T-regulatory cells predict clinical outcome in soft tissue sarcoma patients: a clinico-pathological study.

BACKGROUND: Soft tissue sarcomas (STS) are generally considered non-immunogenic, although specific subtypes respond to immunotherapy. Antitumour response within the tumour microenvironment relies on a balance between inhibitory and activating signals for tumour-infiltrating lymphocytes (TILs). This study analysed TILs and immune checkpoint molecules in STS, and assessed their prognostic impact regarding local recurrence (LR), distant metastasis (DM), and overall survival (OS). METHODS: One-hundred and ninety-two surgically treated STS patients (median age: 63.5 years; 103 males [53.6%]) were retrospectively included. Tissue microarrays were constructed, immunohistochemistry for PD-1, PD-L1, FOXP3, CD3, CD4, and CD8 performed, and staining assessed with multispectral imaging. TIL phenotype abundance and immune checkpoint markers were correlated with clinical and outcome parameters (LR, DM, and OS). RESULTS: Significant differences between histology and all immune checkpoint markers except for FOXP3+ and CD3-PD-L1+ cell subpopulations were found. Higher levels of PD-L1, PD-1, and any TIL phenotype were found in myxofibrosarcoma as compared to leiomyosarcoma (all p < 0.05). The presence of regulatory T cells (Tregs) was associated with increased LR risk (p = 0.006), irrespective of margins. Other TILs or immune checkpoint markers had no significant impact on outcome parameters. CONCLUSIONS: TIL and immune checkpoint marker levels are most abundant in myxofibrosarcoma. High Treg levels are independently associated with increased LR risk, irrespective of margins.

Oncolytic adenovirus and doxorubicin-based chemotherapy results in synergistic antitumor activity against soft-tissue sarcoma.

Despite originating from several different tissues, soft-tissue sarcomas (STS) are often grouped together as they share mesenchymal origin and treatment guidelines. Also, with some exceptions, a common denominator is that when the tumor cannot be cured with surgery, the efficacy of current therapies is poor and new treatment modalities are thus needed. We have studied the combination of a capsid-modified oncolytic adenovirus CGTG-102 (Ad5/3-D24-GMCSF) with doxorubicin, with or without ifosfamide, the preferred first-line chemotherapeutic options for most types of STS. We show that CGTG-102 and doxorubicin plus ifosfamide together are able to increase cell killing of Syrian hamster STS cells over single agents, as well as upregulate immunogenic cell death markers. When tested in vivo against established STS tumors in fully immunocompetent Syrian hamsters, the combination was highly effective. CGTG-102 and doxorubicin (without ifosfamide) resulted in synergistic antitumor efficacy against human STS xenografts in comparison with single agent treatments. Doxorubicin increased adenoviral replication in human and hamster STS cells, potentially contributing to the observed therapeutic synergy. In conclusion, the preclinical data generated here support clinical translation of the combination of CGTG-102 and doxorubicin, or doxorubicin plus ifosfamide, for the treatment of STS, and provide clues on the mechanisms of synergy.

Uterine leiomyosarcoma diffusely express disialoganglioside GD2 and bind the therapeutic immunocytokine 14.18-IL2: implications for immunotherapy.

Uterine leiomyosarcoma comprises <1 % of uterine malignancies and is known for its clinically aggressive course. Extrapelvic recurrences are common and often lethal. No adjuvant therapies have been shown to significantly improve overall survival, highlighting the need for new and novel therapies. Our objective was to determine whether GD2-specific immunocytokine therapy may be explored for the treatment for uterine leiomyosarcoma. To do so, frozen tissue sections were obtained from the Gynecologic Oncology Group tumor bank and evaluated by immunohistochemistry (IHC) for GD2 expression using both the parent mouse monoclonal antibody 14G2A and immunocytokine 14.18-IL2 generated from the 14G2A sequence. Immunoreactivity was detected by avidin-biotin complex with DAB substrate. Specimens were reviewed by a pathologist with light microscopy and classified as negative, 1+, 2+ or 3+, compared to human melanoma cells as positive control and tissue incubated in the absence of primary antibody as negative control. GD2 was diffusely present in all evaluable samples. 10 tumors (67 %) demonstrated 3+ IHC intensity for GD2, two tumors (13 %) demonstrated 2+ intensity, and 3 (20 %) tumors demonstrated 1+ intensity. Eleven cases had sufficient tissue to assess 14.18-IL2 binding. All 11 cases bound 14.18-IL2 in a pattern identical to the parent antibody. Uterine leiomyosarcoma diffusely express GD2 and bind the therapeutic immunocytokine 14.18-IL2. This warrants further exploration to determine whether immunocytokine therapy may have a clinical role in the management of these aggressive tumors.

