Dedifferentiated chondrosarcoma of the rib with a malignant mesenchymomatous component: an autopsy case report

Establishment and characterization of NCC-LMS3-C1: a novel patient-derived cell line of leiomyosarcoma

Leiomyosarcoma (LMS) is an aggressive mesenchymal malignancy, which originates from the smooth muscle cells or from the precursor mesenchymal stem cells that potentially differentiate into smooth muscle cells. LMS is one of the most common sarcomas. LMS has genomic instability, reflecting complex and unbalanced karyotypes, and the cytogenetic and molecular changes in LMS are not consistent. The standard treatment of the primary LMS is complete resection, and the metastasis is often observed even after curative surgery. Patient-derived cancer models are a key bioresource to develop a novel therapy, and we aimed to establish and characterize a novel cell line for LMS. We established a cell line from tumor tissues of the patient with LMS and named it NCC-LMS3-C1. We maintained NCC-LMS3-C1 cells for 12 months and passed them more than 30 times. Genome-wide copy number analysis demonstrated that NCC-LMS3-C1 cells harbored genetic abnormalities. NCC-LMS3-C1 cells exhibited aggressive phenotypes such as continuous growth, spheroid formation, and invasion in the tissue culture condition, which may reflect the clinical behaviors of LMS. We performed a drug screening using NCC-LMS3-C1 cells and found that four anti-cancer agents, such as bortezomib, dasatinib, mitoxantrone, and romidepsin, had remarkable anti-proliferative effects on NCC-LMS3-C1 cells. We conclude that NCC-LMS3-C1 cells will be a useful resource for the study of LMS.

Establishment and characterization of NCC-LMS2-C1-a novel patient-derived cancer cell line of leiomyosarcoma

Leiomyosarcoma (LMS) is a rare and aggressive mesenchymal malignancy, derived from smooth muscle cells or precursor mesenchymal stem cells for this tissue type. LMS has highly complex and unstable karyotypes, and the clinical outcomes in patients with LMS remain dismal as evidenced by the 5-year-survival of 64%. Novel therapeutic approaches are required to improve its clinical outcomes. Patient-derived cancer cell lines are indispensable as a tool to study the molecular mechanisms underlying clinical behaviors of tumor cells such as resistance to treatments, metastasis, and recurrence. However, only a limited number of LMS cell lines are publicly available, probably because of the rarity of patients with LMS, and a paucity of cell lines hinders the research on LMS. This study aimed to develop a patient-derived LMS cell line. We successfully established a cell line from the primary tumor tissue of a 90-year-old female patient with pleomorphic LMS, which we named NCC-LMS2-C1. NCC-LMS2-C1 cells were maintained as a monolayer culture for over 29 passages spanning 10 months. NCC-LMS2-C1 cells exhibited continuous growth, the ability to form spheroid, and invasion capability. We screened 213 anti-cancer drugs to find those that have anti-proliferation effects on NCC-LMS2-C1 cells, and identified a histone deacetylase inhibitor, romidepsin. In conclusion, we have established a novel LMS cell line, NCC-LMS2-C1, which will be a useful resource to study the mechanisms of LMS progression and perform high-throughput screening for anti-cancer drug discovery.

H3K27me3 deficiency defines a subset of dedifferentiated chondrosarcomas with characteristic clinicopathological features

Dedifferentiated chondrosarcoma is a rare bone sarcoma, whose genetic background remains incompletely understood. Mutations in SUZ12 or EED, which encode polycomb repressive complex 2 (PRC2) components, and resulting deficiency in H3K27me3 are characteristic features of the majority of malignant peripheral nerve sheath tumors. Here, we investigated H3K27me3 and PRC2 status in dedifferentiated chondrosarcoma. Among 19 evaluable dedifferentiated chondrosarcoma cases, six (32%) showed immunohistochemical loss of H3K27me3 only in the dedifferentiated component, whereas the well-differentiated component retained H3K27me3. H3K27me3-deficient dedifferentiated chondrosarcoma occurred in two men and four women with a median age of 66. All of these tumors affected bones of the upper half of the body, with the ribs being preferentially involved, which represented a significantly different distribution compared to that in the 13 H3K27me3-intact dedifferentiated chondrosarcomas. H3K27me3-deficient dedifferentiated chondrosarcomas were histologically different from H3K27me3-intact dedifferentiated chondrosarcomas, as the former invariably demonstrated dedifferentiated histology with a striking similarity to classic malignant peripheral nerve sheath tumor, comprising sweeping to swirling fascicles of relatively uniform spindle cells. Heterologous rhabdomyoblastic differentiation, the focal presence of grade 3 chondrosarcoma histology, and a cartilaginous component in the metastatic sites were exclusively seen in some cases of H3K27me3-deficient dedifferentiated chondrosarcoma. In all three H3K27me3-deficient dedifferentiated chondrosarcomas that contained focal grade 3 histology, dedifferentiated components did not juxtapose to the grade 3 areas but transitioned abruptly from the grade 1-2 components. Targeted next generation sequencing, which was successfully performed on four H3K27me3-deficient dedifferentiated chondrosarcomas, identified an IDH2 mutation in one case and COL2A1 truncations in three cases. The dedifferentiated areas of three cases harbored SUZ12 or EED alterations, which were absent in the well-differentiated component, suggesting a role for PRC2 aberrations in dedifferentiation. H3K27me3 deficiency defines a novel subset of dedifferentiated chondrosarcoma that requires recognition because of its diagnostic and potential clinical implications.

