A challenging case of primary orbital mesenchymal chondrosarcoma

Mesenchymal chondrosarcoma is an uncommon lesion of the bone and extraskeletal tissue involving very rarely the orbit. Histopathological features of this lesion include: undifferentiated mesenchymal cells with islands of mature hyaline cartilage. We present a case of a 23-year-old man with primary orbital mesenchymal chondrosarcoma (OMC) with an uncommon management. This anecdotic report could be a contribution to the understanding of this unusual tumor.

Mesenchymal chondrosarcoma of the left coronoid process: report of a unique case with clinical, histopathologic, and immunohistochemical findings, and a review of the literature

Mesenchymal chondrosarcoma (MCS) is a rare malignant neoplasm of bone or soft tissue origin, locally aggressive, rare in the oral cavity, of which fewer than 100 cases have been reported in the English literature. This is the first case described of this type of tumor affecting the coronoid process. The report describes a unique case of MCS in a 64-year-old woman who presented with swelling and pain at the left preauricular area just anterior to the left tragus. An orthopantomograph showed a large mass in the temporomandibular joint involving the left coronoid process and extending to the left ramus of the mandible. Biopsy and histopathologic examination revealed a biphasic pattern, composed of an undifferentiated small round-cell component surrounding a myxoid of malignant cartilage; a focally pericytic vascular pattern resembling hemangiopericytoma was observed. Immunohistochemical studies were positive for CD99, S-100, and CD45 and negative for desmin, actin, chromogranin, epithelial membrane antigen (EMA), and cytokeratin. The tumor was treated by extensive hemimandibulectomy followed by reconstruction of the area. There was no evidence of disease at the 8-year follow-up. Previously reported cases are reviewed as well.

Congenital mesenchymal chondrosarcoma of the orbit

PURPOSE

To report the first case of congenital extraskeletal mesenchymal chondrosarcoma arising in the orbit.

DESIGN

Interventional case report and review of the literature.

METHODS

Ophthalmologic examination and computed tomography scan of the orbit were performed. Histologic and histochemical examination and immunohistochemistry of the biopsy specimen were evaluated.

MAIN OUTCOME MEASURES

Ocular and systemic disease control.

RESULTS

A 5-month-old girl was seen with a papillomatous lesion in the right lower tarsal conjunctiva present from birth. Histologic examination demonstrated an admixture of undifferentiated mesenchymal cells and islands of mature hyaline cartilage, and immunohistochemistry studies revealing positivity for vimentin and S-100 were consistent with the diagnosis of mesenchymal chondrosarcoma. The patient was treated with combined chemotherapy (ifosfamide, epirubicin, and cisplatin), radiotherapy, and surgery (exenteration). She is alive with no evidence of disease after 4 years of follow-up. Facial asymmetry and dental malformations have developed as late effects. Further reconstructive surgery is planned for the malformations.

CONCLUSIONS

Extraskeletal mesenchymal chondrosarcoma in the orbit is extremely rare. This study reports the first case of congenital extraskeletal mesenchymal chondrosarcoma arising in the orbit (also the youngest patient) both in skeletal and extraskeletal sites. Multimodality treatment (surgery, chemotherapy, and radiotherapy) may lead to long-term survival.

Sox9, a master regulator of chondrogenesis, distinguishes mesenchymal chondrosarcoma from other small blue round cell tumors

