Encapsulated Tumor Research Articles

Schwannoma Arising at Unusual Locations: A Report of 4 Cases

Neurilemmoma (schwannoma) is a benign, encapsulated perineural tumor of neuroectodermal derivation that originates from the Schwann cells of the neural sheath of motor and sensitive peripheral nerves. Schwannomas are commonly seen in the head and neck region, flexor surface of extremities. However, schwannoma can arise from any cranial or spinal nerve as a globoid encapsulated tumor. We report a case series of four cases of schwannoma arising from four unusual sites one presenting as a parotid tumor; second one as a pleural mass, third as parapharyngeal mass and the fourth one as a nasal mass.

Laryngeal schwannoma excised under a microlaryngoscope without tracheotomy: A case report

Schwannomas are benign encapsulated tumors arising from Schwann cells in the peripheral nervous system. Between 25 and 45% of schwannomas occur in the head and neck region. Schwannomas of the larynx are extremely rare with an incidence of 0.1–1.5% in all benign laryngeal tumors. Laryngeal schwannomas usually occur in females aged between their 4th and 5th decades. The most successful curative method is surgical resection. When selecting the surgical method, the size and location of the tumor, as well as the requests of the patient, should be considered. The present case report describes a 29-year-old female patient with symptoms of hoarseness and dyspnea on exertion. Through endoscopic biopsy, histopathology revealed a schwannoma. Considering the symptoms, age and preferences of the patient, the method of trans-oral microlaryngoscopic excision without tracheotomy was used to excise the tumor located in the aryepiglottic fold. Results from a short-term follow-up showed the postoperative result to be satisfactory.

‘Invasion of Meningioma Cell in Bony Hyperostosis- an Observational Study of 34 Cases’

Background: Meningiomas are usually globular encapsulated tumors. They are extra axial tumors attached to dura and compress the underlying brain without invading it. Abnormalities of bone are frequently encountered in Meningiomas. Hyperostosis or endosotsis are certainly more common than destruction of bone. Aims and Objective: Aim of study was to observe the percentage of tumour cell invasion in to the hyperostosis part of intracranial meningiomas. Materials and methods: This is an observational analytic study. Sample size was 34. Place of study was department of Neurosurgery of Square Hospitals Ltd. All the patients with the histological diagnosis of meningioma were included in to this study. Result: Female patients were predominant. Highest number of patients was from 41 to 50 years age group. Convexity meningiomas were commonest (35%) followed by parasagittal meningiomas. According to histopathological subtype meningothelimatous was commonest (56%) followed by psammomatous. About one fourth meningioma patients (26.47%) presented with hyperostosis. Among the hyperostosis patients in 44.44% patient’s cause of hyperostosis was due to tumour cell invasion into hyperostosis part. Conclusion: Tumour cell invasion is one of the causes of hyperostosis in intracranial meningiomas which was responsible in more than one third cases in this study. Bangladesh Journal of Neuroscience 2011; Vol. 27 (2) : 78-82 DOI: http://dx.doi.org/10.3329/bjn.v27i2.17573

Oral Schwannoma—An Unusual Oral Presentation: Case Report and Literature Review

Schwannoma or neurilemmoma is benign, slow growing, usually solitary and encapsulated tumor, originating from schwann cells of the nerve sheath. Intraoral schwannoma accounts for 1% of head and neck region and commonly involves tongue. Most of the earlier reports in the literature, have described schwannomas that occurred in the tongue. In this article, we report a case of schwannoma involving an unusual site mandibular labial vestibule, in a young patient. The lesion was completely excised with no reported complication for a followup of 15 months.

Neurilemmoma of the tongue: A case report

Neurilemmomas, also referred to as schwannomas or neurinomas, are benign encapsulated nerve sheath tumors composed of Schwann cells. Neurilemmomas arise when proliferating schwann cells form a tumor mass of unknown etiology encompassing motor and sensory peripheral nerves. We report a rare case of neurilemmoma over the ventral surface of the tongue. A 15-year-old child came to our Department of oral and maxillofacial surgery, Govt. Dental College, Kozhikode complains of swelling over ventral surface of tongue since two years. The lesion was freely moveable and asymptomatic. Clinically, the lesion appeared to be a benign soft tissue neoplasm. Excisional biopsy of the lesion was done under local anesthesia and tissue was sent for histopathological examination. Diagnosis is made by histological examination of the lesion. The treatment is surgical excision of the lesion. They do not show recurrence after complete excision. As neurilemmoma is a benign neoplasm, surgical excision is the treatment of choice. The prognosis of neurilemmoma is usually excellent after adequate excision. This case showed no recurrence after the treatment and malignant transformation of a previously benign neurilemmoma is exceedingly rare.

