An unusual leiomyosarcoma of the uterus containing osteoclast-like giant cells

Uterine Leiomyosarcoma With Osteoclast-like Giant Cells: Report of 2 Cases and Review of Literature

Leiomyosarcoma (LMS) with osteoclast-like giant cells (OLGCs) is a rare entity with only 18 reported cases thus far. It is not known whether these OLGCs are a reactive or malignant component of LMS. Herein we describe the clinical, histologic, and molecular characteristics of 2 cases of LMS with OLGCs and perform a brief literature review. In 2 of our cases, the OLGCs, marked with CD68, had a low proliferation index with Ki67 and did not show diffuse positivity for smooth muscle markers by immunohistochemistry. By next-generation sequencing, one case harbored a clinically significant TP53 mutation, which has been reported in a significant subset of conventional LMSs. In this case, based on immunohistochemistry, OLGCs showed different molecular alterations as compared with LMS. Although we did not show a distinct immunophenotype or molecular profile for LMS with OLGCs, this study provides additional data on this rare entity.

Uterine leiomyosarcomas with osteoclast-like giant cells associated with high expression of RUNX2 and RANKL

Uterine leiomyosarcoma (ULMS) with osteoclast-like giant cells (OLGCs) has been reported as a rare phenomenon in ULMS, and its clinico-pathological features and tumorigenesis remain unclear. We recently reported high expression of receptor activator of nuclear factor κB ligand (RANKL) in ULMS with OLGCs. As osteoblasts produce RANKL, in this study, we analyzed the expression of Runt-related transcription factor 2 (RUNX2), a critical transcription factor for osteoblasts, and osteoclast-related proteins in three cases of ULMS with OLGCs as well as five conventional ULMSs and nine leiomyomas. Immunohistochemistry and real-time reverse transcription quantitative polymerase chain reaction analyses showed high expression of RUNX2 and RANKL in ULMS with OLGCs. In these cases, macrophages expressed receptor activator of nuclear factor κB (RANK), and OLGCs expressed osteoclast-related proteins (nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), and cathepsin K). Accumulation sites of cathepsin K-positive OLGCs showed hemorrhagic appearance and degraded type IV collagen. We reviewed reported cases of ULMS with OLGCs, including ours, and found that they presented an aggressive course even at stage I. Furthermore, metastatic lesions showed similar histological features to those of OLGC association in ULMS. Here, we show that tumor cells in ULMS with OLGCs highly express RUNX2 and RANKL and that osteoclastic differentiation of macrophages occurs in the tumor tissue.

Leiomyosarcoma with osteoclast-like (LMS-OGC) giant cells the breast: A report of a rare case

Leiomyosarcoma with osteoclast‐like giant cells (LMS‐OGC) has seldom been reported clinically. LMS‐OGC of the breast is extremely rare according to the literature. Here, we report a case of LMS‐OGC leiomyosarcoma with osteoclast‐like giant cells of the breast. A 51‐year‐old female patient presented with a breast mass which was treated surgically and the pathological examination of the tumor indicated LMS‐OGC. Microscopically, the tumor was composed of spindle cells arranged in bundles or spokes with giant tumor cells and mitosis. Eosinophilic cytoplasm and morphologically benign osteoclast‐like cells were mixed together. Immunohistochemistry examination revealed SMA and desmin were positive with a Ki‐67 proliferation index of 40%. However, CK (AE1/AE3), E‐cadherin, ER, PR, CD34, S‐100 and CD10 were negatively expressed in the tumor tissue. LMS‐OGC is a soft tissue malignant tumor which develops extremely rarely in the breast. It should be differentiated and diagnosed according to the history, histological characteristics and immunohistochemical staining.

Urinary bladder leiomyosarcoma with osteoclast-like multinucleated giant cells: a case report

Background

Bladder leiomyosarcoma is the most frequent mesenchymal neoplasm of the bladder. However, the rarity of the disease and some morphological aspects could give serious problems to differential diagnosis.

Case presentation

A 86-year-old male patient was referred to our institution to undergo endoscopic low-urinary-tract re-evaluation 2 months after the detection of a “low-grade urothelial neoplasia” in urinary cytology. A TURBT (transurethral resection of bladder tumor) was performed and revealed a tumor extending for 3.5 cm with thin stalk peduncle on the left lateral wall of the bladder, cephalad and lateral to the left ureteral orifice. The exophytic part of the tumor was resected with the underlying bladder wall. Histologically, the tumor showed a quite complex pattern, composed of spindle cells, with often invasion to the surrounding bladder muscular wall, and the presence of numerous multinucleated, osteoclast-like giant cells, scattered throughout the neoplasia.

