Chondroblastoma: a study of 11 cases

AIM

Chondroblastoma is an infrequent and unique neoplasm that is histologically characterized by chondroblastoma cells, osteoclast-like giant cells and sometimes reactive osteoid. Although it is generally regarded as benign, it may recur and sporadically metastasize to the lung. Many important questions concerning the prognostic factors and adequate surgical treatment of chondroblastoma have not been fully answered and remain controversial. The purpose of this study was to determine clinicopathological features useful in prediction of the tumour behaviours.

METHODS

Eleven chondroblastoma cases were reviwed clinicopathologically. According to Enneking's radiographic grading system, seven cases were classified as stage I, three cases as stage II and one case was classified as stage III.

RESULTS

Nine cases had initially been treated with simple curettage, one had aggressive curettage applied as a primary surgery and one underwent amputation. Among the nine simple curettage cases, one recurred and was reoperated with aggressive curettage. Adjuvant treatment (alcohol and/or cement) was applied in the two aggressive curettage cases; none demonstrated further tumour recurrence. All lesions were curettaged, and one case recurred. The rate of proliferating-cell nuclear antigen expression was significantly higher in the recurrent case.

CONCLUSION

The recurrent case seemed to have a high growth activity. Simple curettage was effective for local control during the initial treatment in most cases, but aggressive curettage and adjuvant treatment with alcohol and/or cement was useful for local control in recurrent chondroblastoma and chondroblastoma presenting with an aggressive behaviour.

[Usefulness of immunohistochemistry as a diagnostic tool for tumors and pseudotumoral bone lesions]

Immunohistochemical study for the diagnosis of bone tumors and tumor-like lesions has to be scheduled after an appropriate analysis of clinical data, radiological findings, and results of histology in H-E sections. The value of several markers for osteoblasts is discussed, chiefly for various forms of osteosarcomas. In the same way, the role of S-100 protein as well as anticollagen type II antibody is developed for cartilaginous tumors. The selection of markers in the fields of round cell tumors and spindle cell tumors of bone is also discussed. Some diagnostic problems with the support of immunohistochemistry are described, like chordomas versus chondrosarcomas or bone metastases. Lastly, immunohistochemical study of proliferating factors in the bone tumor field is quoted.

Low incidence of genetic alterations of the p16CDKN2a in clear cell chondrosarcoma

Mutational inactivation of the cyclin-dependent kinase inhibitors (CDKIs) (p16CDKN2a) tumor suppressor gene has been found in a variety of human tumor types. To investigate the involvement of CDKI abnormality in clear cell chondrosarcoma, alterations of CDKIs were examined in clear cell chondrosarcoma tissues using a quantitative DNA/PCR, PCR-SSCP. Two of 38 specimens (5.2%) we analyzed showed abnormally low levels of p16CDKN2a amplification, suggesting that the allelic deletion of the gene might be low frequent event in progression of this tumor. For detection of subtle sequence alterations such as point mutations, we performed SSCP analysis of the entire coding region of the p16CDKN2a gene. No altered SSCP patterns were found in 38 clear cell chondrosarcoma specimens. This study reflects the very low incidence of genetic alterations of the p16CDKN2a gene in clear cell chondrosarcoma. Therefore, we conclude that the alteration of the p16CDKN2a gene is not involved significantly in the development of clear cell chondrosarcoma.

Diverse differentiation in malignant peripheral nerve sheath tumours associated with neurofibromatosis-1: an immunohistochemical and ultrastructural study

AIMS

The diverse histological features in malignant peripheral nerve sheath tumours (MPNSTs) associated with NF-1 were investigated by immunohistochemical and electron microscopic analysis. Our study is focused on the differentiation of the tumour cells in the heterogeneous components.

METHODS AND RESULTS

Twenty-three cases were classified as conventional type, epithelioid type, anaplastic type, and heterogeneous type, and divided into three groups by the presence of S100 protein (S100)-positive cells in each tumour; Group A was defined as having >50% S100+ cells, Group B as having <50%, and Group C as cases with no positive cells. To investigate the differentiation of the tumour cells, the morphology and immunoreactivity for neural or mesenchymal markers among the three groups were compared. For the identification of Schwannian, perineurial, and endoneurial differentiation, markers for S100, EMA and CD34 were used, respectively. In three tumours of the Group A type, there were no cases showing differentiation towards perineurial or endoneurial cells, or formation of heterogeneous components. In nine tumours of the Group B type, one tumour expressed EMA and CD34, suggesting probable perineurial and/or endoneurial differentiation. One tumour showed rhabdomyoblastic differentiation. Three tumours showed cartilaginous or osteogenic differentiation, and one of the three also showed a focal vascular differentiation. The surrounding areas of the heterogeneous components were composed of mixed S100+ cells and S100- cells. S100- cells in the areas were positive for CD34 in one case. In 11 tumours of Group C type, one tumour expressed EMA and CD34 suggesting perineurial and/or endoneurial cell differentiation. Three tumours showed rhabdomyoblastic differentiation. The tumour cells around the heterogeneous components in the three cases were negative for EMA and CD34.

CONCLUSION

Our results suggest that tumour cells differentiating to Schwann cells are not the only component of MPNSTs. Furthermore, tumour cells other than Schwann cells are largely related to the formation of the heterogeneous components in MPNSTs associated with NF-1.

Adenosarcoma of the uterine corpus associated with ovarian thecoma

We describe a case of adenosarcoma of the uterine corpus associated with ovarian thecoma in a 67-year-old woman. The patient underwent surgery under a diagnosis of ovarian carcinoma. The 110 x 70 mm-sized ovarian tumor was diagnosed as thecoma. The polypoid tumor of the uterine corpus which measured 30 x 15 mm was diagnosed as adenosarcoma. Cells of both epithelial and stromal elements of the adenosarcoma expressed estrogen receptors (determined by immunohistochemistry). These findings support the view that estrogen stimulation, including that by a pre-existing ovarian thecoma, may play a role in the development of mesenchymal and mixed epithelial / mesenchymal uterine tumors, including adenosarcoma.

