An osteoclast-rich tumor of the gastrointestinal tract with features resembling clear cell sarcoma of soft parts: reports of 6 cases of a GIST simulator

Six cases are reported of an osteoclast-rich tumor of the gastrointestinal tract that should be segregated from GIST. Five of the cases were located in the small bowel and one in the stomach. The age of the patients ranged from 13 to 37 years. The tumors behaved aggressively, with metastases to regional lymph nodes, liver, and other intra-abdominal sites. Microscopically, the tumor cells were medium-sized, predominantly oval, relatively monomorphic, diffusely immunoreactive for S-100-protein, and negative for CD117, CD34, HMB-45, and Mart-1. They were admixed with scattered osteoclast-like, multinucleated giant cells which were S-100-protein negative and KP1-positive. One case studied cytogenetically had the karyotype 46XX t(12;22)(q13;q12). The cases here reported are interpreted as examples of a distinctive type of gastrointestinal neoplasm which shares some features with clear cell sarcoma of soft parts (melanoma of soft parts), including in one case the chromosomal translocation that is characteristically associated with that entity.     

Clear cell sarcoma-like tumor with osteoclast-like giant cells in the small bowel: further evidence for a new tumor entity

Most mesenchymal neoplasms of the gastrointestinal tract belong to the category of gastrointestinal stromal tumors (GISTs) and are characterized by the immunohistochemical expression of KIT receptor. In cases without detectable KIT receptor expression several differential diagnoses have to be taken into consideration. Here, we report a case of a 41-year-old man with a tumor of the small bowel composed of large epithelioid tumor cells arranged in solid and alveolar sheets including scattered osteoclast-like multinucleated giant cells. Immunohistochemically, the tumor cells expressed strongly S-100 protein, vimentin, and to a lesser extent, bcl-2. HMB-45, melan-A, KIT receptor, desmin, smooth-muscle actin, and CD-34 were not detectable. Ki-67 index was 20%. The diagnosis was established by 2 different FISH strategies demostrating the presence of a t(12;22)(q13;q12) translocation, the diagnostic hallmark of clear cell sarcoma of soft parts. Our results provide further evidence for the existence of a new tumor entity designated gastrointestinal clear cell sarcoma with osteoclast-like giant cells. The diagnosis of this entity should be considered in the presence of S-100-positive tumors of the gastrointestinal tract containing multinucleated giant cells and can be established by FISH analysis.     

Intestinal clear cell sarcoma with melanocytic differentiation and EWS [corrected] rearrangement: report of a case

A clear cell sarcoma-like tumor with osteoclast-like giant cells of the gastrointestinal tract without immunoexpression of CD117 was recently proposed as a new tumor entity. In this article, a case of a 37-year-old man with a neoplasm of the jejunum composed of polygonal cells with clear to eosinophilic cytoplasm forming nests and fascicles is reported. Giant cells were not identified. Immunohistochemically, the tumor cells expressed strongly S100 protein, human melanoma black 45, platelet-derived growth factor receptor alpha, B-cell lymphoma 2, p53, and to a lesser extent vimentin, neuron-specific enolase, and epithelial membrane antigen. Mindbomb homolog-1 index was 35%. Immunoreactivity for CD34 and CD117 was negative. The fluorescence in situ hybridization analysis showed a translocation involving chromosome 22q12, the diagnostic hallmark of clear cell sarcoma of soft tissues. This case indicates a close histogenetic relationship with the recently reported clear cell sarcoma with osteoclast-like giant cells of the gastrointestinal tract, as well as with the clear cell sarcoma of soft tissues.     

Bronchogenic sarcomatoid squamous cell carcinoma with osteoclast-like giant cells

A 60-year-old man developed a widely metastatic spindle cell neoplasm with admixed osteoclast-like giant cells indistinguishable from malignant giant cell tumor of soft parts. Autopsy revealed a bronchogenic sarcomatoid squamous cell carcinoma that was the primary source of the sarcomatoid metastases. The osteoclast-like giant cells in the metastatic lesions were negative for lysozyme on immunoperoxidase staining. This finding suggested that the multinucleated giant cells were not formed as a cellular response to hemorrhage or to cellular debris induced by the tumor. Extraosseous neoplasms with osteoclast-like giant cells are rare neoplasms that may occur in a variety of organs. This case is the second reported case of a primary neoplasm in the lung that contained these osteoclast-like giant cells. These tumors may cause considerable diagnostic confusion.     