Sarcomas other than Kaposi sarcoma occurring in immunodeficiency: interpretations from a systematic literature review.

PURPOSE OF REVIEW: In immunodeficiency, an increased sarcoma risk is confirmed for Kaposi's sarcoma. Whether rates of other sarcoma subtypes are elevated in the setting of immunodeficiency is not known. We therefore reviewed published case reports on HIV and AIDS patients and organ transplant recipients with sarcomas. For comparison, we assessed sarcomas in the U.S. general population using Surveillance Epidemiology End Results (SEER) data. RECENT FINDINGS: A total of 176 non-Kaposi sarcoma were identified, 75 in people with HIV and AIDS and 101 in transplant recipients. Leiomyosarcomas (n = 101) were the most frequently reported sarcomas, followed by angiosarcomas (n = 23) and fibrohistiocytic tumors (n = 17). Leiomyosarcomas were reported with two age peaks, in children and young adults. Epstein-Barr virus (EBV) was detected in the tumor cells in 85 and 88% of leiomyosarcomas in HIV-infected people and transplant recipients, respectively. Angiosarcomas and fibrohistiocytic tumors were most frequently reported in men. Among kidney transplant recipients, 20% of sarcomas arose at the site of an arteriovenous fistula. In comparison, leiomyoscarcomas, angiosarcomas, and fibrohistiocytic tumors comprised 16.9, 3.8, and 18.7% of sarcomas in the U.S. general population. SUMMARY: Leiomyosarcoma and angiosarcoma may occur disproportionately in immunodeficiency. Leiomyosarcomas appear causatively linked to EBV, whereas angiosarcomas might be correlated with an arteriovenous fistula. Additional studies are necessary to understand the contribution of immunodeficiency to the cause of these sarcomas.

Leiomyosarcoma mimicking acute appendicitis: a cautionary tale!

Appendiceal neoplasms are rare, occurring in <1.4% of all appendicectomy specimens. Carcinoid tumours and adenocarcinomas comprise the majority of cases, however, lymphomas or sarcomas may also arise within the appendix. Appendiceal leiomyosarcomas are rare and to date, there remains a relative dearth of cases reported in the literature. Leiomyosarcomas are derived from the smooth muscle cells or mesenchymal stem cells committed to this line of differentiation. However, their pathogenesis and underlying genetic mechanism remains to be fully elucidated. Unbalanced karyotypic defects are the only shared features observed across different leiomyosarcoma subtypes. Children with AIDS have a higher incidence compared with adults, where the main pathology in individuals with HIV is Kaposi's sarcoma and B-cell lymphoma. Although surgical excision with clear margins remains the treatment of choice, a good response to treatment with gemcitabine, docetaxel and trabectedin has been observed. The authors present the case of a 23-year-old female presenting to the emergency department with acute appendicitis. She underwent a laparoscopic converted to an open appendectomy. Her operation was complicated by a pelvic collection requiring percutaneous drainage and an ileus. Histopathological examination confirmed the diagnosis of a leiomyosarcoma, a rare mesenchymal tumour presenting in individuals with immune suppression. HIV serology was positive and she commenced anti-retroviral therapy. She remains under review in the Department of HIV Medicine.

The Adaptive and Innate Immune Cell Landscape of Uterine Leiomyosarcomas.