Overexpression of p53 and absent genetic mutation in clear cell chondrosarcoma

Clear cell chondrosarcoma is one of the extremely rare chondrosarcomas. The pathogenesis and the molecular genetic events, which contribute to the development of clear cell chondrosarcoma, are not well elucidated, due in part to the lack of sufficient tumor tissue available. To characterize the involvement of the p53 gene abnormality in this disease, we analyzed expression and sequence alteration of p53 by immunohistochemical analysis of the protein expression and quantitative DNA/PCR and PCR-SSCP assays of the gene in 28 paraffin-embedded tissue specimens. Immunohistochemical analysis demonstrated that 7 (25%) showed patchy positive nuclear staining for p53 and 5 (18%) showed diffuse positive nuclear staining patterns. Sixteen (57%) were negative for p53 immunostaining. Quantitative DNA/PCR analysis revealed that none of the cases we studied showed significantly reduced levels of p53 amplification (<0.50), strongly suggesting an allelic deletion of the p53 gene. In contrast, however, DNA/PCR-SSCP analysis failed to detect any types of mutations resulting in amino acid substitution within exons 5-9 regions of the gene. Taken together, our data suggest that genetic alteration of p53 is a relatively rare event in clear cell chondrosarcomas but a substantial fraction of this type of tumors carries abnormal overexpression of p53, which might result from an as yet unidentified mechanism(s).

Carcinosarcoma of the liver

An autopsy case of carcinosarcoma of the liver in an 84-year-old man is described. The 14 x 6-cm solid tumor was located in the hilus to the left lobe and was grayish-white with some translucent areas. Histologically, the tumor consisted of an intimate mixture of adenocarcinomatous and chondrosarcomatous elements with transitional areas in between. Immunohistochemically, cells of the adenocarcinomatous elements were positive for cytokeratin but negative for S100 protein, whereas cells of the chondrosarcomatous elements showed the reverse staining pattern. Cells of transitional areas were positive for both cytokeratin and S100 protein. Most previously reported cases of carcinosarcoma of the liver have involved elderly men and have had a poor prognosis. The findings of the present case support the view that carcinosarcomas represent carcinomas that develop a sarcomatous element via metaplasia of the epithelial element.

p53 gene mutations occurring in spontaneous benign and malignant mammary tumors of the dog

Sixty-three cases of benign and malignant canine mammary tumors were analyzed to define the alteration of exons 5-8 for the p53 tumor suppressor gene using polymerase chain reaction direct sequence analysis with paraffin-embedded tissues. Four missense mutations were found in 38 benign mammary tumors (11%), and five missense (one tumor had two missense mutations) and one nonsense mutations were found in 25 mammary carcinomas (20%). These data suggest that the p53 gene alterations might be initiated at an early stage of canine mammary carcinogenesis and p53 mutations might be associated with malignancy. However, there was no evidence of any relationship between the p53 alterations and the histologic types of tumors or breeds of dogs.

An extremely large solitary primary paraganglioma of the lung: report of a case

We present herein the case of a 38-year-old woman found to have an extremely large solitary primary paraganglioma of the lung. The patient presented with chest pain on exertion and a mass was discovered in the left lower lobe of the lung by chest X-rays and computed tomography (CT). As no other neoplasms were detected elsewhere, a left lower lobectomy was performed. The patient has remained well without any evidence of recurrence for 5 years since her operation. The tumor, measuring 13 x 12 x 7 cm, was composed of ovoid cells (Zellballen), which were positive for Fontana-Masson and Grimelius stains, and sustentacular cells. Immunohistochemically, the ovoid cells were positive for neuron-specific enolase, S-100, CAM5.2, Leu7, and chromogranin A, and negative for carcinoembryonic antigen and epithelial membrane antigen. The sustentacular cells were positive for S-100 protein and CAM5.2, and negative for glial fibrillary acid protein. Therefore, the tumor was diagnosed as a paraganglioma. The tumor from our patient is the largest of the 17 solitary primary pulmonary paragangliomas reported thus far in the English-language literature.

Collagenous fibroma (desmoplastic fibroblastoma): a distinctive fibroblastic soft tissue tumor

Collagenous fibroma is a distinct, benign, fibroblastic/myofibroblastic proliferation, probably neoplasm. It is a slow-growing tumor arising in predominantly subcutaneous tissue. This tumor is composed of stellate-shaped fibroblasts and abundant interstitial collagen. Since none of reported collagenous fibromas recurred, simple excision is an appropriate treatment. Collagenous fibroma should be differentiated from fibromatosis, which has a high risk of local recurrence if simple local excision is done. Fibromatosis is more cellular and shows short fascicular arrangements of tumor cells and greater infiltration at the periphery than collagenous fibroma.

Radiation-induced inflammatory malignant fibrous histiocytoma of the ileum

A case of inflammatory malignant fibrous histiocytoma of the ileum seemingly induced by radiation is described. A 50-year-old female with a past history of uterine cervical carcinoma and postoperative radiation therapy presented with abdominal pain, fever and leukocytosis. The subserosa of the distal part of the ileum showed a diffuse dense, neutrophilic and lymphocytic infiltrate with dispersed atypical, short spindle- or plump oval-shaped histiocyte-like cells. Pleomorphic mono- or multinucleated giant cells with bizarre nuclei were also intermingled in the lesion. Immunohistochemically, the tumorous atypical cells were positive for vimentin, alpha-smooth muscle actin, alpha-1 antitrypsin and granulocyte colony-stimulating factor. No EBV genomic sequences were detected by in situ hybridization. Flow cytometry showed an aneuploid DNA content with high S-phase fraction. The patient was well with no evidence of tumor at 5 months after surgery. It is important to include this type of tumor in the differential diagnosis of small intestinal lesions accompanied by fever and leukocytosis following radiation.

Clear cell chondrosarcoma: a pathological and immunohistochemical study

AIM

Clear cell chondrosarcoma (CCC) is a rare malignant cartilaginous neoplasm of bone. CCC is characterized by clear cells (CCC cells), osteoclasts and osteoblasts. Many important questions concerning the varied histological features of CCC, and the interactions between CCC cells and coexisting osteoclasts and osteoblasts have not been fully investigated and remain controversial. The aim of this study is to clarify and explain the varied histological features and the possible interaction between tumour cells (CCC cells) and stromal cells such as osteoclasts and osteoblasts.

