aspects that of classic ASPS, more closely resembles renal cell carcinoma (RCC), which was the a priori diagnosis in all cases. These tumors demonstrate nested and pseudopapillary patterns of growth, psammomatous calcifications, and epithelioid cells with abundant clear cytoplasm and well-defined cell borders. By immunohistochemistry, four tumors were negative for all epithelial markers tested, whereas four were focally positive for cytokeratin and two were reactive for epithelial membrane antigen (EMA) (one diffusely, one focally). Electron microscopy of six tumors demonstrated a combination of ASPS-like features (dense granules in four cases, rhomboid crystals in two cases) and epithelial features (cell junctions in six cases, microvilli and true glandular lumens in three cases). Overall, although seven of eight tumors demonstrated at least focal epithelial features by electron microscopy or immunohistochemistry, the degree and extent of epithelial differentiation was notably less than expected for typical RCC. We confirmed the balanced nature of the t(X;17) translocation by fluorescence in situ hybridization in all seven renal tumors thus analyzed, which contrasts sharply with the unbalanced nature of the translocation in ASPS. In summary, a subset of tumors previously considered to be RCC in young people are in fact genetically related to ASPS, although their distinctive morphological and genetic features justify their classification as a distinctive neoplastic entity. Finally, the finding of distinctive tumors being associated with balanced and unbalanced forms of the same translocation is to our knowledge, unprecedented.

Structural variations of collagen in normal and pathological tissues: role of electron microscopy

The spectrum of ultrastructural appearances assumed by collagen in normal and pathological tissues is illustrated using techniques of thin section transmission electron microscopy and computer-assisted analysis. The normal fibrillar collagen types are described in order to provide a basis for comparing other normal and abnormal forms. In normal tissues, the anchoring fibril and basal lamina (basement membrane) represent tissue structures largely containing collagen but differing significantly in organisation from normal types I to III fibrillar collagen. In pathological tissue, deviations from normal fine structure are reflected in abnormal aggregates of collagen fibrils (amianthoid and skeinoid fibres) and abnormalities in fibril diameter and cross-sectional profile. Fibrous and segment long-spacing collagen represent two further organisational variants of collagen, the former found widely in pathological tissues, the latter very rarely. Much remains to be discovered about these abnormal collagen variants-their mode of formation, the cells that produce them, and their roles. They also present a challenge for the collagen biologist formulating hypotheses of collagen fibril assembly and molecular organisation.

Immunohistochemical profile of myogenin and MyoD1 does not support skeletal muscle lineage in alveolar soft part sarcoma

BACKGROUND

The histogenesis of alveolar soft part sarcoma remains elusive. Myogenic origin is favored, although conflicting data on immunohistochemical demonstration of muscle-associated markers exist. Myogenin and MyoD1, transcription factors of the myogenic determination family, have crucial roles in commitment and differentiation of mesenchymal progenitor cells to myogenic lineage and in maintenance of skeletal muscle phenotype. Their immunohistochemical detection is specific in characterization of rhabdomyosarcoma.

METHODS

Antibodies for myogenin, MyoD1, desmin, and muscle-specific actin were employed on a large series of cases (n = 19) of formalin-fixed, paraffin-embedded alveolar soft part sarcoma.

RESULTS

Minimal scattered nuclear staining was seen with myogenin. All cases had pronounced, nonspecific granular cytoplasmic immunostaining with MyoD1; nuclei were negative. All tumors were negative for desmin and muscle-specific actin. Ultrastructural study in 10 cases failed to reveal features of skeletal muscle differentiation.

CONCLUSIONS

Cytoplasmic staining with MyoD1 in alveolar soft part sarcoma may correspond to cross-reactivity with an undetermined cytoplasmic antigen. The lack of immunostaining with myogenin, MyoD1, desmin, and muscle-specific actin provides evidence against a myogenic origin for alveolar soft part sarcoma.

