Malignant proliferative ependymoma of the neck with lymph node metastasis: A case report.

BACKGROUND: Malignant proliferating trichilemmal tumor (MPTT) is an infrequent malignant neoplasm originating from cutaneous appendages, with only a handful of documented cases. This report delineates a unique instance of MPTT situated in the neck, accompanied by lymph node metastasis. A comprehensive exposition of its clinical trajectory and imaging manifestation is presented, aiming to enhance comprehension and management of this atypical ailment. CASE SUMMARY: Patient concerns: A 79-year-old male presented with a longstanding right neck mass persisting for over six decades, exhibiting recent enlargement over the past year. Diagnoses: Enhanced magnetic resonance imaging of the neck unveiled an elliptical mass on the right neck side, characterized by an ill-defined border and a heterogeneous signal pattern. The mass exhibited subdued signal intensity on T1-weighted imaging (T1WI) and a heterogeneous high signal on T2-weighted imaging (T2WI), interspersed with a lengthy T1 and T2 cystic signal motif. Close anatomical association with the submandibular gland joint was noted, and intravenous gadolinium diethylene triamine pentaacetic acid administration facilitated conspicuous enhancement. Substantial enhancement of the solid segment prompted an initial preoperative diagnosis of malignant nerve sheath tumor. However, post-surgery histopathological and immunohistochemical analysis conclusively confirmed the diagnosis as malignant hyperplastic external hair root sheath tumor. Intervention: Complete excision of the tumor was successfully executed. Outcomes: The patient experienced a favorable postoperative recovery. CONCLUSION: Malignant proliferative trichilemmal tumor external hair root sheath tumor is a cystic-solid lesion, appearing as low signal on T1WI images or high signal on T2WI with enhancement of the solid component. Suspicions of malignancy are heightened when the tumor border is indistinct, tissue planes are breached, or when linear or patchy high signals are observed in the subcutaneous tissue on T1 liver acquisition with volume acceleration enhanced images along with intermediate signal on T2WI and restricted diffusion on diffusion-weighted imaging images. Strong consideration for malignancy should arise if there are signs of compromised adjacent tissue relationships or direct invasion evident on imaging. We have incorporated the above-mentioned content into the entire manuscript.

Morphological evaluation of temporomandibular joint after open and closed treatment of type B diacapsular condylar fractures in sheep.

The incidence of diacapsular fracture of the mandibular condyle (DFMC) has increased in recent years. However, the specific modality of treatment which would provide maximum benefit and good results for adult patients of DFMC has been controversial. To evaluate and compare morphological changes of temporomandibular joint (TMJ) after open and closed treatments for DFMC, a sheep model of a type B DFMC was created by osteotomy. Eight sheep models of type B DFMC were randomly divided into 2 groups to receive closed treatment (Group 1) and open reduction and internal fixation (ORIF, Group 2), respectively, and morphological changes of TMJ were scored according to the radiological and anatomical criteria of scoring and compared between the 2 groups. Compared with Group 1 animals treated by the closed method, Group 2 animals treated with ORIF received significantly lower scores for morphological changes 12 weeks after treatment. We conclude that ORIF is more efficient than the closed functional treatment in restoring morphology of TMJ to treat type B DFMC.

[A histological study of three-dimensional external zygomatic suture distraction osteogenesis].

OBJECTIVE: To explore the histological change in suture of zygomatic bone for the zygomatic suture direct distraction osteogenesis. METHODS: The zygomatic bone was distracted by 3-D external distraction appliance without osteotomy. The specimens were taken 1, 3, 5 and 8 weeks after, and then examined histologically and compared with the blank contralateral side. RESULTS: There were lots of fibroblasts, osteoblasts and capillary vessels in the distracted suture tissues one week after distraction, and the fibers were observed to connect the sides of suture and arranged orderly. The surfaces of the expanded suture were irregular. Bone formation was active in the expanded side. The bone trabeculae were mature and oriented in the direction of distraction in the distracted sides at 3 weeks. A great amount of new woven bones were found in 5-week specimen. New bones were formed completely 8 weeks after the distraction. CONCLUSIONS: New bone formed rapidly in the distracted side of zygomatic bone under suture distraction osteogenesis without osteotomy.

[Reconstruction [correction to Reconstrction] of mandibular bone defects by using the techniques [correction to teachniques] of the reverse engineering and rapid prototyping].

OBJECTIVE: To evaluate the feasibility of designing and fabricating customized titanium bone substitutes to restore mandibular bone defects using reverse engineering (RE) and rapid prototyping (RP) techniques. METHODS: Titanium tray for mandibular defects were designed and fabricated through multi-step procedures of reverse engineering and rapid prototyping, then in operation it was filled with cancellous bone and fixed. RESULTS: The bone substitutes fabricated by this method had been successfully put into clinical use for maxillofacial surgery in 2 patients and got a satisfactory result. CONCLUSIONS: Reverse engineering combining with rapid prototyping could accomplish the design and manufacture of implant for the restoration of mandibular bone defects.

