The surgical pathology of notochordal remnants in adult intervertebral disks: a report of 3 cases

The notochord plays a critical role in organizing and directing vertebral development. In humans, most notochordal cells are eventually sequestered into the nucleus pulposus and disappear within the first decade of life. Although notochordal remnants and related lesions have been described in the axial skeleton of adults, their presence in intervertebral disks is rare. We describe herein 3 cases of incidental notochordal remnants identified in surgically removed adult intervertebral disks. Their histologic features were reminiscent of notochordal vestiges in the fetus. However, they raised the differential diagnosis of benign notochordal cell tumor and chordoma. Notochordal rests can be a source of diagnostic confusion and should be distinguished from notochordal neoplasms because they do not necessitate resection or other forms of therapy.     

Immunohistochemical identification of notochordal markers in cells in the aging human lumbar intervertebral disc

The fate of notochord cells during disc development and aging is still a subject of debate. Cells with the typical notochordal morphology disappear from the disc within the first decade of life. However, the pure morphologic differentiation of notochordal from non-notochordal disc cells can be difficult, prompting the use of cellular markers. Previous reports on these notochordal cell markers only explored the occurrence in young age groups without considering changes during disc degeneration. The aim of this study, therefore, was to investigate presence, localization, and abundance of cells expressing notochordal cell markers in human lumbar discs during disc development and degeneration. Based on pilot studies, cytokeratins CK-8, -18 and -19 as well as Galectin-3 were chosen from a broad panel of potential notochordal cell markers and used for immunohistochemical staining of 30 human lumbar autopsy samples (0–86 years) and 38 human surgical disc samples (26–69 years). In the autopsy group, 80% of fetal to adolescent discs (0–17 years) and 100% of young adult discs (18–30 years) contained many cells with positive labeling. These cells were strongly clustered and nearly exclusively located in areas with granular changes (or other matrix defects), showing predominantly a chondrocytic morphology as well as (in a much lesser extent) a fibrocytic phenotype. In mature discs (31–60 years) and elderly discs (≥60 years) only 25 and 22–33%, respectively, contained few stained nuclear cells, mostly associated with matrix defects. In the surgical group, only 16% of samples from young adults (≤47 years) exhibited positively labeled cells whereas mature to old surgical discs (>47 years) contained no labeled cells. This is the first study describing the presence and temporo-spatial localization of cells expressing notochordal cell markers in human lumbar intervertebral discs of all ages and variable degree of disc degeneration. Our findings indicate that cells with a (immunohistochemically) notochord-like phenotype are present in a considerable fraction of adult lumbar intervertebral discs. The presence of these cells is associated with distinct features of (early) age-related disc degeneration, particularly with granular matrix changes.     

A histopathological study on the intervertebral discs of idiopathic and paralytic scoliosis--abnormalities in transition from the notochordal nucleus to the fibrocartilaginous nucleus

To elucidate morphologic events, 105 intervertebral discs in 22 patients with idiopathic scoliosis and 14 in four patients with paralytic scoliosis were histopathologically compared with 13 control intervertebral discs in 13 cases, including three fetuses. In control intervertebral discs, the notochordal area became smaller with age, and was almost completely occupied by fibrocartilagenous matrix at 16 years of age or more. In intervertebral discs of patients aged 19-33 with idiopathic scoliosis, many notochordal cells were seen and many areas without fibrocartilagenous matrix were found. In contrast, in intervertebral discs of patients aged 21-35 with paralytic scoliosis, there was no notochordal cells or defect of the fibrocartilagenous matrix. The results suggest an impairment of transition from the notochordal nucleus to the fibrocartilagenous nucleus in intervertebral discs in patients with idiopathic scoliosis, and that such abnormalities are related to the onset of idiopathic scoliosis.     

Granular cell tumors of the extremities

Granular cell tumors are uncommon tumors that may arise from various soft tissue and visceral sites. These lesions often are multifocal but, with rare exceptions, are benign. Much of the literature on granular cell tumors is based on case reports mostly in the otolaryngology literature, and most series are limited to histopathologic studies. There are no documented series of cases in the orthopaedic literature. Granular cell tumors do occur in the extremities; thus, patients with a peripheral granular cell tumor may be referred to an orthopaedist. Ten cases of benign granular cell tumor treated at the authors' institution between 1993 and 1999 are reported. Five tumors of the thigh and one tumor of the groin were treated with wide excision, whereas three tumors of the hand and one tumor of the elbow were treated with marginal resection. Although two tumors treated with attempted wide excision had positive margins, none of the tumors have recurred after an average followup of 27 months. The presentation, radiography, histologic findings, and treatment of benign granular cell tumors that distinguish it from other soft tissue lesions are discussed.     