Alveolar soft part sarcoma of the head and neck region

Alveolar soft part sarcoma is a soft tissue malignancy most often found in the extremities of young adults; when these tumors arise in the head and neck area, they usually appear in the orbit or the tongue. Their initial behavior is relatively indolent, but over time a sizable number of these tumors recur locally and metastasize; as such, they are best regarded as fully malignant neoplasms. The derivation of these tumors remains uncertain: while some have suggested that these are tumors of muscle origin and others have postulated a neuroendocrine origin, the evidence accumulated to date is conflicting, and so these neoplasms continue to be regarded as tumors of uncertain origin. Surgical excision is the mainstay of therapy.

Alveolar soft-part sarcoma: a review of the pathology and histogenesis

The descriptive designation, alveolar soft-part sarcoma, continues to be used for this uncommon soft-tissue malignancy because an acceptable hypothesis for its histogenesis has not been advanced, despite studies with electron microscopy and immunohistochemistry. These techniques have, nevertheless, provided significant information that is useful in the differential diagnosis of the tumor and pertinent in speculation concerning its nature. The most intriguing ultrastructural feature is the secretory process that culminates in the formation of the distinctive cytoplasmic crystals. Myogenic differentiation has been favored in a number of recent reports on the basis of immunohistochemical findings and the presence of the crystals does not rule out the possibility, but accounts of immunoreactivity for the myogenic regulatory protein MyoD1 have not been confirmed in subsequent studies or in the authors' own staining of six cases.

Alveolar soft part sarcoma: review of nine cases including two cases with unusual histology

AIM

Alveolar soft part sarcoma is a very rare tumour. Nine cases are reviewed in order to identify new aspects of this tumour.

METHODS AND RESULTS

The clinical course, histological, immunohistochemical and ultrastructural features of nine cases of alveolar soft part sarcoma were reviewed. Proliferative activity and p53 protein accumulation were assessed immunohistochemically. The patients were aged between 18 and 70 years. In the cases with sufficient follow-up, survival was variable with two patients dying within 5 months and four alive at 4 years. Histologically all tumours had an alveolar component but one case also had a spindle component and another case had a pseudoglandular pattern. Six cases showed desmin immunoreactivity, one was muscle-specific actin positive, two were positive for S100 protein and three were positive for vimentin. MIB-1 immunostaining was seen in up to 35% of cells. Two cases showed p53 protein accumulation.

CONCLUSIONS

There appeared to be no correlation between short term survival (4 years or less) and clinical presentation, adjuvant treatment, tumour size, histological grade, vascular invasion by tumour, proliferative index, or p53 protein accumulation. Although unusual, spindle cell or pseudoglandular components can be seen in alveolar soft part sarcoma.

Fine needle aspiration (FNA) in the diagnosis of soft tissue tumours; a review of 22 years experience

FNA plays an important role in preoperative diagnosis of soft tissue tumours. A close clinical/morphologic cooperation is essential. FNA should be performed on the most accessible part of the tumour, avoiding penetration of the deep portions of the tumour. Needles 0.7 mm (22 G) are recommended. For deep lesions, needles with a stylet should be used. After the FNA, tattooing of the aspiration channel is recommended, and the channel is surgically removed together with the tumour, if a sarcoma. Material from the FNA can be used for additional examinations, i.e. electron microscopy, immunohistochemistry, DNA ploidy analysis and chromosomal analysis. Those techniques are of great importance in the differential diagnosis, particularly in the paediatric small/round cell tumours. The majority of sarcomas can be defined as low grade or high grade malignant in FNA. For malignancy grading the following parameters are used: cellularity, pleomorphism, chromatin pattern, nucleolar structure, mitotic figures and necroses. Cytodiagnostic details of the most common soft tissue tumours and their differential diagnoses are presented.