METHODS AND RESULTS

Four cases of CCC were histologically and immunohistochemically studied in order to elucidate the biological nature and histological characteristics. A comparative study with chondroblastoma and grade I conventional chondrosarcoma (CC) was also performed. S100 protein and type II collagen were expressed in CCC cells, chondroblastoma cells and CC cells. CD68 and matrix metalloproteinase-9 were expressed in coexisting histiocytes and osteoclasts. Parathyroid hormone-like protein (PTH-LP) was expressed in histiocytes, osteoclasts, osteoblasts, chondroblastoma cells and CCC cells. Platelet-derived growth factor (PDGF) and its receptor (PDGF-R) were observed in osteoblasts, chondroblastoma cells and CCC cells. However, PTH-LP, PDGF and PDGF-R were not expressed in CC cells. PCNA (proliferating-cell nuclear antigen) was expressed more intensely in CCC than in chondroblastoma.

CONCLUSION

These observations suggest that CCC cells trigger the varied histological changes in association with several cytokines. The difference of PCNA expression between CCC and chondroblastoma seemed to be related to the biological difference between the two tumours.

Osteosarcoma of the metatarsal bone

A case of osteosarcoma arising from a metatarsal bone is reported, focusing on the radiological findings and differential diagnosis.

Proximal-type epithelioid sarcoma in the pelvic soft tissues

A case of proximal-type epithelioid sarcoma arising in the pelvic soft tissues of a 46-year-old man is presented. The tumor showed a predominantly epithelioid component with rhabdoid features, cord-like arrangement, small nests, abundant eosinophilic cytoplasm containing intracytoplasmic, paranuclear, hyaline-like globules, large vesicular nuclei, and prominent nucleoli. There were foci with alveolar arrangement and a spindle-cell proliferation. The tumor cells were positive for cytokeratin CAM5.2, vimentin, epithelial membrane antigen, and CD34. Flow cytometry showed a diploid DNA content with high S-phase fraction. The patient had pelvic lymph-node metastases. He died of the disease 5 months after diagnosis. It is important to include proximal-type epithelioid sarcoma in the differential diagnosis of pelvic tumors.

Expression of vascular endothelial growth factor in N-butyl-N-(4-hydroxybutyl)nitrosamine-induced rat bladder carcinogenesis

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are proteins implicated in tumor-associated microvascular angiogenesis. Expressions of VEGF and bFGF in various stages of chemical-induced rat bladder carcinogenesis were immunohistochemically investigated. Thirty-two male 6-week-old Wistar rats were given drinking water containing 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) for 20 weeks. VEGF and bFGF were not detected in the normal bladder epithelium. In simple hyperplasia, intensive expression of VEGF was observed in a few epithelial cells, and the expression of epithelial VEGF became more pronounced in papillary or nodular (PN) hyperplasia and papilloma. In carcinoma, heterogeneous expression of VEGF was observed in focal tumor cells, intensely expressed in the invading tumor cells. Ultrastructurally, carcinoma cells showed VEGF immunoreactivity in the cytoplasmic matrix and some rough endoplasmic reticulum, and VEGF-positive and -negative carcinoma cells were also clearly defined. High levels of VEGF mRNA were observed in the carcinoma. However, bFGF was not detected in the epithelium throughout the carcinogenesis. Increased microvessel counts appeared at simple hyperplasia and became more pronounced in PN hyperplasia, papilloma, and carcinoma (F-test; P < 0.05). In the carcinoma, the microvessel counts of the VEGF-expressing tumor areas were significantly higher than that of the non-VEGF-expressing tumor areas (U-test; P < 0.05). The present study suggests that upregulation of epithelial VEGF may begin at a quite early stage in BBN-induced rat bladder carcinogenesis, but bFGF may not be involved.

Evaluation of new monoclonal anti-MyoD1 and anti-myogenin antibodies for the diagnosis of rhabdomyosarcoma

New monoclonal anti-MyoD1 and anti-myogenin antibodies were evaluated immunohistochemically to determine whether they are useful in discriminating rhabdomyosarcoma (RMS) from other soft tissue tumors in routinely processed sections. Neither MyoD1 nor myogenin was expressed in normal, mature striated muscle. In RMS, nuclear expression of MyoD1 and myogenin was found in 82 and 80% of non-overlapping cases, respectively. MyoD1 was generally expressed in small, primitive tumor cells, and larger cells exhibiting morphological evidence of skeletal muscle differentiation failed to express positive nuclear immunostaining. Positive nuclear staining for myogenin was stronger than that for MyoD1 in cases with abundant differentiated tumor cells, but was less prominent in cases in which small, primitive tumor cells predominated. No leiomyosarcomas, Ewing's sarcomas/peripheral primitive neuroectodermal tumors or other soft tissue tumors exhibited nuclear expression of MyoD1 or myogenin. In conclusion, both anti-MyoD1 and anti-myogenin antibodies are useful for diagnosing RMS and for discriminating RMS from other soft tissue tumors.

Lymphoepithelioma-like carcinoma of the renal pelvis: a case report with immunohistochemical analysis and in situ hybridization for the Epstein-Barr viral genome

Lymphoepithelial carcinoma is a relatively common malignancy in the nasopharynx, but it rarely occurs at other sites. Described herein is the first case of a renal pelvic neoplasm that closely resembled lymphoepithelial carcinoma, with analyses of histology, immunophenotype, in situ hybridization for the Epstein-Barr viral genome, and flow cytometric DNA ploidy. The tumor was detected in an 70-year-old Japanese man who presented with hematuria Histologic examination showed an undifferentiated round or spindle cell carcinoma (cytokeratin 7+, cytokeratin 20+, epithelial membrane antigen+, vimentin-) with abundant lymphocytes (predominantly UCHL-1+ T cells), plasma cells, and macrophages in and around the tumor cell nests. The tumor was limited to the pelvis, with a minute focus of carcinoma in situ. No Epstein-Barr viral genomic sequences were detected by in situ hybridization. The tumor had an aneuploid DNA content. The patient remains well without disease 6 years after surgery and radiotherapy. Recognition of this type of renal pelvis carcinoma is important to avoid misdiagnosis.