Conclusions

Here we report a unique case of urinary bladder leiomyosarcoma with osteoclast-like multinucleated giant cells (OGCs). These cells, confounding the morphological aspect, indeed showed an immunohistochemical phenotype of non-neoplastic origin (most likely a histiocyte/macrophage differentiation). We feel that the presence of the OGCs within this tumor is reactive. Nevertheless, more research is necessary to understand the role of OGCs in urinary bladder tumors and leiomyosarcoma, in paticular.

Uterine pleomorphic leiomyosarcoma with osteoclastic giant cells: Case report with peritoneal washing cytology and cell block study

Uterine leiomyosarcoma (LMS) with osteoclastic giant cells (OGCs) is extremely rare. However, its morphological appearance and aggressive behavior may have resulted in its being diagnosed as so-called giant cell malignant fibrous histiocytoma (MFH) in the past. Effusions are not uncommon in LMS and may be indicative of an unfavorable prognosis. We report a case with the cytological appearance of a uterine LMS with OGCs metastatic to lower pelvic peritoneum. The pelvic washing specimen consisted of three-dimensional aggregates of atypical cells. The cytohistologic and immunohistochemical study obtained from the cell block and the tumor mass showed overlapping features such as bizarre pleomorphic spindle cells containing numerous evenly dispersed OGCs. The malignant tumor cells showed extensive positivity for desmin, h-caldesmon and multifocal positivity for smooth muscle actin (SMA) whereas OGCs stained with CD68. We stress the usefulness of performing cell block and subsequent immunohistochemistry in order to make an accurate cytohistologic correlation.

Myxoid Leiomyosarcoma of the Uterus -A Case Report with Light Microscopic and Ultrastructural Appraisal

A case of an infiltrating myxopolypoid tumor of the uterus is presented. Histologically, the tumor revealed spindle-shaped cells with mitotic counts ranging between 1-4/hpf, myxoid stroma, and multinucleated giant cells mimicking syncitial giant cells of pregnancy trophoblast. Conventional light microscopic methods failed to establish the histogenesis of the tumor. At the ultrastructural level the tumor showed three main cellular components; myoblasts, myofibroblasts and collagen-producing fibroblasts. On the basis of light microscopic and electron microscopic findings, the tumor was labelled myxoid leiomyosarcoma. This variant of leiomyosarcoma is rare. This is the seventh case reported in the international literature.

Giant Cell Tumor of the Uterus: A Report of 3 Cases With a Spectrum of Morphologic Features

Giant cell tumors, a well-recognized neoplasm of bone, can rarely be found in the uterus. Such tumors are characterized by a dual population of mononuclear and osteoclast-like giant cells that lack epithelial and specific mesenchymal differentiation. In this study, the clinicopathologic features of 3 giant cell tumors of the uterus were reviewed. Immunohistochemistry for CD68, CD163, h-caldesmon, desmin, SMA, AE1/AE3, CD10, ER, PR, cyclin D1, CD1a, CD34, CD30, S100, myogenin/myoglobin, and Ki-67 was performed in all tumors, along with ultrastructural analysis in one. The patients were 47, 57, and 59 yr and the tumors measured 2.5, 7.5, and 16.0 cm. One neoplasm was confined to the endometrium, whereas the other 2 were myometrial. All 3 tumors showed a nodular growth comprised of mononuclear and osteoclast-like giant cells. The endometrial-confined tumor consisted of histologically benign mononuclear cells, whereas the others exhibited marked atypia. Mitotic activity was up to 5/10 HPF in the benign tumor and up to 22/10 HPF in the malignant. No cytologic atypia or mitoses were observed in the giant cells. CD68 and CD10 were strongly and diffusely expressed in both components of 3 and 2 neoplasms, respectively. Cyclin D1 was focal in the mononuclear cells and focal to diffuse in the giant cells. CD163 was diffuse in the mononuclear cells, but absent to focal in the giant cells. Ultrastructural analysis lacked diagnostic features of epithelial or specific mesenchymal differentiation. Both malignant tumors demonstrated an aggressive behavior. In summary, although rare, giant cell tumor of the uterus should be included in the differential diagnosis of benign or malignant tumors containing osteoclast-like giant cells.