Over the last decade, a number of "master regulator" genes that control distinct pathways of mesenchymal differentiation have been discovered. These genes are expressed early during embryogenesis and initiate a cascade of gene expression responsible for specific cell lineage commitment. Thus, identification of their products may allow the classification of seemingly primitive, morphologically uncommitted tumors such as small blue round cell tumors. The transcription factor Sox9 has been demonstrated to be a master regulator of the differentiation of mesenchymal cells into chondrocytes. For this reason, we examined the utility of Sox9 in distinguishing mesenchymal chondrosarcoma (a small cell malignancy thought to be derived from primitive chondroprogenitor cells) from other primitive small cell malignancies. Representative sections from 90 cases of small blue round cell tumors (22 mesenchymal chodrosarcoma, 10 neuroblastomas, 11 rhabdomyosarcomas, 9 Ewing's sarcomas/primitive neuroectodermal tumors, 5 desmoplastic small round cell tumors, 7 small cell carcinomas, 6 Merkel cell carcinomas, 6 small cell osteosarcomas, 7 diffuse large B-cell lymphomas, 7 lymphoblastic leukemias/lymphomas, and 5 extraskeletal myxoid chondrosarcomas) were immunohistochemically stained with antibodies to Sox9 protein. All but 1 mesenchymal chondrosarcoma showed positive nuclear staining in both primitive mesenchymal and cartilaginous components of the tumor. All other types of small blue round cell tumors, as well as the lymphomas and leukemias, were negative for Sox9 protein. These findings confirm that mesenchymal chondrosarcoma has phenotypic features corresponding to the early condensational phase of cartilaginous differentiation. More important, Sox9 may serve as a useful tool in the differentiation of small cell malignancies.

Intracranial meningeal tumours in childhood: a clinicopathologic study including MIB-1 immunohistochemistry

Primary tumours of the meninges with a relatively high tendency for malignant behaviour are uncommon in childhood. This study concerns 18 cases of meningeal tumours in children under the age of 16, of which 13 were meningiomas and five were other tumours arising in the meninges. Meningiomas showed a preponderance in females as in adult series, and the majority were supratentorial in localisation. The percentage of meningeal tumours and meningiomas among all brain tumours in our centre were 3.72% and 2.69%, respectively. Four out of 13 meningiomas were fibroblastic, four were transitional, one was meningothelial, two were psammomatous and two were papillary meningiomas. Seven (38.8%) out of 18 tumours showed anaplastic features, including two papillary meningiomas, two hemangiopericytomas, one mesenchymal chondrosarcoma, one pleomorphic sarcoma and one anaplastic meningeal tumour. Papillary meningiomas with hemangiopericytoma-like solid areas were seen frequently in our cases (15.3%). Meningoangiomatosis was associated with two meningeal tumours. MIB1 (Ki-67) labelling indices (LIs) ranged between 0% and 13.6% (mean 1.83%) in benign, and between 1% and 20% (mean 7.2%) in malignant tumour, including papillary meningiomas. Mean MIB-1 LIs were 5.61% and 1.14% in non-recurrent and recurrent cases, respectively. MIB-1 LIs showed significant differences between benign and malignant meningeal tumours but no significant correlation either with prognosis or recurrence. Despite the fact that brain tumours are among the most common neoplasms of childhood, meningeal tumours are rare lesions, accounting for less than 2% of published series of intracranial neoplasms in childhood [5, 8, 18, 24, 30, 32]. It has been suggested that the clinical and pathological characteristics of meningiomas in this age group differ from those of adults [14, 18, 24, 45]. Besides meningiomas, there are a few reports of other meningeal tumours in childhood and difficulties in differential diagnosis may arise within this group, especially in anaplastic tumours [11, 13, 32, 44, 46]. One of the major problems in meningiomas and some tumours arising in the meninges is the discordance that arises between the histologic appearance of the tumour and behaviour [4]. Several studies have attempted to determine the proliferation potential of meningiomas, including immunohistochemical labelling with monoclonal antibodies to Ki-67, proliferating cell nuclear antigen (PCNA), and bromodeoxyuridine (BUdR); flow cytometric DNA analysis; or argyrophilic nucleolar organizer regions (AgNORs) counting [9, 10, 15, 19, 22, 26, 31, 35, 53]. The studies concerning proliferation markers have contradictory results [9, 10, 15, 26, 31, 42, 53]. MIB-1 detects the same or a similar epitope as the original antibody Ki-67 and reacts with a proliferation associated antigen expressed in all active parts of the cell cycle, G1, S, G2 and M (mitosis), but not in the G0 or quiescent phases [7]. In this study we examined the clinicopathological characteristics and MIB1 values of 18 meningeal tumours in children under the age of 16 years within the last 25 years (from 1970 to 1995).

