Spindle-cell sarcomas

Fig. 8. Study of a patient (with spindle cell sarcoma) given adenine-8- C (200 lc) 3 weeks prior to 2-ethylamino-l,3,4-thiadiazole (TDA). The thiadiazole was given at a time when the decay curve of urine uric acid- C was a straight line. Note the sharp drop in concentration in urine uric acid produced by the thiadiazole. Ammonium chloride- N was incorporated to a much greater extent when given during thiadiazole administration than during the control study. The second N curve has been corrected here for the extrapolated value of the first curve. [From (K18).]...

FIGURE 3.2 Lymph node biopsy from a patient with Kaposi s sarcoma. The spindle cells show strong nuclear staining for HHV-8 LANA-1 antigen. Endothelial cells of well formed vascular spaces are negative. (Immunoperoxidase staining with DAB and hematoxylin counterstain x400.)... 

KER, keratin, detected by a mixture of GAMS.2, MAK-6, and AEl /AE3 EMA, epithelial membrane antigen VIM, vimentin DES, desmin MSA, muscle-specific actin SMA, smooth muscle (alpha isoform) actin GALD, h-caldesmon S-IOOP, S-100 protein OCN, osteocalcin LM, laminin UL, Ulex europaeus I lectin binding FS, fibrosarcoma SGRMS, spindle cell rhabdomyosarcoma LMS, leiomyosarcoma MPNST, malignant peripheral nerve sheath tumor MSS, monophasic spindle cell synovial sarcoma SCAS, spindle cell angiosarcoma KS, Kaposi s sarcoma FOS, fibroblastic osteosarcoma. 

The BCL-2 (B-cell lymphoma-2) proteins are anti-apoptotic polypeptides that are differentially expressed in some soft tissue lesions. Those that commonly label immunohistologically include solitary fibrous tumor, spindle-cell lipoma, Kaposi s sarcoma, and monophasic... 

The spindle cell sarcomas of the deep soft tissues (Fig. 

Leiomyosarcomas are most commonly found in the retroperitoneum in adults. They uncommonly occur in the deep soft tissues of the extremities but may be seen in more superficial sites, particularly in the dermis and subcutis. The differential diagnosis of LMS traditionally includes other sarcomas composed of intersecting spindle-cell fascicles, including fibrosarcoma, MPNST, synovial sarcoma, and spindle cell rhabdomyosarcoma. Additional conditions such as IMT (inflammatory pseudotumor), neurofibroma, and hemangiopericytoma (see Fig. 4.5) are also considerations. 

Another spindle cell tumor that shares immunophe-notypic features with MPNST is monophasic synovial sarcoma (MSS). Roughly 40% of cases of MSS show SlOO staining, and approximately 30% are CD57-positive. " Cytokeratin subset analysis may be useful in difficult cases, because most synovial sarcomas are reactive for CK7 or CK19, or both. " In contrast, MPNSTs typically lack those proteins. CD 10-reactivity also favors a diagnosis of MPNST, whereas TLEl-positivity typifies MSS. 

Monophasic spindle cell (so-called fibrous) synovial sarcomas represent one extreme of the morphologic spectrum of those neoplasms. Classic biphasic synovial... 

The presence of EMA is typically observed in MSS (Fig. 4.18). Unlike its biphasic variant, spindle cell synovial sarcoma is only locally and inconsistently reactive for cytokeratin in particular, it may show reactivity for CK7, CK8, CK18, and CK19.396 42i Although car-cinoembryonic antigen may occasionally be found in the epithelial components of biphasic synovial sarcomas, it is absent in spindle cells in all cases.However, collagen type IV and E-cadherin may be diffusely expressed in MSS. - ... 

Given the many clinicopathologic similarities between EPS (especially its proximal variant) and the very rare purely epithelioid synovial sarcoma, it would follow that they are difficult to separate by immunophenotypic analysis. A helpful discriminant between these neoplasms is CD34, which is present in EPS but not in epithelioid synovial sarcoma. Moreover, as cited above, Kato and associates found that nearly all EPS cases were immunoreactive for CA125, whereas synovial sarcomas lacked that marker. As mentioned earlier in this discussion, monophasic spindle-cell synovial sarcoma is consistently reactive for nuclear TLEl protein however, that moiety has not been studied specifically in the monophasic epithelioid variant. 