Periosteal Ewing-like adamantinoma

We report a Ewing-like adamantinoma of the periosteal region of the right tibia in a 15-year-old boy. The tumour was well demarcated but unencapsulated and showed cortical bone erosion. Histologically, the neoplastic cells were arranged in trabecular and cord-like patterns with fibrous, hyalinized, and myxoid stroma. Cellular atypia was mild, and mitotic figures were rarely seen. Many tumour cells expressed wide keratin, epithelial membrane antigen, leu 7, synaptophysin, Ewing's sarcoma-related antigen O13, and some were positive for neuron-specific antigen, vimentin, and CD68. The tumour was negative for S-100 protein, desmin, alpha-smooth muscle actin, and muscle-specific actin. Flow cytometric analysis showed that the tumour was aneuploid. After wide excision the patient has been well for the 16 months since diagnosis.

Papillary adenocarcinoma arising in placentoid bullous lesion of the lung: report of a case with immunohistochemical study

We report the case of a 52-year-old man with papillary adenocarcinoma arising in placentoid bullous lesion of the lung, which is a rare cystic lung disease. Macroscopically, the cyst contained a soft villous tumor closely resembling the placental chorionic villi of early gestation. Histologic examination revealed the tumor to be papillary adenocarcinoma with an abundant stromal core, which comprised vascular and lymphatic vessels, lymphocytes, fat cells, and smooth muscle. Immunohistochemically, adenocarcinoma cells were positive for CAM 5.2, epithelial membrane antigen, and PE10 (antisurfactant apoprotein A antibody). These results indicate that the adenocarcinoma was derived from the component epithelial cells of the cyst. Based on the tumor's macroscopic and microscopic appearance and on the results of the immunohistochemical studies, we conclude that the cystic tumor in our case arose in a placentoid bullous lesion of the lung.

Giant cell tumor of bone: a clinicopathologic study of prognostic factors

Forty-seven cases of giant cell tumor of bone were clinicopathologically reviewed to determine any useful prognostic factors. Disease recurred in 11 cases. Eight of these cases had initially been treated with intracapsular piecemeal excision and three cases had been treated with wide excision. Nine of the 11 cases were classified as Grade III, two cases as Grade II, and one case as Grade II + fracture according to Campanacci's radiographic grading system. Intracapsularly excised cases had a high recurrence rate (47.1%). Metastasis to the lung occurred in three cases, each of which had been classified as Grade III. Although the radiographic Grade did not correlate with the rate of lung metastasis or recurrence, cases that metastasized to the lung or recurred tended to be radiographically aggressive. Disease recurred in eight of 24 Grade III cases; but in only two of 12 Grade II cases, in one of five Grade II + fracture cases, and none of six Grade I cases. p53 was expressed by mononuclear stromal cells in six cases. Disease recurred in four and lung metastasis occurred in three of these cases. p53 Expression correlated with rates of lung metastasis and recurrence. It was concluded that cases in which p53 is expressed have a high potential for lung metastasis and recurrence.

Small cell (oat cell) carcinoma of the breast

A case of small cell (oat cell) carcinoma, which represents both the most distinctive and the least common type of breast carcinoma with neuroendocrine differentiation and usually shows the most aggressive behavior, is described. Radical mastectomy was performed on a 56-year-old female for a 10 cm tumor located in the outer part of the right breast with cutaneous ulceration Microscopically, the tumor predominantly consisted of a diffuse proliferation of small, round to ovoid cells with hyperchromatic nuclei and ill-defined, scant cytoplasm that was reminiscent of oat cell carcinoma of the lung. There were foci of invasive ductal carcinoma and ductal carcinoma in situ. Small cell carcinoma areas constituted approximately 90% of the neoplasm. The patient had axillary lymph node metastasis. The small tumor cells were argyrophilic and positive for CAM5.2, carcinoembryonic antigen, neuron-specific enolase, Leu-7, chromogranin A and synaptophysin. Flow cytometric analysis showed an aneuploid DNA content. The patient was alive and well without disease 4 years after surgery. Small cell carcinomas of the breast may exhibit a spectrum of malignancy that is comparable to similar tumors at better known primary sites.

Epithelial metaplastic changes in ovarian endometriosis

Little is known concerning epithelial metaplastic changes (metaplasia) in ovarian endometriosis. Three hundred fifteen consecutive cases of ovarian endometriosis between 1987 and 1995 were retrieved from hospital files and clinicopathologically analyzed. Two hundred fifty-seven cases were not associated with malignant ovarian epithelial tumor or atypia Four cases were atypical endometriosis. The remaining 54 cases were associated with malignant ovarian epithelial tumor, including borderline tumor. Metaplasias in ovarian endometriosis were observed in 162 (63%) cases not associated with malignant epithelial tumor or atypia. Ciliated cell and eosinophilic metaplasias were the most common (44%, respectively), followed by hobnail (13%) and mucinous (4%) types. Metaplasias in endometriosis were observed in all of the four atypical endometriosis cases and all of the 54 cases with malignant ovarian epithelial tumor. Among these cases, ciliated cell and eosinophilic metaplasia were also the most common. There was no correlation between types of carcinoma and types of metaplasia in endometriosis, but in all of the four Müllerian mucinous borderline tumors, ovarian endometriosis with mucinous metaplasia and hyperplasia was contiguous or intimately associated with the tumor. Metaplasia was often observed in ovarian endometriosis and most frequently was associated with malignant ovarian epithelial tumor or atypia. Metaplastic changes in ovarian endometriosis should not be interpreted as neoplastic features. Mucinous metaplasia and hyperplasia in ovarian endometriosis might be closely associated with the development of Müllerian mucinous borderline tumors.