Three types of spindle cell tumors of the pleura. Fibroma, sarcoma, and sarcomatoid mesothelioma

The clinicopathologic features of 17 fibrous tumors of the pleura are presented. Eight were benign localized fibrous tumors; all of these were negative when stained with antibodies to keratin. Eight were diffuse malignant tumors that demonstrated intense immunohistochemical staining of the spindle cells with antibodies to keratin. One case presented as a histologically malignant spindle cell tumor that was initially localized but recurred subpleurally three times in 12 years. This spindle cell tumor was consistently negative when stained for keratin. We conclude that there are three types of fibrous tumors of the pleura: (a) a localized, histologically benign, keratin-negative spindle cell tumor that might be termed "fibroma," (b) a diffuse, histologically malignant, keratin-positive neoplasm that might appropriately be termed a "sarcomatoid mesothelioma," and (c) a histologically malignant, keratin-negative, spindle cell tumor with the potential to spread under the pleura that might appropriately be termed a "sarcoma." Immunohistochemistry proved to be useful in distinguishing the sarcomatoid mesothelioma from the sarcoma.     

Primary tumors of the cervical spine: surgical experience with 38 cases.

Thirty-eight primary tumors of the cervical spine were operated on in the Section of Neurosurgery, Department of Neurological Sciences, "La Sapienza" University of Rome between 1954 and 1988. Of these, 23 were malignant and 15 benign. The aims of surgical treatment in every case were tumor removal, decompression of the spinal cord, and conservation or restoration of vertebral stability. In no case was surgery confined to biopsy. Surgical stabilization was performed in 12 patients. Bone fusion was obtained with autologous bone (iliac crest, fibula) in benign tumors, whereas synthetic material (acrylic and metal) was used in malignant tumors. Past experience and greater awareness of the concrete possibilities of treating these tumors have led us to evolve the following strategy: 1. For aggressive benign tumors (osteoblastoma, giant cell tumors) and for malignancies in patients with fair life expectancy (solitary myeloma, chordoma): radical removal. 2. For benign tumors with low neoplastic potential and for malignant tumors in patients with poor life expectancy: conservative removal. Long-term results were gratifying in all benign lesions and low-grade malignancies even though two patients with chordomas needed reoperations. Sarcomas had relatively poor results.     

A rat tail temporary static compression model reproduces different stages of intervertebral disc degeneration with decreased notochordal cell phenotype

The intervertebral disc nucleus pulposus (NP) has two phenotypically distinct cell types—notochordal cells (NCs) and non‐notochordal chondrocyte‐like cells. In human discs, NCs are lost during adolescence, which is also when discs begin to show degenerative signs. However, little evidence exists regarding the link between NC disappearance and the pathogenesis of disc degeneration. To clarify this, a rat tail disc degeneration model induced by static compression at 1.3 MPa for 0, 1, or 7 days was designed and assessed for up to 56 postoperative days. Radiography, MRI, and histomorphology showed degenerative disc findings in response to the compression period. Immunofluorescence displayed that the number of DAPI‐positive NP cells decreased with compression; particularly, the decrease was notable in larger, vacuolated, cytokeratin‐8‐ and galectin‐3‐co‐positive cells, identified as NCs. The proportion of TUNEL‐positive cells, which predominantly comprised non‐NCs, increased with compression. Quantitative PCR demonstrated isolated mRNA up‐regulation of ADAMTS‐5 in the 1‐day loaded group and MMP‐3 in the 7‐day loaded group. Aggrecan‐1 and collagen type 2α‐1 mRNA levels were down‐regulated in both groups. This rat tail temporary static compression model, which exhibits decreased NC phenotype, increased apoptotic cell death, and imbalanced catabolic and anabolic gene expression, reproduces different stages of intervertebral disc degeneration. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:455–463, 2014.     