Alveolar soft-part sarcoma: evidence for its myogenic origin and for the involvement of 17q25

A typical case of alveolar soft-part sarcoma was examined using ultrastructural, immunohistochemical and cytogenetic methods. Immunohistochemical stains were performed on frozen sections and showed strong desmin expression with the three anti-desmin antibodies used. In addition, the tumour cells were weakly positive for vimentin and myosin. Neural markers were negative. Chromosomal analysis showed consistent involvement of 17q25--an abnormality which has been reported in another alveolar soft-part sarcoma. The histogenesis of alveolar soft-part sarcoma is still debatable but our findings support a myogenic origin. The finding of an apparently identical chromosomal abnormality in two of three thus far examined cases of alveolar soft-part sarcoma is of interest and must await further confirmation, but it may result in the identification of a chromosomal marker for this enigmatic tumour and thus pave the way for further molecular elucidation.

Alveolar soft part sarcoma: an unusually long interval between presentation and brain metastasis

While alveolar soft part sarcoma is an uncommon soft tissue tumor known for late metastases to lung, bone, and brain, and interval of 33 years between primary presentation and development of brain metastasis has not been described. We document a patient with a removal of an alveolar soft part sarcoma from the pectoralis major muscle at the age of 10 years, a lung metastasis at the age of 31 years, and brain and renal masses at the age of 43 years. The patient received surgical resections each time, but never radiotherapy or chemotherapy. He is currently alive and well. Immunohistochemistry, karyotypic analysis, flow cytometry, and gene expression were analyzed on primary tumor and established cell cultures in the hopes of further elucidating the histogenesis of this unusual neoplasm.

Primary alveolar soft part sarcoma of the tongue of an elderly man. A case report and review of the literature

A 64-year-old black man had a primary alveolar soft part sarcoma of the tongue. It is unusual for this rare tumor to develop in this site in the elderly age group. The patient survived nearly 3 years with disease. When the patient expired, a complete autopsy was performed. The biopsy material of the primary tumor showed characteristic light microscopic appearance, intracellular periodic acid-Schiff positive inclusions after diastase reaction, and electron microscopic presence of crystals. Immunohistochemistry for neuron-specific enolase was positive. The autopsy confirmed widespread visceral and lymphatic metastases. The atypical features of this case, including the site of the primary lesion, age of the patient at diagnosis, immunohistochemistry of the tumor, and natural history of this neoplasm, suggest that alveolar soft part sarcoma may behave differently when arising in an extraskeletal site, and could possibly have a different histogenesis from the typical alveolar soft part sarcoma found in a younger population.

Epithelioid sarcoma. Flow cytometric study of DNA content and regional DNA heterogeneity

The DNA content and regional DNA heterogeneity in correlation with clinicopathologic parameters and patient survival were investigated in epithelioid sarcoma. Such neoplasms preponderantly manifest diploid DNA content and a remarkably stable intratumoral and intertumoral DNA content. Small tumor size (less than 5.0 cm) and low S-phase fraction (less than 5%) were significant prognostic factors in this study. Ploidy status, mitotic rate, age, and postsurgical treatment were not significantly correlated with survival.

Alveolar soft part sarcoma of the pulmonary vein

Alveolar soft part sarcoma of the lung seen in a 42-year-old female is reported. In the partial pneumonectomy specimen, there was a 3 x 2.5 cm tumor arising from the pulmonary vein at the level of the right lung hilus, with tumor thrombus formation. The transition between the tumor and venous smooth muscle layer was microscopically confirmed. At autopsy, performed 18 months after surgery, metastases were noted in the left lung and brain. No primary focus was identified in the soft tissue. The alveolus-forming clear tumor cells contained diastase-resistant periodic acid-Schiff-reactive granules. Immunohistochemically, granular cytoplasmic reactivities with monoclonal antibodies against pan-actin and alpha-sarcomeric actin were demonstrated, whereas other muscle markers such as desmin, alpha-smooth muscle actin, myoglobin, fast skeletal myosin, and the mm-isozyme of creatine kinase were negative. Ultrastructurally, crystallized structures were occasionally identified in the membrane-bound, electron lucent granules, which often filled the tumor cell cytoplasm. The muscle cell nature of the neoplasm is discussed.