Uterine Leiomyoma With Osteoclast-like Giant Cells

Numerous histologic variants of uterine leiomyomas have been described. The main interest in recognizing these variants is differentiating them from leiomyosarcoma. Osteoclast-like giant cells (OLGC) have been described in association with leiomyosarcoma but to our knowledge, never with leiomyoma. We here report the case of a 58-year-old woman who underwent an elective total hysterectomy with bilateral salpingo-oophorectomy and bilateral pelvic lymphadenectomy for endometrial atypical complex hyperplasia. Multiple typical uterine leiomyoma were identified. One of them showed numerous OLGC admixed with fascicules of bland smooth muscle cells. No atypical features were identified in multiple sections of this otherwise classic uterine leiomyoma. The OLGC showed strong positivity for CD68. The patient, on follow-up, did not show any evidence of recurrent or metastatic disease. This unusual finding expands the morphologic spectrum of uterine leiomyomas. When confronted with a uterine smooth muscle cell tumor with an OLGC component, it is important to search for atypical features diagnostic of leiomyosarcoma.

Uterine leiomyosarcoma with osteoclast-like giant cells associated with high expression of receptor activator of nuclear factor κB ligand

The occurrence of osteoclast-like giant cells (OLGCs) in uterine leiomyosarcomas (LMSs) is a rare phenomenon. The nature of OLGCs and the significance of their accumulation in these tumors are poorly understood. Recent studies revealed that the formation of osteoclasts requires a specific cytokine, receptor activator of nuclear factor κB ligand (RANKL), in bone. In this study, we investigated the expression of RANKL in 2 cases of uterine LMS with OLGCs by means of immunohistochemistry and compared the extent of RANKL expression with that in conventional uterine LMSs and leiomyomas by using real-time reverse-transcription quantitative polymerase chain reaction. Our cases of uterine LMS with OLGCs showed markedly high expression of RANKL messenger RNA with clear RANKL immunoreactivity compared with messenger RNA expression and immunoreactivity of conventional uterine LMSs and leiomyomas. These findings suggest that the tumors producing RANKL may account for accumulation of OLGCs in tumor tissue because of RANKL-related osteoclastogenesis.

A uterine leiomyoma in which a leiomyosarcoma with osteoclast-like giant cells and a metastasis of a ductal breast carcinoma are present

Leiomyosarcoma of the uterus is a rare tumor, and the presence of osteoclast-like giant cells in this tumor is even rarer. A leiomyosarcoma arising in a leiomyoma is also quite unique. Breast cancer metastasizing to the uterus is seldom seen as well. A 70-year-old woman presented with metastasized breast cancer to the bones. An evaluation of the computed tomographic scan was made, which showed an enlarged uterus with a tumor. The tumor was a leiomyoma in which a leiomyosarcoma with osteoclast-like giant cells as well as a metastasis of a ductal breast carcinoma was present. To our knowledge, this is the first report of a leiomyosarcoma containing osteoclast-like giant cells, present in a leiomyoma, in a uterus also containing a ductal breast cancer metastasis present in the leiomyoma and myometrium.

Giant cell tumor of the uterus: case report and response to chemotherapy

Background

Giant cell tumor (GCT) is usually a benign but locally aggressive primary bone neoplasm in which monocytic macrophage/osteoclast precursor cells and multinucleated osteoclast-like giant cells infiltrate the tumor. The etiology of GCT is unknown, however the tumor cells of GCT have been reported to produce chemoattractants that can attract osteoclasts and osteoclast precursors. Rarely, GCT can originate at extraosseous sites. More rarely, GCT may exhibit a much more aggressive phenotype. The role of chemotherapy in metastatic GCT is not well defined.

Case presentation

We report a case of an aggressive GCT of the uterus with rapidly growing lung metastases, and its response to chemotherapy with pegylated-liposomal doxorubicin, ifosfamide, and bevacizumab, along with a review of the literature.

Conclusion

Aggressive metastasizing GCT may arise in the uterus, and may respond to combination chemotherapy.