Salivary gland-type tumors with myoepithelial differentiation arising in pulmonary hamartoma: report of 2 cases of a hitherto unrecognized association

Reported is a hitherto unrecognized association of pulmonary hamartomas with salivary gland-type tumors showing myoepithelial differentiation, namely, a case of myoepithelioma arising in a otherwise classic hamartoma with cartilage predominance, and a case of malignant mixed tumor arising in a predominantly fibrous hamartoma resembling müllerian adenofibroma. The tumors occurred in middle-aged female patients of 35 and 44 years, respectively, and presented as 7 cm (treated with lobectomy) and 13 cm (treated with pneumonectomy) masses of the right upper lobe showing a short clinical history of cough, dyspnea, and wheezing. Both lesions did not present regional lymph node metastases after mediastinal lymphadenectomy. The myoepithelioma patient was well with no signs of recurrent disease at 6-month clinical control, but she was then lost to follow-up; the malignant mixed tumor patient is alive and well after 6 months since operation. Both tumors presented with morphologic and immunohistochemical features of myoepithelial cells, and we interpret them as being derived from a myoepithelial-like stromal cell population found within the hamartomatous areas, which is also consistently detected in classic pulmonary hamartoma. The lack of individual cell necrosis, mitotic activity, cell atypia, and pulmonary parenchyma infiltration supported a diagnosis of benign or unproven malignant potential tumor for the myoepithelioma, whereas the reverse held true for the other tumor in which the diagnosis of malignant mixed tumor of the lung was rendered. Their main importance of recognizing this association lies in separating these tumors histologically from other monophasic or biphasic tumors, either primary or secondary, such as pulmonary sarcomatoid carcinomas or true sarcomas, and metastatic salivary gland tumors, spindle cell carcinomas, melanomas, and soft tissue and visceral sarcomas.     

Primary tumors of the spine. Initial oncologic aspects: epidemiology, anatomo-prognostic and therapeutic classification

Primary tumors of the vertebral column are rare: 20 per cent of all primary tumors of the spinal column. The distribution by type of tumor shows that the three most frequent primary tumors considered to be "radio and/or chemo resistant lesions" are the chordoma (15.5 to 24.5%), the chondrosarcoma (20%) and the giant cell tumor (10%). A second group with "chemo and/or radiosensitive lesions" include the Ewing sarcoma, primary lymphoma and plasmocytoma (5%). We consider a third group with the benign tumor: osteochondroma, chondroma, osteoid osteoma, osteoblastoma, aneurysmal bone cyst, hemangioma and eosinophilic granuloma (2 to 3%). The last tumoral group agrees with sarcomatous tumors: osteogenic sarcoma, fibrosarcoma, malignant fibro-histiocytoma, angiosarcoma and hemangio-pericytoma (1 to 3% of primary tumors of the vertebral column); they are most frequently secondary to Paget's disease, giant cell tumor or to radiation therapy and their prognosis is poor.     

Gutartige Knochentumoren

Background

Benign bone tumors and tumor-like lesions are much more frequent than malignant bone tumors among the total number of tumors of the skeleton.

Objective

This article gives a presentation of the characteristics and treatment modalities of benign bone tumors.

Material and methods

In this article in-house treatment principles are compared with those in the currently available literature.

Results

Benign bone tumors are frequently found incidentally; however, the term benign does not always signify that a purely observational role is needed. Benign bone tumors differ in their biological behavior and can be latent, active or aggressive which determines the treatment approach. Some benign bone tumors are just as aggressive locally as malignant tumors. The most important diagnostic feature is still conventional radiography and a thorough systematic analysis is necessary. Therapy options range from ignore, wait and see up to wide resection. In contrast to malignant tumors the radicalism of resection can be weighed against the accompanying local control and loss of function.

Conclusion

The treatment of benign bone tumors depends on the histological type and the biological activity. Most benign bone tumors are diagnosed incidentally and do not necessitate any treatment.     