Morphological and cytogenetic studies of angiosarcoma in Stewart-Treves syndrome

A morphological and cytogenetic analysis of a multifocal angiosarcoma in a typical case of Stewart-Treves syndrome is reported. The morphological analysis indicated differentiation along both blood and lymph vessel endothelium lines. By light and electron microscopy there were areas with well-developed erythrocyte-containing, capillary-like vessels and poorly differentiated areas with abortive vascular formations. In these the endothelium revealed immunoreactivity to factor VIII RAg, binding of Ulex europaeus I and Psophocarpus tetragonolobus agglutinin lectins, Weibel-Palade bodies ultrastructurally and presented a continuous enclosing external lamina and immunoreactivity for laminin and collagen IV, all features of blood-vessel differentiation. There were also lymphangioma-like areas as well as poorly differentiated areas where the immunohistochemical, lectin-binding and ultrastructural features were compatible with a lymph vessel differentiation. Cytogenetic analysis of cultured tumour cells revealed chromosome counts in the diploid region. About 40% of the cells analysed had a normal diploid karyotype. The remaining cells showed a multitude of mainly nonclonal structural alterations; 17 unique marker types resulting from different translocations and deletions were observed. There were also a few cells with clonal numerical deviations showing monosomy 22, monosomy X and trisomy 2 respectively. It is of interest that the losses of chromosome 22 and the X chromosome also have been observed in Kaposi's sarcoma and that the PD-ECGF gene, a novel angiogenetic factor, has been mapped to chromosome 22.

Fine-needle aspiration cytology of alveolar soft-part sarcoma

Alveolar soft-part sarcoma (ASPS) is a rare soft-tissue tumor. Few cases have been reported in the aspiration cytology literature. We discuss the fine-needle aspiration (FNA) cytologic features of ASPS in four patients. The smears were characterized by single cells and clusters of cells associated with thin-walled vasculature, resulting in a distinct pseudoalveolar pattern. The cells had abundant granular cytoplasm and large round nuclei with prominent central nucleoli. Binucleated and occasional multinucleated cells were present. Numerous stripped tumor nuclei were a consistent feature. Periodic acid-Schiff (PAS)-positive diastase-resistant granules were demonstrable within the intact and fragmented cytoplasm. Electron microscopy of aspirated material identified granules and crystals with the characteristic lattice pattern. To conclude, the FNA cytologic features of ASPS are characteristic. Confirmation by special stains and electron microscopy of FNA material is possible. The differential diagnostic considerations include renal cell carcinoma, paraganglioma, granular cell tumor, clear cell sarcoma, and epithelioid sarcoma.

Alveolar soft part sarcoma: a case report with immunohistochemical study

We report herein, a rare case of a 28 year old Japanese man with alveolar soft part sarcoma. The patient noticed a rapidly growing mass in the inner aspect of his left thigh and a smooth-surfaced, hard nodule revealing bruit on auscultation was found on physical examination. An angiogram showed dense neovascularity from the left profunda femoris artery. Histopathologically, the tumor was composed of nests of tumor cells with hyperchromatic nuclei and vesicular cytoplasm arranged in an alveolar fashion and a histopathologic diagnosis of alveolar soft part sarcoma was made. Immunohistochemically, the tumor cells had desmin and vimentin immunoreactants in the cytoplasm, suggesting muscle origin.

Synovial sarcoma. A DNA flow cytometric study

The relationship between DNA content, clinicopathologic findings, and patient survival in synovial sarcoma was investigated. Patient age at diagnosis (P less than 0.001), tumor size (P less than 0.001), and ploidy status (P less than 0.003) correlated significantly with patient survival. A marginally significant correlation between mitotic count and patient survival was also observed (P = 0.04). Histologic subtypes (monophasic versus biphasic), mitotic count, and S-phase by flow cytometry had no significant influence on the clinical outcome of patients with synovial sarcoma in this study. The authors conclude that DNA ploidy analysis is a significant objective probe in the prognostication of patients with synovial sarcoma.

