Thoracic Spinal Cord Primary Mesenchymal Chondrosarcoma. Case Report

Case Report

Austin J Clin Case Rep. 2024; 11(1): 1314.

Thoracic Spinal Cord Primary Mesenchymal Chondrosarcoma. Case Report

Martha Lilia Tena-Suck1; Nora Kerik2; Oriana Carolina García-Diaz3; Ivan Eudaldo Diaz Meneses2; Juan Salvador Rosales García2; Samuel Ismael Juárez Cruz1; Nicasio Arriaga4

1Department of Neuropathology, National Institute of Neurology and Neurosurgery, Mexico

2Molecular Imaging Unit PET-CT, National Institute of Neurology and Neurosurgery, Mexico

3Hospital General Secretaria de Salud 450 Durango, Durando

4Department of Neuropathology, Service of Spinal Neurosurgery, National Institute of Neurology and Neurosurgery, Mexico

*Corresponding author: Martha Lilia Tena-Suck, MD Department of Neuropathology, National Institute of Neurology and Neurosurgery, México City, Av. Insurgentes sur no 3877, Colonia la joya, Delegación Tlalpan, Cuidad de México. Email: mltenasuck@gmail.com

Received: February 02, 2024 Accepted: March 13, 2024 Published: March 20, 2024

Abstract

Background: Mesenchymal chondrosarcoma is a rare, high-grade malignancy of bone or soft tissue with a unique biphasic histology and worse prognosis. It rarely occurs in the spinal region.

Clinical Case: We present the case of a 21-year-old woman who became pregnant and began with feeling of heavy legs and decreased strength. who progressively over a week was unable to walk, was scheduled for cesarean section and the patient showed complete loss of sensation, and urinary incontinence. Spinal TAC and PET showed a destructive tumor in T11-L1. She underwent laminectomy and a biphasic lesion was identified, that forming by a component of small round, blue cells, hyper vascularized with nests of cartilage interspersed between these cells. By immunohistochemistry it was positive for CD99, vimentin, focally for-s1-00 and IDH1 in the round cells and in the periphery of the cartilaginous areas. Weak synaptophysin immunoexpression and higher Ki67 and p53 li. Among the differential diagnoses were Edwing sarcoma, medulloblastoma, and small cell osteosarcoma.

Discussion: The origin of this tumor and especially the biphasic component are discussed. That could correspond to a tumor of immature cells of the stem cell type with different chondromatous maturation processes.

Keywords: Mesenchymal chondrosarcoma; Spinal chondrosarcoma; Spinal tumors; Immunohistochemistry; Positron Emission Tomography (PET).

Abbreviations: MCS: Mesenchymal Chondrosarcoma; WHO: World Health Organization; STT: Soft Tissue Tumors; CBTs: Bone Classifies Chondrogenic Bone Tumors; ACTs: Atypical Cartilaginous Tumors; CS: Chondrosarcoma; IDH1 and IDH2: Isocitrate Dehydrogenase 1 and 2 Mutations; ECM: Eosinophilic Chondroid Matrix; EMCS: Extraskeletal Mesenchymal Chondrosarcoma; EMA: Epithelial Membrane Antigen; PET: Positron Emission Tomography

Background

Chondrosarcoma (CS) is a malignant cartilaginous tumor that can be histologically categorized into 3 types: mesenchymal, classic, and myxoid [1]. In conclusion, the 2020 World Health Organization (WHO) classification classifies chondrosarcomas into eight subtypes: central conventional (grade 1 vs. 2–3), secondary peripheral (grade 1 vs. 2–3), periosteal, dedifferentiated, mesenchymal, and clear cell [2]. Intracranial MSCs can be characterized into 3 grades: Grade 1 (well differentiated), Grade 2 (moderately differentiated), and Grade 3 (poorly differentiated). Several subtypes exist that fluctuate in MCS [1-4], it is a rare soft tissue tumor arising from soft tissues, further most commonly originating in the bone, in extraskeletal sites has also been presented [2,3,5].

MCS is a well-defined tumor entity first described in 1959 by Lichtenstein and Bernstein [6] and Dahlin and Henderson [7]; in 1962 described 9 cases from the files of the Mayo Clinic.

MCS occurring principally of the lower extremities, meninges, and orbits, has a slight predominance in females with a general poor prognosis, and affects all ages, with greater frequency in the second decade of life [3], and has a variable clinical course with frequent recurrences and occasional distant osseous and visceral metastatic spread [1]. MCS is a rare malignant variant of chondrosarcoma whose incidence accounts for 0.2–0.7% of all malignant bone tumors or 3–10% of CS [3,4]. They are usually bone tumors but can be detected in the extra-skeletal sites. Extra-skeletal MCSs most often involve the brain and meninges, occasionally the intraspinal region [1]. Young adults are more susceptible to developing Extraskeletal Mesenchymal Chondrosarcoma (EMCS), MCS is generally grossly lobulated, firm, with ossified or cartilaginous elements, and often hypervascularity. MCS is morphologically categorized by a biphasic pattern of small round cells and islands of well-differentiated hyaline cartilage and composed of an admixture of undifferentiated mesenchymal cell cartilage [2-4].

Histopathological shows that the tumor is composed of spindle and round cells with a high nucleocytoplasmic ratio accompanied by scattered eosinophilic chondroid matrix or nest of cartilage [1-4].

MCS molecular features are similar to is a totally different pathological than the conventional Chondrosarcoma, this entity exhibiting complex cytogenetic alterations. HEY1-NCOA2 (8;8) (q21; q13) fusion is most described in MCS [4]. Other genes implicated have been IRF2BP2 gene and the transcription factor CDX1 gene [5].

The aim of this case reports a rare case of Mesenchymal chondrosarcoma origin in thoracic spinal cord in a 38 years old-man with weak IDH1 immunoexpression.

Clinical Case

We present the case of a 21-year-old woman who became pregnant and began with heavy legs and decreased strength, which progressively, over a week, was unable to walk. She was scheduled for cesarean section and the patient showed with hypoesthesia in the legs, complete loss of sensation and complete inability to walk and without strength with urinary incontinence. Acute myelitis was diagnosed, to the admission to our institution. The cerebrospinal fluid showed pleocytosis, and an MRI and PET analysis showed a lesion at T11-L1 (Figure 1). Positron Emission Tomography (PET) with Fluoro desoxiglucose 18FDG (10 Mci) whole body and brain scan were performed a (Figure 4) at 60 minutes post radiotracer administration, the scan was obtained on the ™ Biograph 64 mCT (Siemens Healthcare Molecular Imaging) hybrid device [12]. The images were reconstructed using the iterative method UltraHD PET (Siemens ™), obtaining a clinical spatial resolution of 4 mm. The images were visualized in a multimodal medical-grade workstation equipped with SYNGO software (Siemens ™) and qualitatively analyzed by two nuclear medicine physicians. Which showed: Ovoid, hyperdense lesion, with heterogeneous density at the expense of some calcifications, dependent on the T12 nerve root, protruding through the foramen at this level with approximate measurements of 20x15x20 mm which contacts the dura mater, reaching the adjacent paravertebral region, with an increase in SUVmax metabolism of 7.2. There were no other relevant morphological findings in the oncological clinical context.