Malignant melanoma of soft parts: an ultrastructural study of four cases

Malignant melanomas of soft parts from 4 patients were studied by light microscopy, immunocytochemistry for S-100 protein, and electron microscopy. Each patient presented with a deep soft tissue mass in an extremity. Histologically, the tumors were composed of epithelioid and spindle cells, and in one, neoplastic giant cells were present. The tumors did not stain for melanin but were all positive for S-100 protein. Ultrastructurally, premelanosomes were identified in every tumor and in a cell line established from one tumor. Schwann cell features were present in one of the tumors. Although the clinical presentation of malignant melanoma of soft parts is similar to that of epithelioid sarcoma and synovial sarcoma, the combined light microscopic, immunocytochemical, and ultrastructural features should serve to distinguish it from other soft tissue sarcomas.     

伴破骨样巨细胞平滑肌肉瘤的临床病理学观察

目的 探讨伴破骨样巨细胞平滑肌肉瘤的临床病理学特点及其鉴别诊断.方法 收集7例伴大量破骨样巨细胞平滑肌肉瘤病例的临床和影像学资料,行光镜观察、免疫组织化学(EnVision法)标记和电镜观察,并复习相关文献.结果 患者均为成年人,其中女性3例,男性4例,平均年龄 63岁.肿瘤位于大腿皮下软组织2例,左背部、腹膜后、小肠、乳腺和子宫各1例.组织学上,所有病例均由形态相对一致、呈交织条束状排列的梭形瘤细胞和大量的破骨样巨细胞组成,后者多散在分布于梭形细胞之间(6例),或形成巨细胞瘤样结节(1例).免疫组织化学标记显示,梭形细胞程度不等地表达平滑肌肌动蛋白、肌特异性肌动蛋白、结蛋白和高相对分子质量钙调结合蛋白,破骨样巨细胞表达CD68.电镜观察显示梭形细胞具平滑肌分化特征,破骨样巨细胞则具组织细胞分化.随访6例患者,均在术后发生复发或转移,其中3例带瘤生存,2例死亡.结论 (1)伴大量破骨样巨细胞的平滑肌肉瘤是平滑肌肉瘤的一种少见亚型,形态上与巨细胞型恶性纤维组织细胞瘤相似,诊断时应注意加以鉴别.(2)免疫组织化学标记和电镜观察提示肿瘤内的破骨样巨细胞起源于单核细胞/组织细胞系.(3)该肿瘤的恶性程度高,预后差.

Abstract：

Objective To study the clinicopathologic features of leiomyosarcoma with prominent osteoclast-like giant cells. Methods The clinical and pathologic features of 7 cases of leiomyosarcoma with prominent osteoclast-like giant cells were analyzed. Immunohistochemical and ultrastructural studies were performed. The literature was reviewed. Results All cases occurred in adults, with a mean age of 63 years. There was no significant soft tissue of thigh (number=2), left back (number=1), retroperitoneum (number=1), small intestine (number=1), breast (number=1) and uterus (number=1). Histologic examination showed that the tumor was composed of relatively uniform spindly cells arranged in interlacing fascicles. The hallmark was the presence of prominent osteoclast-like giant cells, either intimately admixed with the spindly cells (number=6) or forming giant cell tumor-like nodules (number=1). Immunohistochemically, the spindly cells expressed smooth muscle actin, muscle-specific actin, desmin and h-caldesmon in various degrees, whereas the osteoclast-like giant cells expressed CD68. Ultrastructural study showed smooth muscle differentiation in the spindly cells and histiocytic differentiation in the osteoclast-like giant cells. Follow-up data were available in 6 cases. There were local recurrences and/or metastases in all the 6 patients. Three patients were alive with unresectable or recurrent/metastatic disease and two patients died of the disease. Conclusions Leiomyosarcoma with prominent osteoclast-like giant cells is a rare variant of leiomyosarcoma which should be distinguished from the so-called giant cell variant of malignant fibrous histiocytoma. The osteoclast-like giant cells are of histiocytic differentiation. Surgical resection remains the mainstay of management of this high-grade sarcoma.     

