Bone Pathology for Hematopathologists

Bone pathology can be challenging because the skeleton is a living tissue prone to developing a diverse array of inflammatory, metabolic, genetic, reactive, circulatory, and neoplastic abnormalities. Several areas of bone pathology are particularly difficult or problematic for hematopathologists given the close resemblance of some hematologic entities to primary/metastatic bone lesions; examples include plasmacytic disorders versus osteoblastic tumors and lymphoma/leukemia versus round cell tumors of bone. This article provides a conceptual and practical overview of selective bone disorders commonly encountered in the differential diagnosis of hematologic diseases.

Mesenchymal Chondrosarcoma of the Sacrum: A Case Report and Review of the Literature

The authors present a case of mesenchymal chondrosarcoma located in the sacrum of a 23-year-old patient treated with radiotherapy and chemotherapy. A review of the literature on the topic is also reported.

Quiz. Correct answer to the quiz. Check your diagnosis. Mesenchymal chondrosarcoma of the orbit: two cases and a brief review of the literature

Mesenchymal chondrosarcoma (MChS) is a rare, high-grade malignant tumor which occurs both in the bone and soft tissue. The extraskeletal location comprises one third of all MChS and in review of the up-to-date literature, about 30 cases of the orbital involvement were found. The authors present clinical, radiological and pathological findings of two cases of MChS of the orbit occurring in young adult females: primary extraskeletal MChS of the orbit and skeletal MChS of the ethmomaxillary complex with secondary orbit involvement. The histopathological examination revealed a characteristic biphasic pattern composed of small round to spindle-shaped cells, mimicking Ewing sarcoma family of tumors, with areas of a haemangiopericytoma-like pattern and admixed cartilage foci. One of the patients had local recurrence 3 years after initial surgical removal. Subsequently, she underwent enucleation followed by chemotherapy. The other patient had a biopsy and debulking resection of the tumor and started chemotherapy. Ten months follow-up of this patient show no evidence of metastasis.

Sacral mesenchymal chondrosarcoma in childhood: a case report and review of the literature

Mesenchymal chondrosarcomas are rare malignant tumors in pediatric age group. The authors present a case of mesenchymal chondrosarcoma located in the sacrum in a 10-year-old-girl that was successfully treated with chemotherapy and radiotherapy after surgical excision. According to the authors' literature search, the patient is the first reported case of pediatric sacral primary mesenchymal chondrosarcoma. Mesenchymal chondrosarcoma cases in pediatric age group published in English literature was reviewed.

Case report: Mesenchymal chondrosarcoma of the lumbar spine in a child

BACKGROUND

Chondrosarcomas of the spine constitute 4% to 10% of all primary spinal bone tumors and approximately 70% of the cases occur during the second or third decade of life. Mesenchymal chondrosarcoma is a rare aggressive variant of chondrosarcoma. The prognosis of mesenchymal chondrosarcoma is usually poor with a tendency for late local recurrence and metastasis.

CASE DESCRIPTION

We describe a case of primary mesenchymal chondrosarcoma affecting the L5 vertebra of a 9-year-old girl. The patient underwent a staged circumferential resection of the tumor after three rounds of neoadjuvant chemotherapy. The patient had additional chemotherapy and radiation therapy as an intralesional margin was achieved during the procedure. At 9 years followup, the patient was asymptomatic, neurologically intact, and remained in remission.

LITERATURE REVIEW

We identified only four previously published cases of spinal mesenchymal chondrosarcoma in childhood, two of which had relatively early recurrence and poor survival, and two survived but with only short followup.

PURPOSES AND CLINICAL RELEVANCE

As the clinical and radiographic findings of mesenchymal chondrosarcoma are nonspecific, the diagnosis of this rare tumor requires careful histopathologic review of the specimens. We suggest the differential diagnosis of every primary intraspinal tumor include tumors of mesenchymal origin. The prognosis is apparently not uniformly poor.