[Effects of aminoguanidine on the expression of NOS in facial nerve and surrounding tissues of traumatic facial paralysis rats].

OBJECTIVE: To study the effects of inducible NOS inhibitor aminoguanidine on the expression of NOS in facial nerve and surrounding tissue of traumatic facial paralysis rats. METHODS: A small dose of aminoguanidine were intraperitoneally injected into rats before and after facial paralysis. The facial nerve and surrounding tissues were cut at different time point. Immunohistochemical ABC method was used to study the changes of NOS expression in facial nerve and surrounding tissues. RESULTS: The inducible NOS immunoreactivity was obvious inhibited in the facial nerve and surrounding tissues in aminoguanidine group. CONCLUSION: Aminoguanidine chronic treatment can obvious inhibit the inducible NOS expression in the facial nerve and surrounding tissues. Aminoguanidine can improve the regeneration of facial nerve and the recovery of traumatic tissues.

[An experimental study of 3-dimension zygomatic suture extension for suture osteogenesis].

OBJECTIVE: To explore a methods of 3-Dimension expansion of zygomatic suture in a goat model. METHODS: Seven goats were used in this study. The 3-D extensive applicator was designed and used to extend the zygomatic suture of the goats by placing it in the zygomatic bone through an infraorbital incision. Ten days after the first operation, it was gradually extended on a speed of 0.09 cm/d for 7 days. The zygomatic movement and the osteogenesis of the suture was evaluated in two weeks. RESULTS: The zygomatic bone was extended for 0.6 cm long in average, and the osteogenesis was also shown significantly in the suture. CONCLUSION: The above mentioned technique could be a safe and effect method to be applied for the zygomatic extension.

Effect of recombinant human basic fibroblast growth factor on angiogenesis during mandible fracture healing in rabbits.

OBJECTIVE: To investigate the effect of recombinant human basic fibroblast growth factor (rhbFGF) on angiogenesis during mandible fracture healing in rabbit. METHODS: Fifty adult white rabbits were used for animal model and randomly divided into a control group (25 rabbits) and an experimental group (25 rabbits). The membranous complex of rhbFGF and bovine type I collagen was prepared and implanted into the rabbit mandible fracture site under periosteum. The animals were sacrificed on 7, 14, 28, 56 and 84 days respectively after operation and the whole mandibles were harvested. The expression of factor VIII related antigen (F8-RA) in callus was examined with immunohistochemical staining. RESULTS: The amounts of microvascular formation in calluses in the rhbFGF-treating group on days 7, 14, 28 and 56 were more than those of the control group (P<0.01). CONCLUSIONS: The results indicated that rhbFGF could stimulate microvascular formation during mandible fracture healing in rabbits.

[Effects of L-nitroarginine on the recovery of traumatic facial paralysis].

OBJECTIVE: To study the effects of constitutive nitric oxide synthase inhibitor L-nitroarginine on the recovery of traumatic facial paralysis in rats and the changes of the expression of cNOS and OX42 in the facial nucleus. METHODS: L-nitroarginine was intraperitoneally injected into rats and the recovery of facial paralysis was observed at different time point. and the changes of cNOS and OX42 positive neurons were studied in facial nucleus. RESULTS: Treatment of L-nitroarginine could remarkably inhibit the recovery of traumatic facial paralysis. The cNOS immunoactivity was obvious inhibited in facial nucleus, while the OX42 immunoactivity was obvious increased. CONCLUSION: Endogenous nitric oxide may play an important mediator role on the recovery of traumatic facial paralysis.

[A histologic observation of bone formation induced by subperiosteal implantation of resorbable porous block beta-tricalcium phosphate on calvarial surface in rabbits].

OBJECTIVE: By the histologic observation of samples, understanding the osteoconductive histologic behaviour and resorbable mechanism of beta-tricalcium phosphate (beta-TCP). METHODS: Porous block beta-TCP samples were implanted into calvarial surface. Tissue slices dyed with methods of HE and Masson's were observed by microscope and compared with hydroxyapatite(HA). RESULTS: Beta-TCP had the osteoconductivity,as well as HA, plentiful new bone penetrated into materials from the calvarial surface. There was no new bone under the periost obviously. A large number of rhagiorine cells swallowing beta-TCP had been observed. CONCLUSION: Beta-TCP has osteoconductivity, can be used as a substitution for atrophic alveolar ridge augmentation. The function of rhagiorine cell swallowing beta-TCP is the essential resorbable mechanism of beta-TCP.