Clear cell sarcoma of the ileum: report of a case and review of literature

Clear cell sarcoma (CCS) is a high grade soft tissue sarcoma with a distinct molecular profile and with morphological features resembling those of melanoma. CCS has been rarely described in other locations other than the soft tissues, including the gastrointestinal tract. In this study, we report a case of CCS arising in the ileum of a 31-year-old woman. Histologically, the tumor involved the entire thickness of the intestinal wall. Tumor cells were polygonal or fusiform, with clear or eosinophilic cytoplasm, arranged in a uniform nested to fascicular growth pattern. Immunohistochemical studies revealed strong positivity for vimentin and S-100 protein. HMB-45, Melan-A, tyrosinase, cytokeratins, EMA, smooth muscle actin, CD34, CD31, CD117, CD99, synaptophysin, chromogranin A, CD56, and NSE were negative. Fluorescence in situ hybridization analysis demonstrated the presence of a t(12;22)(q13;q12) translocation, the diagnostic hallmark of CCS of soft parts. The present case, together with a detailed review of the literature on this topic, demonstrates that the gastrointestinal tract is a possible site of CCS of soft tissues and that making a reliable diagnosis of this tumor requires cytogenetic or molecular diagnostic investigations.     

Giant cell tumor of the skin: a morphologic and immunohistochemical study of five cases

Giant cell tumor (GCT) of the skin is a rare entity that possesses similar gross and histologic features to GCT of bone. When located predominantly in the dermis GCT has been mistaken for benign fibrous histiocytoma and atypical fibroxanthoma. We report the clinical, morphologic, and immunohistochemical features of five cases of GCT of the skin. With one exception, all tumors are confined to the dermis. Patients' ages range from 6 to 78 years (median, 73 years) with a male to female ratio of 3:2. Gross and histologic features of the lesions are similar to those of GCT of bone (eg, brown fleshy tumor and a biphasic population of mononuclear cells admixed with osteoclast-like giant cells, respectively). The nuclei of the giant cells are similar to those of the mononuclear cells. A fascicular pattern with focal storiform arrangement of spindle neoplastic cells is noted in two cases. The osteoclast-like giant cells and some of the mononuclear cells are strongly positive for CD68, alpha-1-antitrypsin, and alpha-1-antichymotrypsin. Only the mononuclear cells express smooth muscle actin focally in one case. Both the osteoclast-like giant cells and the mononuclear cells are negative for cytokeratins (AE1/AE3 and CAM5.2) and S-100 protein in all cases. One patient developed lung metastases at presentation and local recurrence 4 months status post surgery. All patients are without evidence of disease 1 month to 12 years status post surgery. Cutaneous GCTs are low-grade sarcomas that can recur locally and infrequently metastasize. These tumors should be distinguished from a variety of cutaneous neoplasms that contain multinucleated giant cells.     

Invasive mammary carcinoma with osteoclast-like giant cells diagnosed by fine-needle aspiration biopsy: review of the cytologic literature and distinction from other mammary lesions containing giant cells

Invasive carcinoma with osteoclast-like giant cells is an unusual type of mammary adenocarcinoma with few cases reported in the cytology literature. We present the cytologic findings in a case of invasive cribriform carcinoma of the breast containing osteoclast-like giant cells diagnosed by fine-needle aspiration biopsy. The smears displayed three-dimensional cohesive cluster cells of uniform epithelial cells admixed with numerous multinucleated giant cells that morphologically resembled osteoclasts. Core biopsy confirmed the cytologic diagnosis. Immunohistochemical studies indicated that the multinucleated giant cells were of histocytic origin. Knowledge of the bland cytologic pattern and the admixture of giant cells seen in invasive cribriform carcinoma with osteoclast-like giant cells should avoid making a false negative diagnosis on aspiration biopsy.     