Dedifferentiated chondrosarcoma of the rib masquerading as a giant chest wall tumor in a teenage girl: an unusual presentation

Chondrosarcoma of the chest wall is a rare primary neoplasm found to occur in elderly men. Patients present with an enlarging, painful, anterior chest wall mass arising from either the vicinity of the costochondral junction or the sternum. Treatment includes wide resection with appropriate chest wall reconstruction. We report an unusual presentation of this uncommon tumor occurring as a huge chest wall mass in a young teenage girl.

Coronary artery bypass grafting and concomitant excision of chest wall chondrosarcoma

Coexistence of coronary artery disease and cancer with both requiring surgical treatment at the same time is rare. A 52 year male undergoing elective coronary artery bypass grafting was incidentally discovered to have a large soft tissue mass of variable consistency with cartilaginous elements arising from the right costal margin and adjoining ribs by a broad attachment and protruding into right pleural cavity. Frozen section suggested it to be either a chondrosarcoma or a teratoma. A wide excision of the mass with the adjoining muscle and periosteum along with quadruple coronary artery bypass grafting was done. This report is unusual on account of a) being the first reported case in world literature of concomitant excision of chondrosarcoma and coronary artery bypass grafting and b) the conservative management of the incidentally discovered chondrosarcoma by wide excision rather than chest wall resection with no local recurrence to date. Pathology of chondrosarcoma, in particular, and various management strategies when coronary artery disease and cancer coexist, in general, is discussed.

Dedifferentiated chondrosarcoma arising in a solitary osteochondroma with leiomyosarcomatous component: a case report

BACKGROUND

A rare variant of dedifferentiated chondrosarcoma with leiomyosarcomatous component in a 63-year-old male is reported.

CASE REPORT

He had a life-long osteochondroma adjacent to the left knee and recently developed swollen and pain. We initially suspected an intermediate grade chondrosarcoma arising in a solitary osteochondroma, but a biopsy specimen revealed a dedifferentiated component that histologically was classified as leiomyosarcoma. Multiple lung metastases were also present. The patient underwent amputation above knee and lung operation following adjuvant chemotherapy, but he died because of pulmonary metastasis 2 years after first admission.

DISCUSSION

The differentiated component usually shows the histological features of osteosarcoma, malignant fibrous histiocytoma, and fibrosarcoma. Among the rare dedifferentiation with leiomyosarcomatous component, case arising in a solitary osteochondroma is not reported yet.

Dedifferentiated parosteal osteosarcoma with well-differentiated metastases

Metastases of dedifferentiated sarcoma usually contain a dedifferentiated component. We report a rare case of dedifferentiated parosteal osteosarcoma (dd-POS) with well-differentiated multiple metastases in a 65-year-old woman with a painful firm mass on her thigh. Radiological examination revealed that the mass arose from the surface of her femur without medullary involvement. Multiple intramuscular metastases were detected in her lower leg on MR imaging. Small subcutaneous palpable masses were identified on her left lower leg, buttock, chest wall and head. An open biopsy and above-the-knee amputation were performed, and the mass on her femur was diagnosed as a dd-POS. However, histological examination on the subcutaneous lesions in her lower leg, buttock and head showed low-grade conventional POS without dedifferentiated components. To the best of our knowledge, this is the first report of a dd-POS with multiple metastases that do not contain any dedifferentiated components.

Well-differentiated chondrosarcoma of the humerus with prominent granular cell component: a hitherto unreported occurrence

We report the case of a well-differentiated chondrosarcoma of the proximal humerus in a 60-year-old man that featured a prominent component of granular cells, the granules being shown by electron microscopy to be lysosomal. Although secondary granular cell changes have been described in a large variety of tumor types, this is, to the best of our knowledge, the first documentation of this phenomenon in a skeletal chondrosarcoma.

Primary bone carcinosarcoma: Chondrosarcoma and squamous cell carcinoma with keratin pearl formation

Malignant bone tumors with epithelial differentiation are extremely rare. Only one case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma has ever been reported. Reported herein is a case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma, so-called carcinosarcoma of bone, arising in the femur of a 53-year-old man. The tumor was located within the femur and was diagnosed by curettage as a well-differentiated chondrosarcoma. No primary tumor was detected in any other organ. Within a few months the tumor had rapidly grown toward the soft tissue, and hemipelvectomy was performed. Examination of the surgical specimen revealed that the tumor was mainly composed of undifferentiated spindle sarcoma cells with scattered foci of chondrosarcoma and of squamous cell carcinoma with keratin pearl formation. The patient died approximately 6 months postoperatively. At autopsy multiple metastases were detected in the heart, both lungs, muscles, and lymph nodes. Interestingly, the chondrosarcoma and squamous cell carcinoma components were observed in several metastatic foci. The tumors in both the previously reported case and the present case contained components of chondrosarcoma and squamous cell carcinoma with keratin pearl formation, and this combination of histological features may be a unique characteristic of carcinosarcoma of bone.

Ring chromosomes in a malignant mesenchymoma

We report, for the first time, the cytogenetic and molecular genetic constitution of a human mesenchymoma. As in several other soft tissue sarcomas, supernumerary ring and rod-shaped marker chromosomes were observed next to an otherwise normal diploid karyotype. Comparative genomic in situ hybridization and whole chromosome painting experiments revealed that chromosome 1q21-q25 and 12q14-q15 sequences were amplified, and that these sequences resided on the supernumerary marker chromosomes. We assume that, in this malignant mesenchymoma, the observed chromosomal anomalies may be associated with its well differentiated liposarcomatous component.