Giant cell tumor of soft parts. An ultrastructural study

An approach to pleomorphic sarcomas: can we subclassify, and does it matter?

The term malignant fibrous histiocytoma (MFH) has been supplanted by undifferentiated pleomorphic sarcoma (UPS). Even now, however, a number of pleomorphic neoplasms are classified as UPSs when in fact at least a subgroup of these can be more precisely classified as a pleomorphic sarcoma with a specific line of differentiation. Still others are pseudosarcomas, most commonly sarcomatoid carcinomas. This review will discuss historical aspects of MFH/UPS as well as provide an approach to the pleomorphic malignant neoplasm with a discussion of useful ancillary techniques in the evaluation of such cases.

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.

Giant cell tumors of soft tissue: a clinicopathologic study of 18 benign and malignant tumors

Primary giant cell tumors (GCTs) of soft tissue resembling osseous GCTs are uncommon but distinct entities. Malignant GCTs of soft tissue have been designated giant cell malignant fibrous histiocytomas; however, there is scant data regarding benign GCTs of soft tissue. Eleven benign and seven malignant GCTs of soft tissue were identified from the authors' consultation files and the surgical pathology files of the Vancouver General Hospital and Massachusetts General Hospital. The tumors occurred in adults (eight men, 10 women; age range, 25-89 years; mean age, 54 years) in the extremities (n = 14) and in the trunk, abdomen, and pelvis (n = 4). In each patient the skeleton was normal and there was no history of prior osseous GCT. Tumors ranged in size from 0.8 to 9.0 cm. Eleven occurred in the superficial soft tissue and seven occurred in deep soft tissue. Grossly they were circumscribed and frequently hemorrhagic. Cystic change was present in seven tumors. Nine tumors were partially surrounded by a shell of reactive bone. In all tumors, multinucleated osteoclast-like giant cells were distributed uniformly and evenly among mononuclear cells. The histologically benign GCTs of soft tissue were identical to typical osseous GCTs. The mononuclear cells in these tumors lacked nuclear atypia or pleomorphism, and the mitotic rate within this population was low (mean, three mitoses per 10 high-power fields [HPF]). In the malignant GCTs of soft tissue, the mononuclear cells exhibited anisocytosis, nuclear atypia, pleomorphism, and readily detectable mitoses including atypical forms (mean, 25 mitoses per 10 HPF). None of the benign or malignant tumors exhibited neoplastic bone production. The benign and malignant GCTs of soft tissue demonstrated a similar immunohistochemical staining profile to GCT of bone ( 12 tumors examined), exhibiting strong positive staining for CD68 within multinucleated osteoclastlike cells, and focal staining of mononuclear cells for CD68, Ham 56, and smooth muscle actin. All tumors were treated by surgical resection. Follow-up information is available for 15 patients (range, 0-108 months). No benign tumor has recurred or metastasized. Of the four patients with malignant tumors for whom follow-up information is available, one died of metastatic disease at 13 months and one developed a local recurrence at 84 months but is alive, apparently free of disease after additional excisional surgery. Primary GCTs of soft tissue are distinctive neoplasms that, like osseous GCTs, exhibit a wide clinicopathologic spectrum. These neoplasms should be distinguished from other giant cell-rich soft-tissue tumors with which they may be confused.

Osteoclasts are present in the giant cell variant of malignant fibrous histiocytoma

We assessed the osteoclast-like giant cells in a giant cell-rich variant of malignant fibrous histiocytoma (MFH) for characteristics which are specific for osteoclasts, including excavation of bone and binding of osteoclast-specific monoclonal antibodies. Excavations characteristic of osteoclastic activity were found when the bone slices were inspected in the scanning electron microscope after incubation. Two monoclonal antibodies which bind specifically to osteoclasts showed strong membrane reactivity. These results provide strong evidence for the osteoclastic nature of the giant cells in this variant of the MFH. Osteoblasts are known to control the function of the osteoclast, and since there is bone formation present in at least half of the giant cell-rich variant of MFH it may be that it is the cells with properties peculiar to osteoblasts within the tumour which are responsible for the recruitment of the osteoclasts.

Malignant osteoclastoma-like giant cell tumour of the renal pelvis

We report the fourth case of an osteoclastoma-like giant cell tumour of the renal pelvis. A special feature was that although thorough sampling of the tumour showed an osteoclastoma-like pattern throughout, it was intimately associated with carcinoma in situ change of the adjacent transitional epithelium and this provides further support for the view that these tumours are of epithelial derivation. However, immunohistological and ultrastructural studies failed to reveal epithelial features within the tumour cells and the possible significance of this finding is discussed.

Malignant giant cell tumor of soft tissues: a clinicopathologic, cytologic, ultrastructural, angiographic, and microangiographic study

A clinical, angiographic, pathologic-anatomic, and cytologic study of 12 cases of malignant giant cell tumor of soft tissues is presented. Preoperative angiography was performed in five cases, one of which was also studied by microangiography. Aspiration cytologic examination was performed in five cases and electron microscopy in one case. In nine cases the tumors were deeply situated and in three they were subcutaneous. In six cases the tumors were located within the lower extremity, in four cases in the upper extremity and shoulder, in one case retroperitoneally and in one case in the neck. Except for one case, the follow-up period was 1--14 years. Seven of the patients had died from metastasizing tumor disease at the time of follow-up. High vascularity and rapid circulation characterized the tumors at preoperative angiography. Conventional histology, aspiration cytology, and electron microscopy disclosed histiocyte-like cells, fibroblast-like cells, and multinucleated giant cells of both osteoclast-like benign and pleomorphic malignant type, in varying proportions. The histiocyte-like cells and the giant cells exhibited phagocytic activity at these examinations. The finding of phagocytosing pleomorphic malignant cells and giant cells of osteoclast type in aspiration cytologic material strongly favors the diagnosis of malignant giant cell tumor of soft tissues.

Giant cell tumor of the ovary

A 31 year old woman with primary sterility was found, at operation, to have endometriosis of the Fallopian tubes and a giant cell tumor of the ovary, histologically indistinguishable from giant cell tumor of bone. The tumor is considered to be primary and benign, with a follow-up period of 4 1/2 years and no signs of recurrence or malignancy.

[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.

Maglignant giant cell tumor of tendon sheath

A benign, but aggressive, giant cell tumor of tendon sheath developed over a period of 20 years into a metasasizing, histologiclly malignant giant cell tumor. Ultrastructure of the malignant tumor showed the same five cell types as described in giant cell tumors of tendon sheath. Even the same crystals were identified in the osteoblast-like and osteoclast-like cells. It therefore appears reasonable to assume that giant cell tumors of tendon sheath indeed are neoplasms with a malignant potential and not an inflammatory with partial osseous differentiation. No ultrastructural similarities with fibrous histiocytoma were apparent.

Malignant giant cell tumor of bone. Fine structure and localization of acid phosphatase

The fine structure of the different cell types constituting a primary malignant giant cell tumor of bone has been studied and the localization of acid phosphatase in relation to the subcellular organelles been demonstrated. Three distinct cell types with characteristic ultrastructural features were observed: giant cells, fibroblast-like cells, and cells with abundant lipid inclusions and mitochondria. Certain differences were noted between these three cell types and their counterparts in benign giant cell tumors of bone (described in a separate report). The enzyme histochemical and morphological data suggested that the giant cells in the malignant tumor might possess a more active and expansive lysosomal apparatus than corresponding cells in the benign variant.