兔脊索细胞体外培养及生物学特点观察

目的建立体外兔椎间盘脊索细胞藻酸盐凝胶培养模型,观察脊索细胞形态及生物学特点。方法采用胶原酶消化法及Percoll不连续密度梯度沉淀法体外分离收集原代椎间盘脊索细胞,于1.2%藻酸盐凝胶(低密度)中培养。倒置相差显微镜下观察细胞形态,经Ⅱ型胶原免疫荧光染色对细胞表型初步鉴定,并分别以细胞增殖和细胞毒性试剂-8(CCK-8)检测细胞在藻酸盐凝胶中的存活和增殖能力。结果成功分离获得原代椎间盘脊索细胞,可稳定表达Ⅱ型胶原。原代脊索细胞在藻酸盐凝胶中生长良好,但增殖缓慢。结论初步了解兔椎间盘脊索细胞体外生物学特性,为椎间盘退变机制及组织工程学髓核种子细胞的研究提供一定的实验依据。     

脊柱原发性肿瘤的切除方式与疗效分析

目的探讨脊柱原发性肿瘤分期指导切除方式的疗效。方法回顾性分析1997—2006年手术治疗的脊柱原发性肿瘤患者41例，男27例，女14例；年龄为1—71岁，平均30．5岁；良性23例（含嗜酸性肉芽肿11例），恶性18例（含骨巨细胞瘤7例）。结合Enneking和WBB分期分块切除肿瘤，椎体切除14例17个节段，后弓切除8例10个节段，全脊椎切除10例12个节段，其余类型11例。结果随访6—76个月，平均24个月。疼痛改善优良率97．6％。Frankel改善1级21例，改善2级7例，无改善13例。SF-36评分平均提高22．1。总复发率为12．2％（5／41），骨巨细胞瘤复发率为14．3％（1／7），恶性肿瘤复发率为36．4％（4／11）。结论Enneking和WBB分期指导脊柱原发性肿瘤手术，切除较彻底，近中期疗效良好，但仍存在缺陷，需进一步完善。SF-36可用于患者生命质量的全面评测。     

良性肝脏肿瘤肝移植相关进展

肝脏肿瘤分为良性和恶性,其中良性肝脏肿瘤较为常见,治疗以随访观察、介入治疗为主,仅少数情况下需要进行外科手术切除治疗。肝移植可有效治疗终末期肝病,但通常不作为良性肝脏肿瘤的治疗手段,仅存在巨大占位压迫、合并肝衰竭、肿瘤破裂出血风险或恶变风险的良性肝脏肿瘤才考虑进行肝移植治疗。与恶性肿瘤及慢性肝衰竭肝移植相比,良性肝脏肿瘤肝移植手术风险相当,预后及远期生存较为理想。但良性肝脏肿瘤肝移植术前应充分谨慎评估,同时注意新形势下供肝匹配难度。本文对良性肝脏肿瘤包括肝血管瘤、多囊肝、肝细胞腺瘤、肝脏间叶错构瘤等肝移植相关研究进展进行总结,旨在为肝移植治疗良性肝脏肿瘤提供参考。     

High glucose-induced oxidative stress promotes autophagy through mitochondrial damage in rat notochordal cells

Purpose

Diabetes mellitus is associated with an increased risk of intervertebral disc degeneration (IDD). Reactive oxygen species (ROS), oxidative stressors, play a key role in autophagy of diabetes-associated diseases. Mitochondria are known to be the main source of endogenous ROS in most mammalian cell types. The authors therefore conducted the following study to evaluate the effects of high glucose concentrations on the induction of oxidative stress and autophagy through mitochondrial damage in rat notochordal cells.

Methods

Rat notochordal cells were isolated, cultured, and placed in either 10 % fetal bovine serum (normal control) or 10 % fetal bovine serum plus two different high glucose concentrations (0.1 M and 0.2 M) (experimental conditions) for one and three days, respectively. We identified and quantified the mitochondrial damage (mitochondrial transmembrane potential) and the generation of ROS and antioxidants (manganese superoxide dismutase [MnSOD] and catalase). We also investigated expressions and activities of autophagy markers (beclin-1, light chain3-I [LC3-I] and LC3-II, autophagy-related gene [Atg] 3, 5, 7, and 12).

Results

An enhanced disruption of mitochondrial transmembrane potential, which indicates mitochondrial damage, was identified in rat notochordal cells treated with both high glucose concentrations. Both high glucose concentrations increased production of ROS by rat notochordal cells in a dose- and time-dependent manner. The two high glucose solutions also enhanced rat notochordal cells’ compensatory expressions of MnSOD and catalase in a dose- and time-dependent manner. The proautophagic effects of high glucose concentrations were manifested in the form of enhanced rat notochordal cells’ expressions of beclin-1, LC3-II, Atg3, 5, 7, and 12 in a dose- and time-dependent manner. The ratio of LC3-II/LC3-I expression was also increased in a dose- and time-dependent manner.