Uterine sarcomas

A wide variety of sarcomas occur in the uterus but two subtypes - leiomyosarcoma and endometrial stromal sarcoma - account for a majority of those more routinely encountered. Using the 2003 World Health Organization classification, this review focuses on six uterine sarcomas: endometrial stromal sarcoma, undifferentiated endometrial sarcoma, leiomyosarcoma, rhabomyosarcoma, angiosarcoma and liposarcoma. The epidemiological, clinical, pathological and molecular features are presented along with therapeutic approaches. Familiarity with molecular aspects of these tumors and application of novel technologies in their assessment should be encouraged as they may provide alternate therapies resulting in improved survival for the patient. Clinical information necessary for accurate diagnosis of these lesions is emphasised. A multidisciplinary approach to management of patients with uterine sarcomas is essential for optimal management.

Uterine leiomyosarcoma with osteoclast like giant cells and long standing systemic symptoms

INTRODUCTION

The leiomyomatous type of uterine sarcoma with osteoclast-type giant cell component is a rare variant of uterine tumors with poor prognosis. The histological diagnosis of these rare tumors can be problematic and only five such tumors have been published previously.

CASE REPORT

A 54-year-old woman presented with fever and weight loss for 7 months and laboratory findings suggestive of inflammation. After extensive clinical investigation, a uterine tumor was found, which was considered to be an incidental finding and was thought to be unlikely to explain the symptoms. After hysterectomy, the patient had a surprising and quick recovery with the complete relief of systemic symptoms and normalization of laboratory changes. The tumor was a dedifferentiated leiomyosarcoma with osteoclast-like giant cells and contained extensive necrosis. The patient continues to do well and is tumor-free 1 year after the operation.

DISCUSSION

To our knowledge, this is the first report of a patient being alive and disease-free 12 months after surgery with a dedifferentiated uterine leiomyosarcoma with osteoclast-like giant cells.

An endometrial stromal tumor with osteoclast-like giant cells

Endometrial stromal tumors (ESTs) of the uterine corpus have a striking propensity to display diverse morphological variations, including sex cord-like, smooth muscle, or skeletal muscle differentiation; fibrous change; myxoid change; or bland endometrioid-type glands. They may also contain rhabdoid, foam, clear, or epithelioid/granular cells among others. Recently, we have encountered an EST showing smooth muscle differentiation and osteoclast-like giant cells that were predominantly concentrated in the areas showing smooth muscle differentiation. Osteoclastlike giant cells have not been previously reported in EST to our knowledge; thus, this finding expands the morphological spectrum of these tumors. In addition, although the level of infiltration at the peripheries of the tumor exceeded that allowable under the Tavassoli and Norris criteria for stromal nodules, it did not reach the classic permeative infiltration generally associated with endometrial stromal sarcomas. Historical, prognostic, and diagnostic aspects of margins in EST, especially in those borderline cases such as ours, are also discussed.

Malignant gastrointestinal leiomyosarcoma and gastrointestinal stromal tumor with prominent osteoclast-like giant cells

CONTEXT

One case of leiomyosarcoma and one case of gastrointestinal stromal tumor with prominent osteoclast-like giant cells have so far been reported in the digestive tract.

OBJECTIVE

To ascertain the clinicopathologic features and biologic behavior of these tumors, we report 3 additional cases of leiomyosarcoma of the gastrointestinal tract and one malignant gastrointestinal stromal tumor.

DESIGN

Histologic and immunohistochemical examinations were performed. Clinical and follow-up data were recorded, and the literature was reviewed.

RESULTS

The age of the patients ranged from 50 to 68 years (mean, 62 years). One of the lesions arose in the stomach, one in the ileum, and 2 in the colon. Three tumors showed a strong positivity for muscle actin and desmin and were diagnosed as leiomyosarcomas, 2 of them showing spindle cells and 1 of them showing epithelioid cells. The fourth tumor reacted strongly positive for c-Kit (CD117) and vimentin, and it was diagnosed as an epithelioid malignant gastrointestinal stromal tumor. All tumors were characterized by numerous osteoclast-like giant cells that were unevenly distributed and that, using immunohistochemistry, reacted strongly with CD68.

CONCLUSIONS

Malignant stromal tumors with osteoclast-like giant cells of the gastrointestinal tract are rare entities, are more commonly of a myogenic origin such as leiomyosarcoma, and seem to have an aggressive behavior.