Reactivation of the anti-tumor response has shown substantial progress in aggressive tumors such as melanoma and lung cancer. Data on less common histotypes are scanty. Immune checkpoint inhibitor therapy has been applied to few cases of uterine leiomyosarcomas, of which the immune cell composition was not examined in detail. We analyzed the inflammatory infiltrate of 21 such cases in high-dimensional, single cell phenotyping on routinely processed tissue. T-lymphoid cells displayed a composite phenotype common to all tumors, suggestive of antigen-exposure, acute and chronic exhaustion. To the contrary, myelomonocytic cells had case-specific individual combinations of phenotypes and subsets. We identified five distinct monocyte-macrophage cell types, some not described before, bearing immunosuppressive molecules (TIM3, B7H3, VISTA, PD1, PDL1). Detailed in situ analysis of routinely processed tissue yields comprehensive information about the immune status of sarcomas. The method employed provides equivalent information to extractive single-cell technology, with spatial contexture and a modest investment.

The adequacy of tissue microarrays in the assessment of inter- and intra-tumoural heterogeneity of infiltrating lymphocyte burden in leiomyosarcoma.

The characterisation and clinical relevance of tumour-infiltrating lymphocytes (TILs) in leiomyosarcoma (LMS), a subtype of soft tissue sarcoma that exhibits histological heterogeneity, is not established. The use of tissue microarrays (TMA) in studies that profile TIL burden is attractive but given the potential for intra-tumoural heterogeneity to introduce sampling errors, the adequacy of this approach is undetermined. In this study, we assessed the histological inter- and intra-tumoural heterogeneity in TIL burden within a retrospective cohort of primary LMS specimens. Using a virtual TMA approach, we also analysed the optimal number of TMA cores required to provide an accurate representation of TIL burden in a full tissue section. We establish that LMS have generally low and spatially homogenous TIL burdens, although a small proportion exhibit higher levels and more heterogeneous distribution of TILs. We show that a conventional and practical number (e.g. ≤3) of TMA cores is adequate for correct ordinal categorisation of tumours with high or low TIL burden, but that many more cores (≥11) are required to accurately estimate absolute TIL numbers. Our findings provide a benchmark for the design of future studies aiming to define the clinical relevance of the immune microenvironments of LMS and other sarcoma subtypes.

PD-L1 Expression and Tumor-infiltrating Lymphocytes in Uterine Smooth Muscle Tumors: Implications for Immunotherapy.

Immunotherapies targeting the PD-1/PD-L1 checkpoint axis are of growing interest for the treatment of mesenchymal neoplasms. However, PD-L1 expression and tumor-associated lymphocytes have not been well-investigated in uterine smooth muscle tumors. Forty-nine uterine smooth muscle tumors (23 leiomyosarcomas, 8 smooth muscle tumors of uncertain malignant potential [STUMP], 7 atypical leiomyomas, and 11 benign leiomyomas) were evaluated for tumoral and tumor-associated immune PD-L1 expression and tumor-associated T-cell infiltration. ALK immunohistochemistry was performed to exclude inflammatory myofibroblastic tumors. Tumor PD-L1 expression was seen in 70% of leiomyosarcomas and 14% of atypical leiomyomas; no cases of STUMP or benign leiomyoma demonstrated tumoral PD-L1. PD-L1 positivity was seen in tumor-associated immune cells in 78% of leiomyosarcomas, 25% of STUMP, no cases of atypical leiomyomas, and 9% of benign leiomyomas. Of the 23 leiomyosarcomas, 15 (65%) had a combined positive score ≥1, while of the 26 other uterine smooth muscle tumors, only 2 (8%) had a combined positive score ≥1. Tumor-associated CD8+ cells were highest among leiomyosarcomas (mean: 87/high-power fields vs. 17/high-power fields for nonleiomyosarcomas), and were significantly associated with PD-L1 expression. One PD-L1, CD8-enriched leiomyosarcoma showed an ALK overexpression suggesting possible classification as inflammatory myofibroblastic tumor, but otherwise lacked morphologic features of this entity. Leiomyosarcomas demonstrate significantly higher PD-L1 expression and cytotoxic T-cell infiltration when compared with other uterine smooth muscle tumors. These data suggest the possibility that treatment with targeted immunotherapy may be appropriate in a selected population of patients with leiomyosarcoma and, potentially, in related tumors bearing ALK rearrangements.