Primary malignant neuroectodermal tumor of the ileum with predominantly uncommon pseudopapillary architecture

A malignant gastrointestinal neuroectodermal tumor (GNET), a distinctive entity covering the characteristics of clear cell sarcoma (CCS) of gastrointestinal tract described recently, arising primarily in the ileum of a 33-year-old woman is reported. Histologically, the neoplasm involved the full thickness of the intestinal wall. Tumor cells, mainly displayed epithelioid or polygonal appearance with oval or round nuclei, arranged in strand, nested, and solid pattern with prominent pseudopapillary architecture instead of the familiar histological image with multinucleated osteoclast-like giant cells. They were positive for vimentin, S-100, synaptophysin, CD56 and CD99 protein, but negative for AE1/AE3, EMA, CEA, LCA, Desmin, CK7, CK20, Villin, CgA, CD117, Dog-1, GFAP, Melan-A, HMB-45, CD34, CR, WT1, D2-40. Fluorescence in situ hybridization (FISH) showed the presence of chromosomal translocation involving EWSR. The patients lived through a calm period after a tumor resection and 4 cycles of chemotherapy combining ifosfamide and epirubicin. This case demonstrates that GNET is a rare tumor in gastrointestinal tract, and furthermore, various misleading histological characteristics should been taken into consideration in the diagnosis.     

Malignant diffuse-type tenosynovial giant cell tumor of the buttock

Malignant diffuse-type tenosynovial giant cell tumor (D-TSGCT) is an unusual sarcoma. We report a case of malignant D-TSGCT located in the left buttock. A 58-year old woman noticed a small mass at her left buttock 3 months previously. The mass tended to enlarge rapidly, and became 6 cm in diameter. Tumor resection was performed. Grossly, the tumor showed a solid growth pattern and whitish appearance with hemorrhage and necrosis. Microscopically, the tumor was composed of a proliferation of short spindle and oval mononucleated cells with numerous osteoclast-like multinucleated giant cells, which occasionally showed coagulative necrosis. In addition, tumor cells had high mitotic activity and atypical mitoses. Immunohistochemically, the mononucleated cells were positive for CD163 and focally positive for CD68 (clone KP-1 and PG-M1), CD4, smooth muscle actin and S100 protein. Osteoclast-like multinucleated giant cells were positive for CD68 (clone KP-1 and PG-M1) and CD4. Pulmonary metastases were found 6 months after the operation. These findings indicate that this lesion is consistent with malignant D-TSGCT.     

Benign intradermal melanocytic naevus with osteoclast-like giant melanocytes: a case report of an unusual morphological pattern

Multinucleated osteoclast-like melanocytes are a relatively common feature in malignant melanoma, however reported cases of benign melanocytic naevi with giant cells melanocytes are scarce. Herein, we present an unusual case of an intradermal melanocytic naevus with numerous benign giant cell melanocytes. A 42-year-old female presented with a small papule on the forehead which was excised. Histologically, the lesion was formed of an intradermal proliferation of benign melanocytes without junctional activity. The melanocytes were arranged in small nests and showed neither cytological atypia nor mitotic activity. There were numerous multinucleated osteoclast-like giant cells with abundant eosinophilic granular cytoplasm and several small open face nuclei. These multinucleated cells showed immune reactivity to melanocytic markers. This case represents a rarely described morphological pattern of a benign intradermal melanocytic lesion showing multiple benign giant cell melanocytes. Reporting such a case provides further evidence to support the presence of this morphological entity and would aid in further understanding its biology and clinical significance.     