Uterine bizarre lipoleiomyoma

A case of uterine bizarre lipoleiomyoma occurring in a 58-year-old woman is described. A subserosal 8.5 cm mass in the posterior wall of the body had a lipoma-like appearance with strands of fibrous tissue. Histologically, the tumor predominantly consisted of adipocytes which varied in size and shape. Some cells had the appearance of signet ring cells, some had hyperchromatic nuclei, and multivacuolated lipoblasts with hyperchromatic nuclei were observed throughout the lesion. The fibrous areas showed a proliferation of smooth muscle cells with and without atypical nuclei. There was no mitotic figure. Flow cytometric analysis indicated aneuploidy. The patient was well without disease 10 months after hysterectomy. Patients with this type of tumor need a close and long-term follow-up because of the paucity of clinical information.

Giant cell tumor of bone: an immunohistochemical comparative study

Forty-seven cases of giant cell tumor (GCT) of bone were reviewed pathologically to elucidate the origin of spindle-shaped stromal cells or the histogenesis of mononuclear histiocytic stromal cells and osteoclast-like giant cells (OCGC). To clarify the histogenesis of OCGC, eight cases of sarcoma associated with OCGC were reviewed for a comparative study. Spindle-shaped stromal cells sometimes produced minute focl of osteoid matrix. Proliferating cell nuclear antigen (PCNA) was observed in spindle-shaped stromal cells and mononuclear histiocytic stromal cells, but not in OCGC. Matrix metalloproteinase (MMP)-9 was expressed by mononuclear histiocytic stromal cells and OCGC, and its expression was correlated with the lung metastasis rate. In both GCT and sarcomas with OCGC, mononuclear histiocytic stromal cells and OCGC expressed CD68, parathyroid hormone-like protein (PTH-LP), MMP-1 and MMP-9. Immunoreactivity of mononuclear histiocytic stromal cells and OCGC to CD68, PTH-LP, MMP-1 and MMP-9 was similar between GCT and sarcomas with OCGC. These observations may suggest that mononuclear histiocytic stromal cells and OCGC are reactively induced with several cytokines acting in an autocrine or paracrine fashion and that these cells are closely related with the biologic aggressiveness of GCT.

Extrauterine low-grade endometrial stromal sarcoma: report of three cases

Three cases of rare low-grade endometrial stromal sarcoma of the extrauterine tissue are presented. Each one occurred in the ovary, pelvic and abdominal cavities. Two were associated with endometriosis. Histologically, the tumors were characterized by an infiltrative and diffuse proliferation of uniform round or oval cells, abundant small vessels, low mitotic activity, the presence of foam cells and vascular invasion. Immunohistochemically, all tumors expressed vimentin, muscle markers (desmin, muscle-specific actin and alpha-smooth muscle actin) and progesterone receptors. Two tumors were diploid and one was aneuploid by flow cytometry. All patients were well with no evidence of disease 16-39 months after surgery. It is suggested that this neoplasm may arise with or without endometriosis under hormonal influence. This rare variant of Müllerian tumors should not be confused with adenosarcoma and soft tissue tumors, such as smooth muscle tumors and solitary fibrous tumor.

Microvenular hemangioma

A case of microvenular hemangioma in a 23-year-old Japanese female is described. The patient presented with a slowly growing, solitary reddish plague on her back, which measured 15 x 17 mm. Histologically, the tumor was an infiltrative growth throughout the dermis. It consisted of thin-walled, small-sized, irregularly branched vascular vessels. The vascular lumina were narrow. The flattened endothelial cells had oval to spindle-shaped nuclei and scant cytoplasm that were immunohistochemically positive for endothelial markers. The tumor cells lacked cellular atypia, pleomorphism, and mitotic figures. The patient was well without disease 8 months after the excision. Pathologists and clinicians should be aware of the existence of this type of hemangioma with an infiltrative growth and avoid overdiagnosis and overtreatment.

Dissecting leiomyoma of the uterus with extrauterine extension

AIMS

Familiarity with benign uterine smooth muscle tumours with unusual growth patterns by gynaecologists and pathologists is essential in avoiding misdiagnosis and overtreatment.

CASE DETAILS

An enlarged uterus in a 35-year-old woman contained numerous, ill-defined nodules with marked hydropic changes which showed an extrauterine extension. Histologically, although some nodules had an appearance of conventional leiomyoma, the predominant part of the lesion was characterized by ill-defined spindle cell nodules with marked hydropic changes and irregular dissection of the myometrium. The cellularity was variable from area to area and there were neither nuclear atypia nor mitotic figures. No coagulative tumour necrosis was observed. The extrauterine components, which were in continuity with the intrauterine nodule, were histologically identical to the intrauterine nodules except for the complication of endometriosis. Immunohistochemically, the tumour cells were positive for vimentin, desmin, alpha-smooth muscle actin and muscle actin (HHF35). The tumour was DNA diploid by flow cytometry. The patient was well and without disease 6 months after hysterectomy.

CONCLUSIONS

This tumour illustrates that rare benign smooth muscle tumours can proliferate in dissecting and extrauterine growth patterns, findings that should not be confused with malignant mesenchymal tumours.

Pleomorphic hyalinizing angiectatic tumor of soft parts

A case of recently described pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is reported. The subcutaneous solid tumor arising in the axilla of a 58-year-old man was histologically characterized by sheets of mitotically inactive oval and pleomorphic cells, intranuclear cytoplasmic inclusions, and clusters of ectatic vessels with perivascular hyalinization. Mono- and multinucleated giant cells were also present. A hemangiopericytoma-like pattern of vascularity, pseudovascular spaces, stromal collagen with degenerative changes, and immunoreactivity for CD34 were observed. Since these features were very similar to those of solitary fibrous tumors of various sites and newly categorized giant cell angiofibroma, it is considered that PHAT, solitary fibrous tumor, and giant cell angiofibroma may be in the same family of tumor. The tumor was diploid with a low S-phase fraction. The patient was well with no evidence of disease for 23 months.

Giant calcifying epithelioma of Malherbe (pilomatrixoma): imaging features

We present a case of giant calcifying epithelioma of Malherbe (pilomatrixoma) in the right upper arm of a 62-year-old man. It measured 18 x 12 x 8 cm in size, making it the largest of all the cases reported previously. CT clearly demonstrated a well-defined, subcutaneous mass with amorphous calcifications. The mass showed intermediate signal intensity on T2*-weighted MR images and slight contrast uptake on contrast-enhanced MR images. Histopathologically, this tumor showed no aggressive or malignant nature. The patient is without evidence of recurrence or metastasis 3 years following the resection.