Imaging Features of Eyelid Pilomatraixoma

Pilomatrixoma is an uncommon benign tumor of matrix cells of hair follicles that rarely involves eyelids. Here we present a case of 4-year-old girl who was brought to hospital with swelling in the left upper eyelid which increased gradually in 1 year. Computed tomography revealed calcified soft tissue mass. The mass was excised successfully and sent for histopathological examination that showed encapsulated tumor composed of eosinophilic ghost cells and basophilic cells suggestive of pilomatrixoma.

English

Nerve sheath tumors arising from the cervical vagus nerve are extremely rare, and are of diagnostic challenge. We report A 14-year old male presented with swelling in the left side of neck for the past 6 months. FNAC revealed a vascular lesion, MRI scan showed a well circumscribed mass, 4 × 4 cm located in the lateral part of neck and was suggestive of a Glomus tumor. At surgery the swelling was found to be in close proximity with the internal jugular vein and common carotid artery and the vagus nerve on the left side. The encapsulated tumor was completely resected through a J-incision and it was found to be a benign schwannoma in pathology. Schwannoma are relatively rare tumor and even rarer in children. The incidence of such tumors and the management of our patients are discussed.

Oral angioleiomyoma: a case report and considerations on differential diagnosis

Angioleiomyomas are benign mesenchymal tumors derived from smooth muscle, which rarely occur in the oral cavity. We report a case of an angioleiomyoma occurring in the maxillary gingiva. The lesion was painless, with a lobulated surface, fibrous in consistency, and firm upon palpation. Microscopic examination showed an encapsulated tumor mass composed of large vascular channels of varying calibers, surrounded by thick walls of irregularly arranged, spindle-shaped cells, which were immunopositive for smooth-muscle actin. It is sometimes difficult to differentiate an angioleiomyoma from other spindle-cell tumors, thus we emphasize its histological differential diagnosis.

Imaging and surgical approach for a schwannoma of the hand.

Schwannomas are benign encapsulated neoplasms of the peripheral nerve sheath. Clinical diagnosis is often difficult, and final diagnosis is usually based on histopathological findings. Imaging techniques, such as magnetic resonance imaging and ultrasonography, can be optimized to improve assessment prior to surgical treatment. The present case demonstrates that high-resolution sonography can be useful in assessing the underlying cause of median nerve pathology.

Anticancer and immunostimulatory role of encapsulated tumor antigen containing cobalt oxide nanoparticles

The purpose of this study is to evaluate the prospect of using surface modified cobalt oxide(CoO) nanoparticles as carriers of cancerantigens to human macrophages. N-Phosnomethyliminodiacetic acid (PMIDA) was used for surface modification to overcome the toxic effect of CoO nanoparticles. Here, the phosphonate group of the PMIDA acts as a surface-anchoring agent and the remaining -COOH groups bind nonspecifically with tumor associated antigens. This modification allows the conjugation of human oral carcinoma (KB) cell lysate (CL) as an antigen with PMIDA coated CoO nanoparticles (CL-PMIDA-CoO). Particle characterization was performed by dynamic light scattering, atomic force microscopy, and scanning electron microscopy studies. Fourier transform IR spectroscopy was used to investigate conjugation of the protein with nanoparticles. Protein encapsulation was confirmed by protein gel electrophoresis. Active uptake of antigen-conjugated nanoparticles by macrophages was confirmed by fluorescence microscopy. The antitumor activity of the nanocomplex pulsed macrophages was investigated on a human oral carcinoma cell line (KB) in vitro. The modified nanocomplexes upregulate IFN-γ and TNF-α and induce an anticancer immune response by activating macrophages. The use of TNF-α inhibitor confirmed the ability of the CL-PMIDA-CoO nanocomplex to stimulate TNF-α mediated immunostimulation. CL-PMIDA-CoO nanoparticles efficiently increased the CD4(+) population. Thus, our findings provide insight into the use of PMIDA coated CoO nanoparticles as antigen delivery vehicles.

Lipomatous ganglioneuroma of the retroperitoneum

Lipomatous ganglioneuroma (LG) is a rare variant of ganglioneuroma that is histologically characterized by a mature adipocytic component admixed with a conventional ganglioneuroma. We report the clinicopathological and immunohistochemical features of an LG in a 44-year-old Chinese male; additionally, we review the literature regarding this type of tumor. Magnetic resonance imaging revealed a left paravertebral soft-tissue mass at the T11-L3 levels. Grossly, the encapsulated neoplasm had a white to yellowish cut surface and rubbery consistency. Microscopic evaluation revealed an encapsulated lesion that consisted of areas of ganglioneuroma admixed with areas of mature fat. By immunohistochemistry, the ganglion cells were positive for chromogranin and synaptophysin, whereas the Schwann cells were positive for vimentin, S-100 protein, and glial fibrillary acidic protein (GFAP). This is the second known report of a retroperitoneal LG. The patient was well and without evidence of disease at 2 years' follow-up.