Epithelioid leiomyosarcoma with osteoclast-like giant cells in the rectum

We report a rare case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells. A 71-year-old Japanese man was admitted to a hospital with melena. Results of a colonoscopy test revealed a polypoid tumor in the rectum, and a biopsy specimen from the lesion showed a sarcoma; the patient underwent rectosigmoidectomy. At gross inspection, the tumor measured 8 x 7 x 4 cm and was polypoid with ulcerations. Necrotic and hemorrhagic foci were scattered. Microscopically, the tumor consisted of 2 cell types: malignant tumor cells with epithelioid features and benign-appearing osteoclast-like giant cells. The tumor cells were polygonal and epithelioid in shape and had eosinophilic or clear cytoplasms, with scattered giant tumor cells. Immunohistochemical examination revealed that the tumor cells were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin, whereas the osteoclast-like giant cells were positive for CD68, leukocyte common antigen, and lysozymes. We diagnosed this case as epithelioid leiomyosarcoma with osteoclast-like giant cells. To the best of our knowledge, this is the first case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells.     

HLA-DR (Ia-like) reactivity in tumors of bone and soft tissue: an immunohistochemical comparison of monoclonal antibodies LN3 and LK8D3 in routinely processed specimens.

Recent studies of Class II histocompatibility antigen expression in bone and soft tissue sarcomas have suggested that malignant fibrous histiocytoma (MFH) may express HLA-DR, whereas histologically similar pleomorphic, epithelioid, and spindle cell malignant neoplasms generally do not. To test whether these observations are reproducible in the differential diagnosis of soft tissue sarcomas, anti-HLA-DR antibodies LK8D3 and LN3 were applied to formalin-fixed, paraffin-embedded sections of MFH, neurofibrosarcoma (NFS), leiomyosarcoma (LMS), synovial sarcoma (SS), fibrosarcoma (FS), angiosarcoma (AS), Kaposi's sarcoma (KS), chondrosarcoma (ChS), "dedifferentiated" chondrosarcoma (DChS), osteosarcoma (OS), epithelioid sarcoma (ES), and clear cell sarcoma (CCS; malignant melanoma of soft parts). The only consistent difference in Class II antigen expression was seen in the group of neoplasms composed of large polygonal cells. Among the latter lesions, four of six clear cell sarcomas were labeled by LK8D3 or LN3, but none of 12 epithelioid sarcomas were reactive. Otherwise, a diversity of tumors in other morphologic categories expressed Class II antigens, with no clear diagnostic patterns. These results may be of use in the diagnostic separation of large cell epithelioid tumors of soft tissue, but neither LN3 nor LK8D3 appears to be helpful in the identification of other sarcomas.     

Malignant mesenchymomas of soft tissue associated with numerous osteoclast-like giant cells mimicking the so-called giant cell variant of “malignant fibrous histiocytoma”

Three cases of malignant mesenchymoma with numerous osteoclast-like giant cells, arising in deep soft tissue, and which mimicked the so-called giant cell variant of malignant fibrous histiocytoma have been studied. All three neoplasms arose in adults; two patients were male and one was female. Two tumours arose in the thigh, and one in the right shoulder. Two patients died within 2 years of the primary excision while the third is alive and well at 2.5 years. Histologically, one case showed leiomyosarcoma plus liposarcoma, one leiomyosarcoma plus osteosarcoma, and one tumour consisted of liposarcoma plus osteosarcoma; all components were assessed morphologically as high-grade malignant. All three cases showed prominent osteoclast-like giant cells in the leiomyosarcomatous or osteosarcomatous areas, thereby closely mimicking the phenotype of so-called giant cell variant of malignant fibrous histiocytoma. We discuss briefly differences in soft tissue sarcomas demonstrating this distinctive osteoclast-rich phenotype.     

Similarities between giant cell tumor of bone, giant cell tumor of tendon sheath, and pigmented villonodular synovitis concerning ultrastructural cytochemical features of multinucleated giant cells and mononuclear stromal cells