Columnar cell carcinoma of the thyroid

A case of columnar cell carcinoma of the thyroid occurring in a 50-year-old female is described. Histologically, the 2 cm tumor showed a prominent papillary architecture with thin fibrous cores covered by columnar cells and marked nuclear stratification. It also showed microfollicular, glandular, and solid patterns. The nuclear features were different to those of conventional papillary carcinoma and similar to those of follicular tumors. The tumor was principally encapsulated with vascular and minimal capsular invasion. The tumor cells were positive for thyroglobulin. The tumor was DNA diploid with a low S phase traction as determined by flow cytometry. The patient had no lymph node or distant metastasis. The patient was well and without disease 9 months after surgery. The possibility that the neoplasm is one of poorly differentiated thyroid carcinomas rises.

Myofibroblastoma of the breast with diverse differentiations

BACKGROUND

The histogenesis of myofibroblastoma of the breast remains unknown.

DESIGN

Two cases of myofibroblastoma of the female breast were analyzed using light microscopy and immunohistochemistry.

RESULTS

The tumors were well circumscribed and predominantly composed of bland bipolar spindle cells and interspersed bands of hyalinized collagen. Additionally, one tumor contained a cartilaginous island, and the other contained a well-defined small nodule that consisted of fascicular arrangements of mitotically inactive atypical cells, simulating atypical leiomyoma. Both lesions contained a fatty element. Immunohistochemically, spindle tumor cells expressed desmin, alpha-smooth muscle actin, muscle actin, and CD34. The atypical cells were strongly and diffusely positive for all these markers. Both tumors were DNA diploid and had a moderate S-phase fraction. The patients have no evidence of disease 4 and 18 months after simple excision.

CONCLUSIONS

Myofibroblastoma of the breast may be a benign mesenchymal neoplasm capable of diverse lines of differentiation.

Endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation: report of two cases with an immunohistochemical and flow cytometric study

Two cases of endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation occurring in a 39-year-old woman and a 42-year-old woman are presented. Both tumors, which were intramyometrial and measured 7.5 cm and 7.0 cm in greatest diameter, respectively, showed a multinodular, ill-demarcated, and yellowish white cut-surface. Histologically, most parts of the tumors were composed of trabecular, cord-like, or plexiform arrangements that were reminiscent of the growth pattern seen in ovarian sex cord tumors. Features of conventional endometrial low-grade stromal sarcoma were only focally observed. The tumors showed infiltrative margins and lymphatic invasion. The tumor cells were positive for vimentin, desmin, alpha-smooth muscle actin, and muscle actin (HHF35). The tumors were also positive for both estrogen and progesterone receptors. Both tumors were DNA diploid as determined by flow cytometry. One patient had recurrences, including osteolytic lesions in the pelvic bones, but had no evidence of recurrence or metastasis 11 months after the last surgery. The other patient had no evidence of tumor in a limited follow-up. Familiarity with the neoplasm and other uterine mesenchymal tumors with ovarian sex cord-like differentiation by gynecologists and pathologists is essential in avoiding misdiagnosis because adjuvant hormonal therapy may be effective in treating low-grade stromal sarcomas.

[Chondroblastoma of the temporal bone: a case report]

A 30-year-old male had been suffering from left temporalgia of six months duration and then developed left hearing disturbance. Craniogram and bone window CT revealed a well defined osteolytic lesion in the left temporal bone. CT scan showed an expansile heterogenous mass with calcification. Both T1 and T2 weighted MRI demonstrated a well lobulated mixed intensity mass, but no evidence of dural or intracranial invasion. The tumor exhibited homogenous enhancement on CT and MRI. Angiogram revealed a well marked staining supplied by the left middle meningeal and deep temporal arteries. Subtotal removal of the tumor was carried out with cranioplasty. Histologically, this tumor was composed of round or polygonal chondroblasts, scattered osteoclast-like giant cells with a foci of cartilage in the stroma. Many reports describe giant cell tumor can be differentiated by immunohistochemical demonstration of S100 protein. Although in our case, histological findings simulated those of eosinophilic granuloma, it was diagnosed as chondroblastoma because of the foci of cartilage in the stroma. Because this tumor is usually benign, recurrence of the tumor is rare after surgical resection. Post-operative irradiation has been reported to be effective in decreasing the recurrence of the tumor. But it should be carefully observed because of possible sarcomatous change in such tumors.

Testicular efferent ductule cyst of a dog

A 9-year-old male Shetland Sheepdog had a small mass in the left testis. Grossly, the round to oval cyst was present at the upper pole of the testicular parenchyma near the head of the epididymis. Histologically, the cyst was lined by a single layer of nonciliated and ciliated epithelial cells. Immunohistochemically, the epithelial cells of the cyst showed expression of the low- and high-molecular-weight cytokeratins, vimentin, and desmin similar to that of normal efferent ductules in the dog. The testicular cystic dysplasia was thought to originate from the efferent ductules.

Extrapleural solitary fibrous tumor: a report of seven cases

Solitary fibrous tumors (SFTs) are rare, spindle-cell neoplasms generally associated with the serosal surface, especially the pleura. Histopathologic, immunohistochemical, ultrastructural, and flow cytometric analyses were performed on seven SFTs of extrapleural sites (two retroperitoneal, two soft tissue, one each peritoneal, nasal cavity, and orbit). Five patients were women, and two were men, aged from 21 to 68 years (average, 39 yr). All of the lesions presented as well-circumscribed masses. The lesions ranged in size from 2 to 20 cm in greatest diameter. Histologically, these lesions were entirely comparable to the pleural SFTs and lacked the characteristic features of other recognized neoplasms that occur in these regions. One tumor contained pleomorphic and round-cell sarcomatous foci. Immunohistochemically, all of the tumors were strongly positive for vimentin and CD34. Six of the seven tumors showed varying numbers of spindle cells positive for alpha smooth muscle actin, HHF35, neuron-specific enolase, Leu 7, or glial fibrillary acidic protein. Ultrastructural examinations of three tumors showed that they were composed of primitive mesenchymal or fibroblast-like cells. Six tumors examined were diploid by flow cytometric examination. Clinical follow-up in six patients ranged from 1 to 7.5 years (average, 2.6 yr) and showed that five patients remained well with no evidence of disease after excision and that the patient with the sarcomatous elements died of recurrence 2.5 years after surgical treatment. These findings suggest that SFTs represent ubiquitous neoplasms of fibroblasts or primitive mesenchymal cells with aggressive potential.