Conclusions

The findings from this study demonstrate that high glucose-induced oxidative stress promotes autophagy through mitochondrial damage of rat notochordal cells in a dose- and time-dependent manner. These results suggest that preventing the generation of oxidative stress might be a novel therapeutic target by which to prevent or to delay IDD in patients with diabetes mellitus.     

Viability,growth kinetics and stem cell markers of single and clustered cells in human intervertebral discs: implications for regenerative therapies

Purpose

There is much interest in the development of a cellular therapy for the repair or regeneration of degenerate intervertebral discs (IVDs) utilising autologous cells, with some trials already underway. Clusters of cells are commonly found in degenerate IVDs and are formed via cell proliferation, possibly as a repair response. We investigated whether these clusters may be more suitable as a source of cells for biological repair than the single cells in the IVD.

Methods

Discs were obtained at surgery from 95 patients and used to assess the cell viability, growth kinetics and stem or progenitor cell markers in both the single and clustered cell populations.

Results

Sixty-nine percent (±15) of cells in disc tissue were viable. The clustered cell population consistently proliferated more slowly in monolayer than single cells, although this difference was only significant at P0–1 and P3–4. Both populations exhibited progenitor or notochordal cell markers [chondroitin sulphate epitopes (3B3(?), 7D4, 4C3 and 6C3), Notch-1, cytokeratin 8 and 19] via immunohistochemical examination; stem cell markers assessed with flow cytometry (CD73, 90 and 105 positivity) were similar to those seen on bone marrow-derived mesenchymal stem cells.

Conclusions

These results confirm those of previous studies indicating that progenitor or stem cells reside in adult human intervertebral discs. However, although the cell clusters have arisen via proliferation, there appear to be no greater incidence of these progenitor cells within clusters compared to single cells. Rather, since they proliferate more slowly in vitro than the single cell population, it may be beneficial to avoid the use of clustered cells when sourcing autologous cells for regenerative therapies.     

Patellar tumors

Pain in the anterior knee has become synonymous with patella chondromalacia. However, pain also is the first sign of a tumor of the patella. Tumors of the patella are rare, but they often are mistaken for other benign lesions. Benign tumors of the patella are more frequent than malignant tumors (73% versus 27%). The most common benign neoplasms are giant cell tumor and chondroblastoma. Margin of the lesion, cortical involvement, trabecular pattern, and type of the matrix are important features for a radiographic diagnosis. Bone scans, computed tomography scans, and magnetic resonance images are used for staging of the tumor before surgery. Curettage only should be considered for patients with Stage 1 or Stage 2 benign lesions. Patellectomy is indicated for patients with Stage 3 aggressive benign tumors and for patients with Stage IA malignant tumors. A patellectomy with excision of involved soft tissues is used in patients with Stage IB tumors, whereas in patients with Stage IIA tumors, an extensive patellectomy is indicated. In patients with Stage IIB tumors, an extraarticular resection of the knee is preferred when there is a small soft tissue involvement, but amputation is necessary when there is a large soft tissue mass.     

Same-species phenotypic comparison of notochordal and mature nucleus pulposus cells

Purpose

The ratio of notochordal (NC) cells to mature nucleus pulposus (MNP) cells in the nucleus pulposus varies with species, age and health. Studies suggest that loss of NC cells is a key component of intervertebral disc degeneration. However, few studies have examined the phenotypes of these two cell populations. Therefore, this study aimed to isolate NC and MNP cells from the same intervertebral disc and study phenotypic differences in extracellular matrix production and cell morphology in 3D culture over 7 days.

Methods

Sequential mechanical dissociation and enzymatic digestion were used to isolate NC cell clusters and single MNP cells from bovine caudal discs. Cells were cultured in alginate beads and subsequently analysed for viability, cytokeratin-8 expression, GAG production and extracellular matrix gene expression.

Results

Mechanical dissociation allowed NC cells to be extracted as intact cell clusters. NC cells represented 8 % of the NP cell population and expressed both cytokeratin-8 and vimentin. MNP cells expressed vimentin, only. Both cells types were viable for 7 days. In addition to morphological differences, NC cells produced up to 30 times more total proteoglycan than MNP cells. NC cells had significantly higher aggrecan and brachyury expression.

Conclusions

NC and MNP cells can be isolated from the same bovine disc and maintain their distinct phenotypes in 3D culture.