The clinical approach towards chondrosarcoma

This review provides an overview of the histopathology, classification, diagnostic procedures, and therapy of skeletal chondrosarcoma. Chondrosarcomas that arise de novo are primary chondrosarcomas, whereas chondrosarcomas developing superimposed on pre-existing benign cartilage neoplasms such as enchondromas or osteochondromas are referred to as secondary chondrosarcomas. Conventional chondrosarcomas can be categorized according to their location in bone into central, peripheral, and juxtacortical chondrosarcomas. Histological grading is related to prognosis; however, it is also subject to interobserver variability. Rare subtypes of chondrosarcoma, including dedifferentiated, mesenchymal, and clear cell chondrosarcoma, are discussed as well. Magnetic resonance imaging is necessary to delineate the extent of the intraosseous and soft tissue involvement preoperatively. Computed tomography is especially recommended in the pelvis and other flat bones where it may be difficult to discern the pattern of bone destruction and the presence of matrix mineralization. Wide, en-bloc excision is the preferred surgical treatment in intermediate- and high-grade chondrosarcoma. In low-grade chondrosarcoma confined to the bone, extensive intralesional curettage followed by local adjuvant treatment and filling the cavity with bone graft has promising long-term clinical results and satisfactory local control. Chondrosarcomas are relatively radiotherapy resistant; therefore, doses >60 Gy are needed in attempts to achieve local control after incomplete resection. Irradiation with protons or other charged particles seems beneficial in this curative situation. Chemotherapy is only possibly effective in mesenchymal chondrosarcoma, and is of uncertain value in dedifferentiated chondrosarcoma. Potential new systemic treatment targets are being discussed.

Primary orbital mesenchymal chondrosarcoma: a case report and literature review

BACKGROUND

Mesenchymal chondrosarcoma (MC) is a subtype of chondrosarcoma, with an incidence varying from 1 to 8% of all chondrosarcomas. It is an aggressive neoplasm with a high tendency for late recurrence and occasional delayed distant metastasis. Orbital MC is very rare, and only approximately 30 cases have been described in the literature. We describe here one case of primary orbital MC.

CASE REPORT

A 14-year-old boy without a past medical history presented with a 1-month history of progressive proptosis on the right eye. Computed tomography (CT) scans of the orbit revealed a right intraconic lesion, with areas of calcification. The lesion was excised. Histopathological analysis revealed that the tumor had a biphasic pattern, showing a combination of small cell malignancy and well-differentiated cartilage. Immunohistochemistry examination revealed a diffuse membrane expression of CD99 on the small cell malignancy; S-100 was positive only within the cartilage component. The patient received chemotherapy, and no metastatic disease was found at the 2-month follow-up.

CONCLUSION

Although rare, MC should be considered in the differential diagnosis of a well-circumscribed orbital lesion in young adults, especially when CT scans reveal areas of calcification within the tumor.

Extraskeletal mesenchymal chondrosarcoma: an imaging review of ten new patients

OBJECTIVE

Extraskeletal mesenchymal chondrosarcoma (EMC) is a rare soft-tissue tumor that most arises in young adults. Because of its rarity, few imaging studies have been reported to date. The purpose of this study was to elucidate the imaging features of this tumor.

DESIGN

We conducted a multi-institutional study in cooperation with five referral cancer centers in Japan. Imaging findings of ten new EMC cases, including conventional radiography, computed tomography (CT), and magnetic resonance imaging (MRI), performed at each institute, were reviewed along with clinical features.

PATIENTS

Ten patients with EMC, who had been treated at each hospital from 1990 to 2001, participated in this study.

RESULTS AND CONCLUSIONS

Soft-tissue masses with well-demarcated, dense and granular calcification were most frequently observed on plain radiographs and CT scans. T2-weighted MR images most clearly depicted a two-component structure composed of calcified and uncalcified areas, and enhanced MRI showed inhomogeneous enhancement in both areas. Although the sensitivity and specificity of these findings are unknown, they might be characteristic and have diagnostic value for this rare tumor.