Clinical phase I intratumoral administration of two recombinant ALVAC canarypox viruses expressing human granulocyte-macrophage colony-stimulating factor or interleukin-2: the transgene determines the composition of the inflammatory infiltrate.

Immunotherapy employs cytokines for modifying local inflammatory reactions. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to activate dendritic cells, macrophages, and granulocytes leading to clinical trials using GM-CSF-based cancer vaccine approaches. Interleukin-2 (IL-2) is an important T cell stimulatory cytokine approved as exogenous antitumor agent. The ALVAC viral vector system uses a recombinant canarypox virus for local gene expression. We report a phase I clinical trial using intratumoral administration of ALVAC GM-CSF or ALVAC IL-2 in skin metastases of melanoma or leiomyosarcoma. ALVAC GM-CSF and ALVAC IL-2 were injected at 107.12 and 106.92, 50% cell culture infectious dose in eight metastases with acceptable tolerability. Local and systemic inflammatory reactions were observed. The transgene determined the local infiltrate: GM-CSF induced monocyte and macrophage enrichment of the peritumoral inflammatory infiltrate, whereas IL-2 increased local T lymphocytes. Stable disease of injected lesions was seen after ALVAC GM-CSF application, whereas ALVAC IL-2 treatment led to partial regression in three out of eight injected tumors, accompanied by decreased expression of melanocytic antigens. Local GM-CSF expression could be induced. In summary, ALVAC GM-CSF and ALVAC IL-2 injections are safe and can mediate local biologic and immunologic effects.

Multiepitope CD8(+) T cell response to a NY-ESO-1 peptide vaccine results in imprecise tumor targeting.

The cancer-testis antigen NY-ESO-1 is one of the most promising candidates for generic vaccination of cancer patients. Here we analyzed the CD8(+) T cell response to a NY-ESO-1 peptide vaccine composed of the two previously defined peptides 157-165 and 157-167, administered with GM-CSF as a systemic adjuvant. The NY-ESO-1 peptide vaccine elicited a CD8(+) T cell response directed against multiple distinct epitopes in the 157-167 region, as revealed by using A2/peptide multimers incorporating overlapping A2 binding peptides in this region. However, only a minor fraction of the elicited CD8(+) T cells, namely those recognizing the peptide 157-165 with sufficiently high functional avidity, recognized the naturally processed target on NY-ESO-1(+) tumor cells. In contrast, the majority of peptide 157-165-specific CD8(+) T cells exhibited lower functional avidity and no tumor reactivity. In addition, vaccine-elicited CD8(+) T cells specific for other overlapping epitopes in the 157-167 region failed to significantly recognize NY-ESO-1-expressing tumor targets. Thus, because of the complexity of the CD8(+) T cell repertoire that can be elicited by vaccination with synthetic peptides, a precise definition of the targeted epitope, and hence, of the corresponding peptide to be used as immunogen, is required to ensure a precise tumor targeting.

Primary ovarian leiomyosarcoma: a review of the clinical and immunohistochemical features of the rare tumor.

UNLABELLED: Primary pure ovarian leiomyosarcomas constitute a malignant subgroup of ovarian smooth muscle tumors which comprise only 1% of ovarian tumors. Their origin, etiology, histologic features, clinical behavior, and optimal treatment are still obscure. Malignant behavior is almost always associated with any 2 of coagulative necrosis, cellular atypia, and mitotic index greater than 10. Immunohistochemical and electron microscopic evaluations may improve diagnostic accuracy. Traditionally, International Federation of Gynecology and Obstetrics (FIGO) staging and treatment of ovarian sarcomas have been the same as for epithelial ovarian carcinomas. Although surgery was performed for all cases, the extent of surgery is debatable. Benefit and modality of adjuvant therapy is controversial. The prognosis of primary pure ovarian leiomyosarcomas is extremely poor depending on tumor stage, tumor size, grade, and mitotic index and mostly recurs in abdomen and pelvis. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader should be able to state how rare primary ovarian leiomyosarcoma (POLMS) is, explain that because of its rarity the best diagnostic and treatment modalities are not conclusive, and recall that the authors reviewed the literature to bring the readership current on POLMS.