A cell culture, chromosomal and quantitative DNA analysis of a metastatic epithelioid sarcoma. Deletion 1p, a possible primary chromosomal abnormality in epithelioid sarcoma

The chromosomal banding pattern and the in vitro growth characteristics of a metastatic epithelioid sarcoma are described. The cultured tumor cells retained growth characteristics as well as ultrastructural and immunohistochemical properties similar to the cells of the primary tumor. Cytogenetic analysis revealed a modal range in the diploid-hypodiploid region, a finding which was corroborated by quantitative DNA determinations of both the primary tumor and a lymph node metastasis. Fourteen different marker chromosomes were identified. The most frequent clonal rearrangement was a 1p-marker resulting from a short arm terminal deletion, i.e., del (1) (p21-22). A similar 1p- marker has previously been observed in an established epithelioid sarcoma cell line. The finding of an apparently identical 1p-marker in two of two analyzed epithelioid sarcomas suggests that this rearrangement may be a primary cytogenetic abnormality in epithelioid sarcoma. An elevated ras p21 expression was demonstrated using immunohistochemical methods. The possible involvement of the N-ras gene and/or a tumor suppressor in the 1p deletion is considered.

Alveolar soft part sarcoma. A clinicopathologic and immunohistochemical study of 12 cases

Twelve cases of alveolar soft part sarcoma (ASPS) were reviewed. Seven of them arose primarily in the lower extremities, three in the head and neck region, and two in other parts. ASPSs in the head and neck region occurred in children before 10 years of age, whereas ASPSs in the other regions occurred in rather older patients. Moreover, ASPSs of the head and neck were relatively small in size, and were diagnosed earlier than those in other regions. Histologically, six cases (including all the head and neck cases) contained considerable area of small and indistinct alveolar structures. Four cases showed remarkable cellular pleomorphism. Immunohistochemical demonstration of vimentin, desmin, the beta-subunit of enolase and the MM isozyme of creatine kinase, together with the absence of immunoreactive cytokeratin, supported the myogenic nature of this rare tumor. A small number of S-100 protein-positive tumor cells were also observed. Follow-up data for these cases disclosed that the tumors containing considerable area of small alveoli and uniform small tumor cells formed distant metastases at an early stage.

Cytoskeletal properties of alveolar soft part sarcoma

The immunohistochemical expression of cytoskeletal proteins in alveolar soft part sarcoma (ASPS) was studied by light and electron microscopy. Of the five cases examined by the avidinbiotin-peroxidase complex method, variable numbers of immunoreactive cells for desmin were found in three, for vimentin in two, for muscle-specific actins in three, and for alpha-smooth muscle actin in four. Immunoelectron microscopic study demonstrated that desmin and vimentin were localized on whorled bundles of intermediate filaments in the perinuclear cytoplasm. In addition, a few dispersed intermediate filaments became evident in specimens treated with saponin and fixed with tannic acid. These immunohistochemical results indicate that a few tumor cells of ASPS may express some properties of the cytoskeleton of smooth muscle cells in addition to those of skeletal muscle cells. Considering the discrepancies reported in the actin isoforms demonstrated in myogenic tumors, we conclude that ASPS is probably a peculiar, primitive myogenic tumor that does not show any distinctive features of rhabdomyogenic or leiomyogenic differentiation.

DNA cytometry of soft tissue tumours with TV image-analysis system

We examined 69 soft tissue tumours for DNA content. Altogether 42 aspiration cytology and 27 imprint Feulgen-stained smears, each verified by histology, were analysed and the results evaluated with Böckings's algorithm. Except one false negative case (extramedullary ependymoma) 43 malignant and 25 benign soft tissue tumours could clearly be separated on the basis of their DNA content. The sensitivity of the positive cases (suspicious and malignant) came up to 97.7% with a false negative ratio of 2.2% while the sensitivity of the negative cases (benign) proved to be 75% with a 0% false positivity ratio. Cytometry is a useful aid in aspiration cytology diagnostics of soft tissue tumours particularly when their benign or malignant character is to be determined because the primary surgical therapy and consequently the further fate of patient, too, depend on the precise cytological diagnosis.