Central nervous system mesenchymal chondrosarcoma

Central nervous system mesenchymal chondrosarcomas are rare malignant tumors that constitute a separate entity from the classical chondrosarcoma and myxoid variant. Clinical behaviour of central nervous system chondrosarcomas is still unknown. We describe two rare examples of intracranial mesenchymal chondrosarcoma with a review of the literature, in an attempt to clarify the clinical characteristics, prognosis and treatment of choice of these unusual tumors. Among the 55 reported cases, 23 had postoperative radiotherapy. Although there is no statistical significance according to the Log-Rank test (p=0.7), the patients treated with radiation therapy seem to have a better chance of survival. Patients who had adjuvant chemotherapy (only 5) showed survival times similar to those patients who had none. Although clinical behaviour of central nervous system chondrosarcomas remains to be defined, data from our series as well as literature show that radical removal is the best therapeutic choice. In addition, patients treated with postoperative radiotherapy seem to show a trend toward increased survival.

Imprint cytology of extraskeletal mesenchymal chondrosarcoma of the perineum: a case report

BACKGROUND

Extraskeletal mesenchymal chondrosarcoma (EMC) is an uncommon soft tissue tumor, occurring mainly in the lower limbs, meninges and retroperitoneum. EMC of the female genital tract is extremely rare, and the cytologic literature is scarce.

CASE

A 43-year-old female with a growing perineal mass underwent excision of the tumor. Pathologic examination of the rumor revealed a characteristic two-cell pattern of primitive small cells and cartilaginous tissue. A diagnosis of EMC of the perineum was made. Imprint cytology from surgical material showed a cluster of small round cells with a focal hemangiopericytomalike arrangement and islets of cartilage. The cartilaginous cells reacted with S-100 protein immunocytochemically.

CONCLUSION

The characteristic features of EMC, a hemangiopericytomalike arrangement of small cells and S-100-positive cartilaginous cells, may be helpful in diagnosing EMC and differentiating it from other perineal tumors.

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.

Intracranial mesenchymal chondrosarcoma with osteoid formation: report of a pediatric case

CASE REPORT

We present a case of a 14-year-old girl with a 3-week history of severe progressive headache and intermittent vomiting. Magnetic resonance imaging (MRI) revealed a large intensely enhancing mass, which seemed to arise from the right side of the cerebral fossa with implant base in the inferior face of the tentorium and significant mass effect on the nearby structures. A presumptive preoperative diagnosis of meningioma was made. Subtotal surgical resection was performed using the occipital approach. Histologically the neoplasms had the classic features of a mesenchymal chondrosarcoma associated with the focal presence of osteoid matrix.

DISCUSSION

Clinical features, therapeutic approaches and prognosis of this rare tumour are discussed with regard to the known 30 cases in the literature.

Mesenchymal chondrosarcoma of the sellar region

BACKGROUND

It is known that, although rare, mesenchymal chondrosarcoma can originate intracranially. However, no such malignant tumour has been described in the sellar region.

CLINICAL PRESENTATION

We report a case of mesenchymal chondrosarcoma in a 21-year-old man who presented with double vision, right blepharoptosis and facial pain. Upon initial admission, no endocrinological abnormalities were found, and computed tomography and magnetic resonance imaging revealed a mass with calcification in the sella and right cavernous sinus.

INTERVENTION

For this malignant tumour, three surgical resections, two sessions of gamma-knife radiosurgery, one session of fractional irradiation, and one cycle of chemotherapy were performed, resulting in only brief arrest of the tumour growth. Pathologically, the tumour consisted of undifferentiated small cells of high cellularity, and islands of hyaline cartilage. The undifferentiated small cells showed immunoreactivity for vimentin and ultrastructural features suggesting a mesenchymal origin. Lacunar cells in the islands were immunopositive for S-100 protein and vimentin.

CONCLUSION

Although malignant tumours in the sellar region are rare, they should be considered in the differential diagnosis of various sellar tumours typified by non-functioning pituitary adenoma, and mesenchymal chondrosarcoma is one possible candidate.