Expression of the O-linked N-acetylglucosamine containing epitope H in normal myometrium and uterine smooth muscle cell tumors.

Epitope H contains an O-linked N-acetylglucosamine (O-GlcNAc) residue in a specific conformation and/or environment recognized by monoclonal antibody H (mAbH). We have previously shown that epitope H is present in more than one polypeptide and in various types of normal and pathological cells. In the present study, we focused on uterine smooth muscle cell tumors and their adjacent normal myometrium to gain further insight into the expression patterns of epitope H in human tissues. The indirect immunoperoxidase method was applied using the mAbH and the monoclonal anti-cytokeratin 8 antibody (AbCK8) in 50 cases of typical uterine leiomyomas and in five cases of uterine leiomyosarcomas, with four cases belonging to Group II A and one to Group III according to Bell et al. [6]. Western immunoblotting was applied using mAbH and AbCK8 in five cases of uterine leiomyomas and their adjacent myometrium. The main results were as follows: (1) epitope H showed intense immunohistochemical expression in 46% (23/50) and moderate expression in 54% (27/50) of uterine leiomyomas, (2) epitope H showed intense immunohistochemical expression in 40% (2/5) and moderate expression in 60% (3/5) of uterine leiomyosarcomas, (3) epitope H showed no difference in the immunohistochemical expression between leiomyomas and their adjacent myometrium and between leiomyosarcomas and their adjacent myometrium, (4) immunohistochemical expression of cytokeratin 8 was not detected in the normal and neoplastic smooth muscle cells, (5) Western immunoblotting showed that in the smooth muscle cells of the myometrium and leiomyomas, epitope H is localized in four polypeptides with molecular weights of 100, 61, 59, and 54 kDa, and (6) Western immunoblotting did not detect cytokeratin 8 in the normal and neoplastic smooth muscle cells. The present results indicate fluctuations of the epitope expression levels in uterine smooth muscle cell tumors and their adjacent myometrium. These fluctuations may be of interest for gaining insight into the pathogenesis of uterine smooth muscle cell tumors, since O-GlcNAc glycosylation is involved in cell cycle and apoptosis pathways and may modify proteins involved in oncogenesis (tumor suppressor proteins and oncoproteins) and proteins with important biological functions such as cytoskeletal proteins, transcription factors, and heat-shock proteins. Furthermore, the present results indicate that cytokeratin 8, without being present in the cells of the myometrium, leiomyomas and leiomyosarcomas, shares its epitope H, which contains its unique sugar O-N-acetylglucosamine residue, with four other unrelated polypeptides produced by the normal and neoplastic smooth muscle cells. This should be considered when using anti-cytokeratin 8 antibodies in immunohistochemistry against smooth muscle cell tumors to avoid false positive immunohistochemical results.

In vitro assay of spontaneous cytotoxicity by human monocytes and macrophages against tumor cells.

The [3H]proline microcytotoxicity technique has been adopted to examine the spontaneous cytotoxic property of human circulating monocytes (M) derived from the peripheral blood and resident monocytes/macrophages (M0) derived from effusion fluids. A leukocyte fraction is obtained by centrifugation in Ficoll-Hypaque (F-H) gradient. M are then isolated as adherent cells following incubation of the leukocyte fraction in plastic flasks containing 50% fetal calf serum (FCS) in culture medium. M0 are isolated from effusion fluids after first separating the Fc receptor bearing cells (as Fc receptor-7S EA resettes) in F-H gradient and then enriching them as adherent cells. The above techniques yield a M/M0 population of some 90-98% purity. The M/M0 non-selectively lyse tumor cells and allogeneic normal fibroblasts in the 48 h [3H]proline assay. The fibroblasts, however, exhibit considerable resistance to lysis, particularly at lower effector to target ratios. While appreciable levels of cytotoxicity are observed with resident M0 at 6 h, followed by a further increase in the level of cytotoxicity at 24-48 h, circulating M exhibit a consistent level of cytotoxicity only at 24-48 h. When circulating M and resident M0 from the same donor are examined concurrently for cytotoxicity, resident M0 are consistently found to show significantly higher levels of cytotoxicity when compared to circulating M. This may reflect a true functional heterogeneity within this lineage of effector cells or some degree of in vivo activation of resident M0 in malignant and non-malignant effusion fluids. Further studies of spontaneous cytotoxicity by M/M0 through CMC assay techniques, such as the [3H]proline microtoxicity technique, will be useful in the examination of the role of M/M0 in cell mediated immunity and immunosurveillance against cancer.