Dumbbell-shaped leiomyosarcoma of the inferior vena cava with foci of rhabdoid changes and osteoclast-type giant cells

An inferior vena cava (IVC) tumor was incidentally found in a 67-year-old Japanese man. The resected tumor was lobulated and multinodular, measuring 14.0 x 6.5 x 7.0 cm, showing a dumbbell-shaped appearance with a central constriction. The tumor showed both intra- and extra-luminal growth. The tumor was primarily composed of well-differentiated leiomyosarcoma. Spindle tumor cells in the well-differentiated area were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin. Foci of rhabdoid cells and osteoclast-type multinucleated giant cells were also found. Rhabdoid cells ultrastructurally had paranuclear aggregates or whorls of intermediate filaments that were positive for vimentin, low molecular weight cytokeratin, and desmin. Osteoclast-type multinucleated giant cells were positive for only CD68 antigen, suggesting a reactive histiocytic lineage. To the best of our knowledge, this is the first case of IVC leiomyosarcoma accompanied by both rhabdoid tumor cells and osteoclast-type reactive multinucleated giant cells. These unusual features should be kept in mind in the diagnosis of dumbbell-shaped retroperitoneal tumors that involve the IVC.

Leiomyosarcoma of the Uterus with Focal Rhabdomyosarcomatous Differentiation

An unusual myometrial tumor was encountered in a 70-year-old female who presented with lower abdominal fullness and symptoms related to pulmonary metastases. Laparotomy revealed a uterine mass that was removed by total abdominal hysterectomy and bilateral salpingo-oophorectomy. Multiple liver metastases also were noted. Pathologic examination of the hysterectomy specimen revealed a 25-cm, well-circumscribed myometrial mass that had a firm, white-to-yellow, focally whorled, sectioned surface with focal hemorrhage and necrosis. Within the main mass was a discrete, 7-cm, soft, gelatinous, reddish-yellow nodule. The main tumor was a well-to-moderately differentiated leiomyosarcoma, whereas the gelatinous nodule was rhabdomyosarcomatous and contained rhabdomyoblasts that exhibited cytoplasmic cross striations and immunoreactivity for myoglobin. No epithelial elements were detected in the neoplasm. At the time of last follow-up, the patient was undergoing chemotherapy. This is only the second well-documented case of a hybrid leiomyosarcoma-rhabdomyosarcoma of the uterus.

Osteoclastoma-like Giant Cell Tumor of the Lung

The main components of an unusual form of lung tumor were osteoclast-like multinucleated giant cells and mononuclear stromal cells. Besides, scattered islands of moderately differentiated squamous cells also appeared. Both the mononuclear and the osteoclast-like giant cells reacted with antibodies against CD68 and vimentin, but did not react with antibodies against cytokeratin, EMA and CEA, or lysozyme and a-1-antitrypsin. The p53 and PCNA antigens were positive only in mononuclear cells and not the osteoclast-like giant cells, suggesting that mononuclear cells represent proliferating elements with histiocytic differentiation while osteoclast-like giant cells are stromal, presumably reactive components of the tumor.

The pathology of uterine smooth muscle tumors and mixed endometrial stromal-smooth muscle tumors: a selective review with emphasis on recent advances

This review focuses on the pathology of uterine smooth muscle tumors (SMTs), with a particular emphasis on those studies published in the past 15 years that have expanded our knowledge of these tumors which still present diagnostic challenges for the pathologist. Leiomyoma variants, leiomyosarcoma, SMTs of low or uncertain malignant potential, epithelioid SMTs, SMTs with unusual growth patterns, and mixed endometrial stromal-SMTs are discussed.

Giant cell tumor of bone: frequent actin immunoreactivity in stromal tumor cells

Although giant cell tumor (GCT) of bone is a well-recognized neoplasm with distinctive clinical and histopathological features, the origin of tumor cells, particularly of mononuclear cells, has not yet been established. An immunohistochemical study was carried out on 11 cases of GCT of bone to examine the cellular natures of stromal mononuclear cells. In all cases, stromal cells were positive for muscle actin (HHF35) or alpha-smooth muscle actin, and in eight of 11 cases, positivity was intense and extensive. The cell margin of osteoclast-like giant cells (OGC) was stained positively by muscle actin, in addition to intense and diffuse positive staining of the cytoplasm for KP1 (CD68), whereas alpha-smooth muscle actin exhibited a negative reaction on the OGC. In conclusion, the tumor cells with muscle actin and alpha-smooth muscle actin positivities are not rare but frequently numerous in the GCT of bone; whereas further observation is necessary to elucidate whether the stromal cells exhibit myofibroblastic cell differentiation exactly.