Small cell carcinoma of the ovary: a case report of large cell variant

An extremely rare case of large cell variant of ovarian small cell carcinoma is described. A 34-year-old woman (gravida 1, para 1) had a unilateral ovarian mass measuring 17cm in greatest diameter and a metastatic lesion in the omentum. Microscopically, the tumor showed a diffuse arrangement of large, closely packed epithelial cells with abundant eosinophilic cytoplasm and large nuclei with prominent nucleoli. The tumor cells also were arranged in follicle-like and trabecular structures and cords. Immunohistochemically, many tumor cells were diffusely positive for epithelial membrane antigen and some cells contained cytokeratin CAM5.2, vimentin, neurofilament, neuron-specific enolase, or alpha-1 antitrypsin. However, no specific lineage was detected. The tumor was aneuploid by flow cytometry. The patient received chemotherapy postoperatively. However, the patient showed metastases in the inguinal and retroperitoneal lymph nodes. The serum calcium level, which was not measured preoperatively, was mildly elevated postoperatively. The patient was well with no evidence of disease 17 months after diagnosis. This tumor must be distinguished from other primary or metastatic 'undifferentiated' neoplasms, especially ovarian small cell carcinoma of pulmonary type and granulosa cell tumor.

Small cell neuroendocrine carcinoma of the ovary

A 64-year-old woman (gravida 0, para 0) had a unilateral ovarian mass measuring 14 cm in its greatest diameter, which was mostly solid. Microscopically, the tumour was characterized by two predominant proliferating patterns: a carcinoid-like pattern with trabecular, tubular, glandular, or insular arrangements and a closely packed nesting pattern with central coagulation necrosis and occasional glandular arrangements. These two patterns were intermingled, and numerous mitotic figures were present. Electron microscopy showed neurosecretory granules in the cells, which were argyrophilic and positive for neuroendocrine markers (chromogranin, leu 7, neuron-specific enolase, and synaptophysin). The tumour was aneuploid by flow cytometry. The patient received chemotherapy postoperatively, developed brain and multiple bone metastases and died of disease 10 months after surgery. This tumour must be distinguished from other small cell neoplasms, especially ovarian small cell carcinoma of the hypercalcaemic type.

Chromosomal translocations in human soft tissue sarcomas by interphase fluorescence in situ hybridization

In soft tissue sarcomas, clonal rearrangement of chromosomes has been shown by cytogenetic analysis to be unique and specific for tumor types. The development of fluorescence in situ hybridization (FISH) has allowed detection of chromosomal rearrangements in the interphase nuclei isolated from paraffin-embedded tissues. Three kinds of translocations in the interphase nuclei that were isolated from 47 cases of soft tissue sarcomas were examined by FISH with chromosome-specific DNA probes of centromeric and total probes. Of 47 soft tissue sarcomas 42 (89.4%) revealed tumor-specific translocations by retrospective cytogenetic analysis. Translocation t(X;18) was detected in 25/28 synovial sarcomas; translocation t(11;22) in 5/6 Ewing's sarcomas and primitive neuroectodermal tumors (PNET); and translocation t(12;16) was found in 12/13 liposarcomas, including 10 myxoid and two round cell types as clonal chromosomal aberrations specific for both subtypes. Based on the cytogenetic analysis, Ewing's sarcoma is related closely with PNET as shown by MIC2-protein reactivity. Other cytogenetic findings of translocation t(12;16) indicate that round cell liposarcomas share chromosomal changes with myxoid liposarcomas, and further suggest that both tumor subtypes of liposarcoma may possess common precursor cells. FISH is a useful aid in determining the tumor type of soft tissue sarcomas with regard to histogenetic origin.

Ovarian atypical endometriosis: its close association with malignant epithelial tumours

The incidence of ovarian atypical endometriosis and its association with malignant epithelial tumours in a consecutive series of cases during the period 1987 to 1995 were studied. Atypical glandular changes were observed in four (1.7%) of 255 ovarian endometriosis cases and one patient with ovarian atypical endometriosis developed subsequent endometrioid carcinoma in the abdominal wall. Fifty-four (24.1%) of the 224 ovarian cancers were associated with ovarian endometriosis; 21 with typical and 33 with atypical endometriosis. Clear cell carcinomas and endometrioid carcinomas were most frequently associated with endometriosis, with 54% (27 of 50 cases) and 41.9% (13 of 31), respectively. Atypical endometriosis was found in 18 clear cell carcinomas, in seven endometrioid carcinomas, in four serous carcinomas, in three mucinous borderline tumours, and in one serous borderline tumour. In 13 cases, the atypical endometriosis was in contiguity with malignant epithelial tumours. We consider that atypical endometriosis possesses a precancerous potential or is most frequently associated with clear cell and endometrioid carcinomas. Close screening of cellular atypia or hyperplasia in ovarian endometriosis and careful long-term follow-up of patients with atypical endometriosis is required.