Leiomyosarcoma with prominent osteoclast-like giant cells. Analysis of eight cases closely mimicking the so-called giant cell variant of malignant fibrous histiocytoma.

Eight cases of leiomyosarcoma with osteoclast-like giant cells, arising in deep soft tissue, and that mimicked closely the "giant cell variant of malignant fibrous histiocytoma (MFH)," have been studied morphologically and immunohistochemically. The age of the patients ranged from 7 to 88 years (mean, 66.2 years; median, 74 years); five were female patients. Three lesions arose in the lower limbs, two in the buttock, and one each in the shoulder, chest wall, and the floor of the mouth. Follow-up in one case revealed a local recurrence and in two cases systemic metastases. All cases showed, at least focally, interwoven spindle cell fascicles, with the cytologic features of smooth muscle cells, as well as strong positivity for alpha-smooth-muscle actin, muscle actin, and desmin. The morphologically benign osteoclast-like giant cells expressed CD68 but failed to stain with myogenic markers. The association of leiomyosarcoma with prominent osteoclast-like giant cells is not as uncommon as generally believed, being evident in 8.7% of the deep-seated nonvisceral leiomyosarcomas that we have studied. These results provide good evidence for myogenic differentiation in at least a subset of those tumors with morphologic features currently classified as the giant cell variant of MFH. Considering that at least some other reported cases of giant cell MFH appear to be a variant of extraskeletal osteosarcoma, we would suggest that lesions with this distinctive pattern should be more carefully classified according to their apparent line of differentiation.

Smooth muscle tumors of the gastrointestinal tract. Flow cytometric quantitation of DNA and nuclear antigen content and correlation with histologic grade.

Simultaneous flow cytometric quantitation of DNA content and the proliferation-associated nuclear antigen p105 was performed on 41 gastrointestinal smooth muscle neoplasms and the results were correlated with histologic features. Aneuploid DNA stemlines were found in 17 cases (41%), including four of 15 (21%) tumors of unknown malignant potential, eight of 17 (47%) low-grade leiomyosarcomas, and five of seven (71%) high-grade leiomyosarcomas. In 10 of the 17 aneuploid tumors, an aneuploid peak was clearly identified on the single parameter DNA histogram, with a mean DNA index of 1.36. In the other seven aneuploid cases, a near-diploid, aneuploid population (mean DNA index, 1.08) was identified only by simultaneous immunofluorescence for p105. Clinical follow-up information was available for 14 patients. Mean survival of 10 patients with aneuploid tumors was 32 months, whereas mean survival of four patients with diploid tumors was 51 months. Of the seven patients who died within 1 year of diagnosis, six had aneuploid leiomyosarcomas. These findings demonstrate that DNA aneuploidy is common in high-grade gastrointestinal leiomyosarcomas and may be associated with shortened survival.

Epstein-Barr virus-associated leiomyosarcoma of the thyroid in a child with congenital immunodeficiency: a case report.

We report an unusual case of multifocal leiomyosarcoma involving the thyroid gland, liver, and right lung in a child with congenital immunodeficiency disease. The smooth muscle nature of these neoplasms was confirmed by immunohistochemistry and electron microscopic studies. In situ hybridization showed large amounts of Epstein-Barr virus messenger RNA within the tumor cells. Although Epstein-Barr virus-associated smooth muscle tumors have been reported in children with AIDS and after organ transplantation, we are unaware of any case report in congenital immunodeficiency disease.