Uterine leiomyosarcoma with osteoclast-like giant cells: histopathological and cytological observations

A 56 year old woman presented with abnormal uterine bleeding. Except for a myomatous uterus, no other abnormalities were noted on physical examination and in radiographic and serologic studies. The hysterectomy specimen revealed an 8 cm uterine fundic tumor composed of two histologically different patterns that merged with one another; one was a well differentiated leiomyosarcoma and the other a mixture of osteoclast-like giant cells (OGC) and plump spindle cells whose cell borders blended, resembling the histology of giant cell tumor of bone. Immunohistochemical studies showed positive staining for muscle actin, alpha-smooth muscle actin, and KP-1 (CD68) in both the spindle cells and OGC. The latter also stained for alpha-1-antitrypsin and alpha-1-antichymotrypsin. These findings suggested that OGC may be formed by the fusion of spindle cells of leiomyosarcoma and also express histiocytic markers.

Leiomyosarcoma of soft tissue and pulmonary metastasis, both with osteoclast-like giant cells

A case is described of leiomyosarcoma with osteoclast-like giant cells in soft tissues which metastasised to the lung. The secondary tumour also contained abundant osteoclast-like giant cells, which raises the question of whether they were locally induced or whether they metastasised with the tumour.

Giant cell tumor of the lung: an autopsy case report with immunohistochemical observations

Tumors resembling giant cell tumor (GCT) of bone are well known to occur in other organs and many cases have been reported to date. While GCT occurring as primary lesions in the lung are extremely rare, the authors experienced such a tumor at an autopsy of a 77 year old woman and subsequently performed histological and immunohistochemical examinations. The clinical and morphologic characteristics of this case are documented, and the literature concerning this type of tumor is reviewed. The present tumor of the lung was histologically characterized by proliferation of benign-looking osteoclast-like giant cells in association with slightly atypical mononuclear cells. The tumor cells were immunohistochemically positive for histiocytic markers but negative for epithelial markers. This case appears to be the first reported benign giant cell tumor of the lung in which histiocytic differentiation of mononuclear cells was suggested by immunohistochemistry.

Histological and immunohistochemical observations of dedifferentiated leiomyosarcoma of the uterus

A case of dedifferentiated leiomyosarcoma of the uterus was examined using immunohistochemistry. The tumor arose in the myometrium, and was a whitish large nodule with hemorrhage and necrosis. Histologically it was a well differentiated leiomyosarcoma with foci showing epithelioid pattern, and in part resembling malignant fibrous histiocytoma (MFH) and giant cell tumor (GCT). Additionally, small round neoplastic cells arranged in an alveolar manner, simulating alveolar rhabdomyosarcoma, were seen in some areas. Neoplastic cells in well differentiated areas expressed desmin, muscle-specific actin and LeuM1, whereas those in epithelioid and poorly differentiated areas lacked these antigens. Instead, tumor cells in epithelioid and small round cell areas were positive for keratin. Interestingly, most tumor cells in well differentiated, epithelioid and small round cell areas were also positive for MB1. However, tumor cells in GCT- and MFH-like areas reacted with none of the antibodies used. Ultrastructurally, some tumor cells possessed various amounts of microfilaments with or without dense patches, whereas others lacked them. These findings suggest that the divergent antigen expression was attributable to different levels of differentiation, and that poorly differentiated components had lost their native features.

Malignant giant cell tumor associated with leiomyosarcoma of the uterus

A unique association of uterine malignant giant cell tumor (MGCT) with leiomyosarcoma (LMS) is described. Contrary to the true mixed sarcomas, they appeared as two adjacent tumors with distinctly different gross, histologic, ultrastructural, and immunohistochemical features and little intermixing at their border. The dissemination of MGCT resulted in the fatal outcome 81 days after hysterectomy. Malignant giant cell tumor and LMS were coexistent neoplasms, which derived probably from different progenitor cells. It is suggested that MGCT could develop in association with preexisting LMS.

Squamous cell carcinoma of the larynx with osteoclast-like giant cells

An unusual squamous cell carcinoma of the larynx containing numerous multinucleated osteoclast-like giant cells in described. These cells occurred in areas of vigorous angiogenesis and haemorrhage. To our knowledge, this is the first case of laryngeal squamous cell carcinoma with osteoclast-like giant cells reported in the literature. The patient has remained alive and free of clinical disease 5 years and 4 months after the original diagnosis.