Vulval angiomyofibroblastoma. Clinicopathologic analysis of six cases

Clinicopathologic, immunohistochemical, ultrastructural, and flow cytometric analyses were performed on vulvar angiomyofibroblastomas in six women (ages 32 to 46 years; average age, 41.3 years). The tumors were all well circumscribed, and measured 2 to 9 cm in greatest dimension. Five tumors were clinically diagnosed as Bartholin's gland cysts. At histologic analysis, the tumors were characterized by alternating hypercellular and hypocellular edematous areas with abundant blood vessels. The hypercellular areas showed a perivascular proliferation of spindle-shaped and round cells, which often formed small nests or epithelioid arrangements, and a short fascicular pattern of spindle cells. The proliferating vessels were thin-walled and capillary-sized. Cellular atypia and mitotic figures were absent. Two tumors contained an adipose element, and one showed a prominent vascular proliferation reminiscent of a capillary hemangioma. At immunohistochemical analysis, the tumor cells were strongly positive for vimentin and desmin. Some cells were weakly positive for HHF35 and alpha-smooth muscle actin. Ultrastructurally, one neoplasm showed fibroblastic differentiation. Flow cytometry revealed three tumors were DNA diploid and two were aneuploid. All tumors were excised, and none have recurred (average follow-up, 28.3 months). These results indicate that angiomyofibroblastomas contain heterogeneous components.

Calcifying fibrous pseudotumor

A case of calcifying fibrous pseudotumor arising in the ingune of a 20-year-old Japanese female is described. The patient had a well-circumscribed subcutaneous mass measuring 2.0 cm in greatest diameter, which had been present for 3 months. Microscopically, the tumor was not encapsulated but well defined. The tumor was composed largely of dense interwoven bundles of collagen. Uniform, elongated spindle cells were scattered among the collagenous bundles and showed a wavy pattern. Lymphoid follicles with germinal centers and an infiltration of lymphocytes and plasma cells were intermingled. The tumor was characterized by the presence of microcalcifications, chiefly dystrophic calcifications, throughout the lesion. The spindle cells were diffusely positive for vimentin and alpha-smooth muscle actin. They were uniformly negative for desmin, muscle specific actin HHF35, factor-VIII related antigen, S-100 protein, neurofilament, cytokeratin CAM5.2, CD34, and CD31. By flow cytometry the tumor had a diploid DNA content with S-phase fractions of 2.5%. The patient was well with no evidence of disease 2 months after excision.

Gynandroblastoma of the ovary: a case report with an immunohistochemical and ultrastructural study

An ovarian gynandroblastoma in a 60-year-old woman is described. The cut-surface of the right ovary showed multiple macrofollicles separated by white fibrous tissues and multiple ill-defined yellowish nodules. The tumour consisted of substantial amount of a granulosa cell element and a Sertoli cell element with intermingled Leydig cells. Immunohistochemically, the tumour cells in both the granulosa cell and Sertoli cell elements were positive for cytokeratin CAM5.2. The granulosa cell element showed strong membrane staining of Ewing's sarcoma antigen 013 and the Sertoli cell element was locally positive. Vimentin was observed in both the Sertoli cell element and the granulosa cells. Both elements and the Leydig cells were uniformly negative for epithelial membrane antigen, muscle specific actin, CD31 and CD34. The tumour was aneuploid by flow cytometry. The patient was well with no evidence of tumour five months after surgery.

Chromosomal rearrangement t(11;22) in extraskeletal Ewing's sarcoma and primitive neuroectodermal tumour analysed by fluorescence in situ hybridization using paraffin-embedded tissue

The clonal chromosomal rearrangement t(11;22) has been reported by karyotypic analysis to be specific for Ewing's sarcoma of bone and soft tissue origin as well as primitive neuroectodermal tumour. In this report, immunohistological analysis of MIC 2 expression and fluorescence in situ hybridization (FISH) were performed using paraffin-embedded tissues. We examined t(11;22) in the nuclei isolated from two Ewing's sarcomas, four primitive neuroectodermal tumours, and three neuroblastomas, which served as negative controls by FISH with an alpha-satellite DNA probe for chromosome 11, a chromosome 22 marker probe, and whole chromosome painting probes for both chromosomes 11 and 22. Both cases of Ewing's sarcoma and the four primitive neuroectodermal tumour specimens were immunoreactive for MIC 2. Both Ewing's sarcomas and three of the four primitive neuroectodermal tumours contained the tumour-specific t(11;22), but the three neuroblastomas did not show this translocation. Based on the cytogenetic results and on the immunohistological investigation of MIC 2 expression, Ewing's sarcoma is suggested to be related closely to primitive neuroectodermal tumour. FISH is a useful aid in determining the tumour type of Ewing's sarcoma and putative related tumours.

Carcinosarcoma of the uterus with extensive neuroectodermal differentiation

A case of uterine carcinosarcoma with extensive neuroectodermal differentiation occurring in a 54-year-old woman is described. Microscopically, the endometrial tumour was predominantly composed of a sheet-like proliferation of small- and medium-sized cells. These cells were characterized by fibrillary cytoplasmic processes, rosette-like formations, perivascular palisading patterns, and immunoreactivity for glial fibrillary acidic protein, synaptophysin, leu 7 and neuron-specific enolase. In limited areas, features of conventional carcinosarcoma, including squamous cell carcinoma, leiomyosarcoma and islands of the above mentioned small- to medium-sized cells that were intermingled, were observed. The tumour was aneuploid by flow cytometry. The patient is alive with tumour for three months. It is suggested that at least some cases of uterine primitive neuroectodermal tumour may be explained by one-sided neuroectodermal development within a carcinosarcoma.

Low-grade fibromyxoid sarcoma

A low-grade fibromyxoid sarcoma arising in the thigh of a 16-year-old Japanese girl is described. The patient had a well-circumscribed mass measuring 3.5 cm in its greatest diameter within her left vastus medialis muscle and a 6-month history of pain. Microscopically, the tumour was not encapsulated and filtrated into adjacent skeletal muscle. The tumour was characterized by poor to moderate cellularity, a proliferation of bland-appearing spindle tumour cells, and alternating fibrous and myxoid areas with a whorled pattern of the tumour cells. Neither cellular atypia nor mitotic figures were observed. There was no tumour necrosis. Immunohistochemically, the tumour cells were diffusely and strongly positive for vimentin and desmin. Some cells contained alpha smooth muscle actin. They were uniformly negative for CAM5.2, epithelial membrane antigen, muscle-specific actin (HHF35), factor-VIII-related antigen, S-100 protein, neurofilament, CD34, and CD31. The tumour had a diploid DNA content with S-phase fractions of 6.6% by flow cytometry. The patient was alive with no evidence of disease 11 months after excision.