The authors investigated ultrastructural cytochemical features of multinucleated and mononuclear stromal cells in giant cell tumor of bone (GCTB), giant cell tumor of tendon sheath (GCTTS), and pigmented villonodular synovitis (PVNS). Specimens of each tumor, respectively numbering 4, 4, and 3, were stained for tartrate-resistant acid phosphatase (TRAP) reactions and examined with an electron microscope. In GCTB and GCTTS, multinucleated cells, including some relatively small giant cells, showed TRAP activity and cytoplasmic features characteristic of osteoclasts, and also sometimes abundant rough endoplasmic reticulum and siderosomes. A few giant cells with macrophage-like features and slight TRAP activity were demonstrated in GCCTS and PVNS. In each tumor type, mononuclear cells showing TRAP activity shared cytoplasmic features with osteoclast-like multinucleated giant cells, while some others had macrophage-like features, and still others were poorly differentiated; a few mononuclear cells showed cell-to-cell contact. Ultrastructural similarities of TRAP-positive mononuclear cells in the three tumor types, and those between TRAP-positive multinucleated cells in GCTB and GCTTS, suggest a common cell lineage capable of multinucleated giant cell formation in the 3 tumors, despite differing histogenesis.     

Giant cell fibroblastoma. A case report

A case of giant cell fibroblastoma occurring in the knee of a 16-month-old girl is reported. The ill-defined subcutaneous tumor measuring 2 x 2 cm was composed of diffusely proliferating spindle-shaped tumor cells with scattered, atypical multinucleated giant cells in a myxoid or collagenous background and irregularly branching sinusoid-like tissue spaces. In addition to floret-type giant cells, a few osteoclast-like giant cells were present in a cellular area where tumor cells were focally arranged in a storiform pattern. Immunohistochemically, the tumor cells gave positive reactions for only vimentin and actin. In spite of the high recurrence rate of this type of tumor, the course of the patient after excision of the tumor has been uneventful. It is important to distinguish this rare, peculiar fibrous tumor from other soft tissue tumors including some sarcomas.     

ANAPLASTIC CARCINOMA OF THE THYROID WITH OSTEOCLAST-LIKE GIANT CELLS

An unusual anaplastic thyroid carcinoma with osteoclast-like giant cells is reported in a 72-year-old woman. Monotonous proliferation of variously sized mononuclear tumor cells interspersed with numerous osteoclast-like multinucleated giant cells was dominant. A small area of papillary carcinoma merging with the anaplastic carcinoma was disclosed. Immunohistochemically, tumor cells forming papillary pattern were positive for both thyroglobulin and keratin. Cells and cell clusters positive for keratin were found in anaplastic carcinoma. Electron microscopically, the anaplastic carcinoma cells displayed prominent mitochondria, a rough endoplasmic reticulum, and intermediate cell junctions. The cell clusters formed irregular lumina into which numerous microvilli were extended and which contained colloid-like material. Occasionally incomplete basal laminae were present. Cell clusters showing transitional pictures from cell clusters to multinucleated giant cells and multinucleated giant cells engulfing mononuclear tumor cells were observed by both light and electron microscopy. Findings from this study support the conclusion that anaplastic tumor cells arise in preexisting differentiated thyroid cancer and that associated multinucleated giant cells are formed by the fusion of carcinoma cells.     

Epithelioid hemangioendothelioma with osteoclast-like giant cells

Epithelioid hemangioendothelioma is an unusual entity of intermediate malignant vascular tumors and rarely admixes with multinucleated osteoclast-like giant cells. We describe such a case in a 50-year-old woman with an 1-year follow-up period. When the patient was 39 years old, a 0.7 x 1-cm firm mass was found in the left neck. She developed ascites three years later. At that time, the specimen from the neck mass was excised and found to be composed of cords of epithelioid cells in a myxoid hyaline stroma. Scattered intracytoplasmic vacuoles were seen. Immunohistochemical studies confirmed the diagnosis of epithelioid hemangioendothelioma. Abdominal ultrasonography and computed tomographic scan revealed multiple low density areas in the liver. Eleven years later, a metastatic lesion was found in the thoracic spine at the level of Th7-8. The histologic findings were basically similar to those of the left neck mass. However, because of the presence of Kp-1-positive multinucleated osteoclast-like giant cells throughout the tumor, the thoracic lesion was diagnosed as an epithelioid hemangiothelioma with osteoclast-like giant cells. This unique form of epithelioid hemangioendothelioma is extremely rare and should be distinguished from other benign and malignant tumors with osteoclast-like giant cells.