Malignant osteoclast-like giant cell tumor associated with a uterine leiomyosarcoma

An unusual case of osteoclast-like giant cell tumor associated with a leiomyosarcoma of the uterus is described. The mononuclear cell component of the giant cell tumor was cytologically malignant and the giant cell tumor was present in a biopsy of vaginal recurrence. The patient expired 17 months after diagnosis with extensive tumor despite surgical and radiation treatment. This is the first report of malignant osteoclast-like giant cell tumor associated with a uterine leiomyosarcoma and only the third report of osteoclast-like giant cell tumor in the uterus.

Primary osteosarcoma of the uterine corpus. Report of a case and critical review of the literature

Uterine osteosarcoma represents an extremely rare pure heterologous sarcoma of the uterus. In the present case osteosarcoma occurred primarily in the uterine cavity of a 56-year-old woman. The tumor was anaplastic and the presence of different proliferative patterns caused differential diagnostic problems with various malignant tumor types. The osteoid features of extracellular matrix were demonstrated by electron microscopy. Clinical and pathological features of previously reported cases of uterine osteosarcoma are critically reviewed.

Osteoclast-type giant cell tumour of the pancreas

A case of osteoclast-type giant cell tumour of the pancreas is described and the features of eight other previously reported patients are reviewed. Characteristically, these neoplasms are large at presentation and show focal haemorrhage and necrosis, but seem slow to give rise to metastases. Histological examination reveals numerous osteoclast-like giant cells set in a sarcomatous stroma, the appearances being similar to those seen in giant cell tumours of bone. They are distinct from pleomorphic giant cell carcinomas of the pancreas and may have a slightly better prognosis after resection than ordinary adenocarcinomas. The histogenesis of these rare tumours is unknown.

Cytologic and ultrastructural studies of a rare breast carcinoma with osteoclast-like giant cells

An unusual case of breast carcinoma with osteoclast-like giant cells (OGCs) was reported, for which the diagnosis was made by aspiration biopsy. The OGCs appeared to derive from large mononuclear cells, probably via their cellular fusion. The mononuclear cells had abundant lysosome-like granules, endoplasmic reticulum, and mitochondria. They were thought to be histiocytic cells, though active phagocytosis could not be demonstrated. Histologically, the tumor showed a pattern of well differentiated ductal adenocarcinoma, of which the stroma was crowded with histiocytic cells, OGCs, and lymphocytes. Marked hemorrhage and fibrosis were also seen. The tumor cells tended to be distorted and greatly diminished in accord with the accumulation of OGCs.

Myoepithelioma of the external auditory canal

A Case of myoepithelioma of the external auditory canal is reported. Deapite the presence of significant mitotic activity this tumore showed a benign biological behaviour as evidenced by the 7-year disease-free follow-up.

Myoepithelioma, a variant of pleomorphic adenoma composed predominantly of myoepithelial cells (Batsakis, 1979), has been reported with increasing frequency. This report desceibes a myoepithelioma of the external auditory canal, an anatomic site which has not previously been reported for this tumor type.

Monophasic synovial sarcoma, epithelioid sarcoma and chordoid sarcoma: ultrastructural evidence for a common histogenesis, despite light microscopic diversity

Ultrastructural examination of six rare sarcomas--four monophasic spindle cell tumours, one epithelioid sarcoma, one chordoid sarcoma--has revealed marked similarities at the electron microscopic level despite widely divergent light microscopic appearances. These features consisted of: 1 the presence of two cell types, viz. a clear cell and a cell resembling the fibroblast; 2 pseudoglandular spaces with projecting microvilli or filopodia, and with related tight junctions; 3 an amorphous intercellular ground substance with focal condensation into recognizable basement membrane. The findings suggest a common maturation of these diverse tumours to synovial-like tissue, and support the proposal of Hajdu Shiu & Fortner (1977) that these be considered variants of synovial sarcoma. Published ultrastructural studies of synovial, epithelioid and chordoid sarcoma are reviewed in the light of these findings. The ultrastructural differentiation of synovial sarcoma from extraskeletal myxoid chondrosarcoma, chordoma and the spectrum of malignant spindle cell tumours is discussed.