Fatal tumor thrombosis due to an inferior vena cava leiomyosarcoma in a patient with antiphospholipid antibody syndrome.

We describe a patient with antiphospholipid antibody syndrome (APS) who died because of relentless inferior vena cava (IVC) tumor thrombosis due to an unsuspected leiomyosarcoma. Laboratory confirmation for APS was provided by functional identification of a lupus anticoagulant and anticardiolipin IgG and anti-beta2-glycoprotein I IgM antibodies. Although sensitive for detecting vascular obstruction, radiocontrast venography and magnetic resonance imaging and angiography detected the IVC thrombosis but failed to distinguish its malignant nature. Concomitant refractory thrombocytopenia prevented further invasive diagnostic and therapeutic maneuvers for progressive, severe IVC thrombosis unresponsive to aggressive treatment of APS. Deep venous thrombosis refractory to anticoagulant and immunomodulatory therapies in a patient with APS may be due to a concomitant underlying malignancy, such as a leiomyosarcoma, causing vascular obstruction.

Primary leiomyosarcoma of bone: report of eight cases.

Eight primary leiomyosarcomas of bone were registered in the files of the Basel Bone Tumor Reference Center, Basel, Switzerland, for the period 1972 to 1990. The mean age of the patients (six males and two females) was 43.7 years (range, 11 to 87 years). The tumors were located in the long bones, the fingers, and the clavicle, and presented radiologically mainly as slightly to moderately aggressive lesions (grades IB to II according to Lodwick). They reacted immunohistochemically with antibodies against alpha-smooth muscle actin (alpha-SMA), and total muscle actins (eight of eight), vimentin (seven of eight), desmin (three of eight), keratin (four of eight), type IV collagen (six of eight), laminin (five of eight), and S-100 (one of eight). Seven patients underwent surgery (five, resection; two, amputation). Some of them had received preoperative or adjuvant chemotherapy or radiation therapy. One patient with a metastasized tumor had received chemotherapy only. Tumor recurrences were observed in two cases. Four patients developed metastases of whom two were treated with chemotherapy or tumor resection. During a follow-up period of 1 to 72 months (mean, 46.5 months) four of the eight patients survived for up to 72 months, among them the only patient with grade 3 tumor and treated metastases.

Tissue polypeptide antigen expression in human prostate tumors.

Thirty-seven specimens of benign and malignant prostatic tumors were studied for the localization of tissue polypeptide antigen (TPA) by an avidin-biotin-peroxidase complex technique. In addition, 23 metastases of prostatic carcinoma in other organs and 12 nonepithelial tumors of prostate also were studied. All benign and malignant tumors of epithelial origin, including their metastasis, stained positively. Nonepithelial tumors were uniformly negative. In the metastatic lesions, small foci of tumor cells and even single tumor cells could be identified by TPA staining. Immunohistochemical localization of TPA appeared to be a useful tool for assessing the micrometastases of prostatic carcinoma in other organs, especially lymph nodes, or elucidating the epithelial origin of an otherwise undifferentiated prostatic cancer.

Immunofluorescence of soft-tissue tumors with anti-smooth-muscle and anti-skeletal-muscle antibodies.

One hundred thirteen soft-tissue tumors were studied by immunofluorescence using anti-smooth-muscle (SMA) and anti-skeletal-muscle antibodies (MGA). Of the classic leiomyomas examined, 94% manifested bright fluorescence with SMA, whereas cellular leiomyomas and leiomyosarcomas failed to stain. Of the rhabdomyosarcomas studied, 21% showed fluorescent cross-striations or fluorescent granules after incubation with MGA. None of 48 control tumors fluoresced with either antibody. No tumor vessel seen showed smooth-muscle fluorescence in its walls. Although of little diagnostic value, immunofluorescence utilizing specific human antibodies is a valuable tool with which to study some of the antigenic components of these neoplasms.