A case of soft tissue mesenchymal chondrosarcoma metastatic to skin, clinically mimicking keratoacanthoma

We report the first case of metastatic involvement of the skin by a soft tissue mesenchymal chondrosarcoma (MS). A 64-year-old man presented 15 months after resection of a 7.0 cm MS from his left forearm with a rapidly growing, erythematous nodule on the left side of the upper lip. The lesion was clinically interpreted as a keratoacanthoma. The histologic appearance was identical to that of the soft tissue MS; an immunohistochemical stain for CD99 was positive. Lung and bone metastases were subsequently documented. Our case expands the differential diagnosis of malignancies with cartilaginous differentiation that can involve the skin.

Primary extraskeletal mesenchymal chondrosarcoma in fossa poplitea of a 93-year-old woman

We report the case of a 93-year-old female who had developed a primary extraskeletal chondrosarcoma in Fossa poplitea for many years. This rare, highly malignant tumor occurred in unusual location and at unusual age. Histologically, it presented with sheets of primitive mesenchymal cells and islets of well-differentiated cartilaginous tissue. Immunohistochemical preparations revealed a positivity for neuron-specific enolase and vimentin, the cartilaginous portion of the tumor and isolated cells of the undifferentiated area also stained partially for S-100 protein. Three years later, only one metastasis was found in the contralateral lower extremity.

Small cell osteosarcoma of bone: an immunohistochemical study with differential diagnostic considerations

Seventy-nine cases of small round cell tumors involving bone were studied in an attempt to learn whether the immunohistochemical features of the lesions might allow distinction of small cell osteosarcoma from other potential differential diagnostic considerations, including Ewing's sarcoma, atypical Ewing's sarcoma, primitive neuroectodermal tumor, mesenchymal chondrosarcoma, lymphoma, and the Askin tumor. The tissues studied were all formalin-fixed, decalcified, paraffin sections from patients between the ages of 16 and 48 years. With one exception (a small cell osteosarcoma), none of the lesions was cytokeratin positive. Moreover, none of the lesions was epithelial membrane antigen, desmin, factor VIII-related antigen, synaptophysin, or Leu-M1 positive. Accordingly, strong positivity for these antibodies in a majority of tumor cells should prompt inclusion of tumor types other than those listed above in the differential diagnosis. Vimentin positivity was seen in a majority of the tumors studied irrespective of histologic type. Scattered tumor cells (< 25%) showed positivity with antibodies to muscle-specific actin and smooth muscle actin in several of the different tumor types studied. No lesions other than lymphoma were leukocyte-common antigen (LCA) positive; all but two lymphomas were LCA positive, while all but one lymphoma were L26 positive. One (lymphoblastic) lymphoma was LCA and L26 negative. S-100, neuron-specific enolase, and Leu-7 did not prove to be specific for "neural-associated" tumors, but rather appeared in some small cell osteosarcomas, Ewing's sarcomas, atypical Ewing's sarcomas, primitive neuroectodermal tumors, mesenchymal chondrosarcomas, lymphomas, and Askin tumors. Antibody to cell surface antigen HBA71 was positive in three Ewing's sarcomas (two typical and one atypical) and negative in small cell osteosarcoma (three cases), mesenchymal chondrosarcoma (two cases), and lymphoma (one case). While some guidance may be derived from analysis of immunohistochemical staining patterns in a given lesion, the results reported in the present study do not suggest that routine immunohistochemistry alone will permit distinction of these small cell tumors of bone from one another. The value of immunohistochemical studies appears to lie particularly in the use of antibodies to LCA and S-100 protein to distinguish lymphoma and mesenchymal chondrosarcoma, and perhaps antibody to HBA71 to distinguish neural family lesions (such as Ewing's sarcoma), from other small cell tumors, such as small cell osteosarcoma.