[Multinucleated giant cell tumor of the thyroid: an unusual anaplastic carcinoma (author's transl)]

Neoplasms of the thyroid with multinucleated, osteoclast-like giant cells, are rare. The numerous giant cells observed in these undifferentiated neoplasm have extensive eosinophilic cytoplasm and contain two to several hundred round or oval, uniform small nuclei. The clinical and morphologic data obtained from the two cases we describe and seven others collected from the literature are as follows: a) peak incidence in late adulthood; b) frequent association with a preexisting goiter (6 cases); c) rapid growth and fatal outcome within one year following diagnosis (5 cases); d) histologic pleomorphism with a background of uniform and spindle- or bizarre-shaped mononuclear cells; e) occasional coexistence of multinucleated giant cell tumor with well differentiated follicular carcinoma (1 case). Indirect evidence suggests that the multinucleated giant cells which characterize these unusual anaplastic carcinomas are epithelial in origin.

Malignant schwannoma: a light microscopic and ultrastructural study

The light microscopic and ultrastructural features of 3 cases of malignant schwannoma were studied and compared with those of other types of soft-tissue sarcoma. The tumor in 1 of these cases originated in an intercostal nerve and was composed of compactly arranged spindle-shaped tumor cells. The other 2 cases showed osteogenic areas in addition to exhibiting prominent nuclear palisading, focal myxoid changes, and a rosette-like arrangement of tumor cells. The tumor in 1 of these latter cases occurred at the site of a preexisting neurofibroma. The Schwann cell origin of these tumors is strongly supported by the ultrastructural findings of basement membranes and conspicuous intercellular junctions in all 3 cases and dense-core granules in 1.

Retroperitoneal leiomyosarcoma: a light and electron microscopic study

Retroperitoneal leiomyosarcoma arising in a spermatic blood vessel is described. In addition to typical leiomyosarcoma, areas of atypical histiocyte-like cells and storiform pattern bearing a close resemblance to malignant fibrous histiocytoma, were seen. Ultrastructurally, cells with features of smooth muscle, partially differentiated cells with marginal densities and basal lamina and histiocyte-like giant cells were present. Phagocytosis of inflammatory cells by tumour cells with marginal densities and an investment of basal lamina was observed. It is suggested that the precursor cell in this lesion was a primitive mesenchymal cell showing varying degrees of smooth muscle differentiation and giant cell formation.

Carcinoma of the breast with multinucleated reactive stromal giant cells. A light and electron microscopic study of two cases

Two unusual carcinomas of the breast are described, containing nests of infiltrating neoplasm situated within stromal lacunar spaces, and surrounded by numerous benign appearing multinucleated giant cells. Within the stroma, there was extensive hemorrhage, hemosiderin pigment deposition, and large numbers of mononucleated inflammatory cells. The morphology of both tumors resembled the giant cell tumor of bone. Although a similar giant cell reaction has recently been described in association with a uterine leiomyosarcoma, we are aware of only two other examples of this entity in the breast, both reported over 40 years ago in the French literature. This is the first report in which electron microscopy confirmed the benign histiocytic nature of the giant cells. These cells had many of the ultrastructural features of multinucleated giant cells described in tissue culture, skeletal osteoclastomas, and foreign body granulomas. We propose that the giant cells arise from fusion of mononucleated stromal cells, and most likely are reactive histiocytic elements which are in some way related to the tumor cell nests. Further studies of these unusual neoplasms are needed to determine if the giant cell reaction in any way affects the prognosis of the patient.

Giant cell tumor of soft parts. An ultrastructural study

The light-microscopic and ultrastructural findings in a case of so-called giant cell tumor of soft parts, localized at the dorsal side of the left foot of a 23-years-old male are described. An amputation of the lower extremity was performed and subsequently chemotherapy with adriamycin was given for 3 months. Despite the histology and cytologic malignant appearance and the evident vascular invasion, already present at the time of the first excision, the last known status 2 years later seems favorable. There are no pathologic lymph nodes in the groins and no signs of metastases on chest X-rays. From the electron-microscope study no definite conclusion can be drawn as regards the histogenesis of this tumor. we feel, as do others, that many of the principal mononuclear tumor cells are poorly differentiated mesenchymal cells. Some of the neoplastic cells, however, show ultrastructural features suggestive of chondro- or osteoblasts (a well-developed r.e.r. containing electron-dense material; multiple Golgi complexes; masses of glycogen; interdigitating cell membrane villi; cytoplasmic filaments; an extracellular amorphous matrix). Some of the larger tumor cells have the submicroscopic aspects of histiocytes as described in osseous, cutaneous, or pulmonary lesions of the histiocytosis X group. As yet undetermined cytoplasmic inclusion bodies constitute another rare observation in our material.