Mesenchymal chondrosarcoma of the sinonasal tract: a clinicopathological study of 13 cases with a review of the literature

OBJECTIVES/HYPOTHESIS

Mesenchymal chondrosarcoma of the sinonasal tract is a rare, malignant tumor of extraskeletal origin. Isolated cases have been reported in the English literature, with no large series evaluating the clinicopathological aspects of these tumors.

STUDY DESIGN

Retrospective review.

METHODS

Thirteen patients with sinonasal mesenchymal chondrosarcoma were retrieved from the Otorhinolaryngologic-Head and Neck Registry of the Armed Forces Institute of Pathology.

RESULTS

Nine women and 4 men (age range, 11 to 83 y; mean age, 38.8 y) presented with nasal obstruction (n = 8), epistaxis (n = 7), or mass effect (n = 4), or a combination of these. No patients reported prior head and neck irradiation. The maxillary sinus was the most common site of involvement (n = 9), followed by the ethmoid sinuses (n = 7) and the nasal cavity (n = 5). Tumors had an overall mean size of 5.1 cm. Microscopically, the tumors displayed a small, blue, round cell morphology appearance arranged in a hemangiopericytoma-like pattern with foci of cartilaginous matrix. All cases were managed by surgery with adjuvant radiation therapy (n = 4) and/or chemotherapy (n = 3). The overall mean survival was 12.1 years, although five of six patients who developed local recurrences died of disease (mean survival, 6.5 y). Six patients were alive and disease free (mean survival, 17.3 y), and two patients were lost to follow-up.

CONCLUSIONS

Mesenchymal chondrosarcoma of the sinonasal tract is an aggressive tumor with a predilection for young women. The pattern of growth and scarcity of cartilaginous matrix result in frequent misdiagnosis. Recurrence develops in approximately one-third of patients and seems to predict a poor prognosis. Aggressive, exenterative surgery combined with adjuvant therapy appears to yield the best clinical outcome.

Mesenchymal chondrosarcoma of the maxilla

Mesenchymal chondrosarcoma (MC) is a rare tumour, with a predilection for the head and neck region. We describe a case of mesenchymal chondrosarcoma arising in the right maxilla extending to the basi-sphenoid. Its computed tomography (CT) and magnetic resonance imaging (MRI) and histopathological features and the management are presented. We also reviewed the literature of reported cases involving the maxilla.

Parapharyngeal space mesenchymal chondrosarcoma in childhood

A case of extra osseous mesenchymal chondrosarcoma occuring in the parapharyngeal space in a 7-year-old girl, is being presented for its rarity. It is a slow growing, locally aggressive tumour with a high incidence of local recurrence as well as distant metastasis. It is rare in the pediatric age group and rarer in the parapharyngeal space. It has a poor prognosis, the 5-year survival rate varies between 30 and 50%. Radical surgery is the treatment of choice. Radiotherapy and chemotherapy have an adjuvant role. More experience with this tumour is required to evaluate the most effective treatment. Current literature on this subject has been reviewed.

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.

Mesenchymal chondrosarcoma with secondary orbital invasion

Orbital involvement with mesenchymal chondrosarcoma is rare. Until recently, despite the young age of the affected population, exenteration was the recommended management. We report a patient with orbital invasion by mesenchymal chondrosarcoma managed surgically without exenteration. Adjuvant chemotherapy and radiotherapy were administered. There is no evidence of local or distant tumor recurrence with 30 months of postoperative follow-up. This and other recent case reports suggest that exenteration may not be necessary for local tumor control of mesenchymal chondrosarcoma in the orbit.

Mesenchymal chondrosarcoma of the maxilla

We report, to our knowledge, the 10th recorded case of mesenchymal chondrosarcoma (MC) occurring in the maxilla. Our case is the youngest person reported with a tumour in this location. The prognosis for cure is poor with a high incidence of local recurrence as well as metastases. Treatment is based on radical surgery. Radiotherapy and chemotherapy have a adjuvant role but additional experience with this tumour is required to define the most efficacious treatment.