Rhabdomyosarcoma in middle-aged and elderly individuals

In a review of a national series of malignant tumors in middle-aged and elderly individuals (over 40 years of age), in all 107 cases primarily diagnosed and reported to the Swedish Cancer Registry as rhabdomyosarcomas during the period 1972-1981, 4 cases were accepted as botryoid, embryonal or alveolar rhabdomyosarcoma, using light-microscopic criteria for the diagnosis. An electron-microscopic and immunohistochemical analysis was performed on the 4 cases along with 7 cases of botryoid, embryonal and alveolar rhabdomyosarcoma in patients of over 40 years of age obtained from our own files. Rhabdomyoblastic differentiation was established ultrastructurally by the presence of myofilaments and Z-like densities in 10 of these 11 cases. There were tumor cells in the formaldehyde-fixed, paraffin-embedded material which were positively stained for desmin in all cases, for myoglobin in 7/11 cases, for vimentin in 5/11 cases and for actin in all cases, using monoclonal antibodies. The demonstration of desmin by the monoclonal antibody which was used on the formaldehyde-fixed, paraffin-embedded material is of particular value in the diagnosis of rhabdomyosarcoma. Another tumor, located in the minor pelvis, lacked the light-microscopic features of botryoid, embryonal or alveolar rhabdomyosarcoma, but presented ultrastructural and immunohistochemical evidence of a rhabdomyoblastic differentiation. This tumor was epithelioid in appearance and shared features with alveolar soft part sarcoma. The label epithelioid rhabdomyosarcoma is proposed for this tumor. Nine pleomorphic sarcomas were selected from the national series as possible pleomorphic rhabdomyosarcomas because of the presence of ribbon-shaped tumor cells with an eosiniphilic cytoplasm. There was no electron-microscopic or immunohistochemical evidence of a myogenic differentiation in any of these 9 tumors. The present investigation indicates that a pleomorphic type of rhabdomyosarcoma, indistinguishable from embryonal, botryoid and alveolar rhabdomyosarcoma, is extremely rare or non-existent.

Alveolar soft part sarcoma. Assessment of immunohistochemical demonstration of desmin using paraffin sections and frozen sections

The many different theories on the histogenesis of alveolar soft part sarcoma (ASPS) have caused great confusion. Owing to the recent rapid advance in immunohistochemical studies, two major hypotheses have been proposed. One group of researchers supports the idea that ASPS shows myogenic differentiation, while the other group opposes the idea. This confrontation is essentially one between a group that believes in the immunohistochemically demonstrated presence of desmin in ASPS and a group that denies it. In the present study we detected desmin in 6 of 10 formalin-fixed paraffin sections (although there were differences due to the use of five commercially available types of anti-desmin antibodies). When acetone-fixed paraffin sections and periodate-lysin-paraformaldehyde (PLP)-fixed frozen sections were used in one and three cases, respectively, they were found to be desmin positive, regardless of the type of antibody. The consistent positivity for all anti-desmin antibodies in the cases treated with acetone or PLP is very suggestive of a myogenous origin of ASPS. It is important to take into consideration the fact that formalin-fixed paraffin sections are not very suitable for immunohistochemical study of desmin.

Extraspinal ependymoma in the sacrococcygeal region. A case report with ultrastructural, immunohistochemical and cytophotometric studies

We describe on a primary, subcutaneous sacrococcygeal ependymoma presenting in a young female patient. Detailed immunohistochemical and electron microscopic examinations were performed. Out of the 40 similar cases reported in literature this is the first in which the determination of DNA content was also used to predict biological behaviour. The tumour proved to be aneuploid with low proliferative capacity in spite of absent histological signs of malignancy. It is suggested that DNA determination may be helpful in establishing prognosis and that it may contribute to a better understanding of the biological behaviour of this tumour.