Clear cell sarcoma (CCS) was formerly thought to represent a primary soft tissue counterpart of cutaneous malignant melanoma. Nonetheless, it is now known that CCS exhibits a consistent and characteristic t(12 22) chromosomal translocation that is not shared by mela-nocytic lesions of the skin. This neoplasm is typified by an epithelioid and/or spindle cell constituency, with a delicate fibrovascular stroma and clear or lightly eosinophilic cytoplasm. Melanin pigmentation may or may not be observed. 

Giangaspero E, Eratamico EC, Ceccarelli C, et al. Malignant peripheral nerve sheath tumors and spindle cell sarcomas An immunohistochemical analysis of multiple markers. Appl Pathol. 1989 7 134-144. 

Swanson PE, Manivel JC, Wick MR. Immunoreactivity for Leu7 in neurofibrosarcoma and other spindle cell sarcomas of soft tissue. Am J Pathol. 1987 126 546-560. 

Renshaw AA. 013 (CD99) in spindle cell tumors Reactivity with hemangiopericytoma, solitary fibrous tumor, synovial sarcoma, and meningioma, but rarely with sarcomatoid mesothelioma. Appl Immunohistochem. 1995 3 250-256. 

Nakanishi I, Katsuda S, Ooi A, et al. Diagnostic aspects of spindle-cell sarcomas by electron microscopy. Acta Pathol Jpn. 1983 33 425-437. 

Clear cell sarcoma (melanoma of soft parts) Young adults. Deep soft tissue with nodal and lung metastases. Mixed epithelioid and spindle cells in nested growth pattern S100+, HMB45+, melanA+ RT-PCR for EWS-ATF1 (not seen in cutaneous melanoma)... 

Miettinen M. Keratin subsets in spindle cell sarcomas. Keratins are widespread but synovial sarcoma contains a distinctive keratin polypeptide pattern and desmoplakins. Am Pathol. 1991 138 505-513. 

MMs are invariably positive for vimentin, which may be a pitfall in dealing with amelanotic spindle cell MMs. As a general rule, in diagnosing a spindle cell lesion of the sinonasal tract one must consider MM, spindle cell carcinoma, and a malignant myoepithelioma before soft tissue sarcomas. Rare MMs may also be focally positive for CAM 5.2 and EMA, which poses a problem when dealing with an epithelioid MM. 

KER, keratin (mixture of monoclonal antibodies) EMA, epithelial membrane antigen VIM, vimentin CALRET, calretinin DES, desmin MSA, muscle-specific actin AFP, alpha fetoprotein SYN, synaptophysin CCA, chromogranin A MESOTH, mesothelioma SCYST, spindle cell yolk sac tumor LMS, leiomyosarcoma SPCCA, spindle cell carcinoma (either primary or metastatic) SYNSC, synovial sarcoma SPCNC, spindle cell neuroendocrine carcinoma FS, fibrosarcoma MFH, malignant fibrous histiocytoma. 

Attanoos and associates evaluated 31 sarcomatoid mesotheliomas and a spectrum of other spindle cell neoplasms with antibodies directed against cytokeratin, thrombomodulin, calretinin, and CK5/6. Twenty-four of 31 (77%) sarcomatoid mesotheliomas expressed cytokeratin, 9 of 31 (29%) expressed thrombomodulin, 12 of 31 (39%) expressed calretinin, and 9 of 31 (29%) expressed CK5/6. Two of 9 (22%) sarcomas not otherwise specified expressed broad-spectrum cytokeratin and thrombomodulin, and 1 of 9 (11%) expressed CK5/6. As might be expected, 100% of synovial sarcomas expressed broad-spectrum keratin but showed no immu-nostaining for thrombomodulin, calretinin, and CK5/6. Two of 3 (67%) angiosarcomas expressed thrombomodulin, which is not surprising since thrombomodulin... 

Carter D, Otis CN. Three types of spindle cell tumors of pleura Fibroma, sarcoma and sarcomatoid mesothelioma. Am J Surg Pathol. 1988 12 747-753. 

Ewing s sarcoma/ PNET SRCs in sheets with round nuclei, fine chromatin, scanty cytoplasm. Variable rosettes, prominent nucleoli, spindle cells, necrosis. Vimentin, CD99, synaptophysin, Fli-1. t(11 22)(q24 q12)with EWS/FLI-1 fusion. t(21 22)(q22 q12)with EWS/ERC fusion. t(7 22)(p22 q12) with EW5/ETV1 fusion. t(17 22)(q12 q12) with EWS/E1AF fusion. t(2 22)(q33 q12)with EWS/ ffVfusion. Other translocations. 

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