English

INTRODUCTION: Ancient schwannomas are rare encapsulated tumours that derive from the nerve sheath and should be removed due to their infrequent but existent possibility of malignancy. CASE PRESENTATION: We report a case of a mass located in the L4 lumbar spine in a 50 year old woman who presented with low back ache since 6 months. Ultrasound, CT and MRI were used to examine the characteristics of the lesion. Fine needle aspiration showed cytological characteristics of a benign schwannoma and final histological diagnosis was an Ancient schwannoma. A posterior approach, through a left paraspinal incision was used to approach the site of the mass. The lesion originated from a branch of the L4 nerve root of the L4-L5 lumbar spinal space and a complete excision was achieved, preserving the nerve. CONCLUSION: Paraspinal tumours can be benign to most aggressive lesions. It is therefore a necessity for the surgeon to understand the pathology preoperatively by a MRI and FNAC, to avoid overtreatment and major complications.

Molecular Genotyping of Follicular Variant of Papillary Thyroid Carcinoma Correlates with Diagnostic Category of Fine-Needle Aspiration Cytology: Values of RAS Mutation Testing

The follicular variant of papillary thyroid carcinoma (FVPTC) presents distinct histologic subtypes and molecular genotyping. The preoperative diagnosis of FVPTC through fine-needle aspiration cytology (FNAC) is challenging. We reviewed 59 archival thyroid FNAC specimens of surgically confirmed FVPTC according to histologic subtype: encapsulated FVPTC (n = 30) and infiltrative FVPTC (n = 29). Galectin-3 immunostaining and molecular analyses for BRAF and three RAS genes (NRAS, HRAS, and KRAS) were performed. FNAC diagnoses of FVPTC included benign (5%), atypia of undetermined significance (19%), follicular neoplasm/suspicious for follicular neoplasm (14%), suspicious for PTC (29%), and PTC (34%). Galectin-3 immunostaining was positive in 50% of FNAC specimens. A BRAF mutation was found only in 14 (24%) tumors with the FNAC diagnosis of PTC or suspicious for PTC: 13 cases with the usual c.1799T>A (p.V600E) mutation and 1 case with a 3 base-pair deletion (c.1799_1801delTGA), resulting in a deletion of lysine at codon 601 and a deletion c.1799_1801delTGA that results in a valine-to-glutamate substitution at codon 600 (p.V600_K601>E) while preserving the reading frame. A BRAF K601E mutation was not found. RAS mutations were observed in 18 (33%) tumors (NRAS, 22%; HRAS, 6%; KRAS, 6%). Mutations of the three RAS genes were detected in codon 61 but not in codons 12 and 13. There was a decreasing trend of RAS mutation rates associated with an increasing risk of malignancy in the FNAC diagnostic categories. The triage efficacy of FNAC to make a recommendation for surgery was 73% for encapsulated tumors and 79% for infiltrative tumors. Addition of galectin-3 or the BRAF test to FNAC showed no significant improvement in the triage efficacy. However, RAS mutations significantly improved the triage efficacy of FNAC. There was no significant difference in the triage efficacy of FNAC, galectin-3 expression, and the prevalence of somatic mutations between encapsulated and infiltrative tumors. Thyroid FNAC has a low sensitivity for the detection of FVPTC regardless of histologic subtype. Encapsulated FVPTC and infiltrative FVPTC have similar molecular profiles and rates of galectin-3 expression. RAS mutational analysis is more useful than BRAF testing to improve the triage efficacy of FNAC for FVPTC.

Molecular Alterations in Partially-Encapsulated or Well-Circumscribed Follicular Variant of Papillary Thyroid Carcinoma

Studies have described an encapsulated and an infiltrative form of the follicular variant of papillary thyroid carcinoma (FVPTC). Encapsulated FVPTCs have been reported to have virtually no recurrence risk or metastatic potential and to harbor RAS mutations but not BRAF mutations. In contrast, infiltrative tumors have significant metastatic potential, a risk of recurrence, and a BRAF mutation frequency of approximately 25%. In our experience, a substantial number of FVPTCs are neither fully encapsulated nor infiltrative, but instead are partially encapsulated (PE) or well circumscribed (WC). We have previously reported that PE/WC FVPTCs behave in an indolent fashion similar to encapsulated tumors. The purpose of the current study was to evaluate the molecular alterations in PE/WC FVPTC. We identified 28 PE/WC FVPTCs resected consecutively at our institution. Targeted mutation analysis of 41 genes including members of the RAS and RAF families was performed on DNA extracted from formalin-fixed, paraffin-embedded blocks using single-base extension chemistry and mass spectrometry. Lymph node metastases were absent in all cases with sampled lymph nodes, and no patients developed tumor recurrences (median follow-up time, 72.8 months). Overall, 13 cases (46%) harbored RAS mutations, including seven (25%) with NRAS mutations (p.Gln61Arg) and six (21%) with HRAS mutations (five had p.Gln61Arg and one had a p.Gln61Lys substitution). No PE/WC FVPTCs had BRAF mutations. The results of this study confirm our previous finding that PE/WC FVPTCs pursue an indolent clinical course. Additionally, we found that PE/WC tumors have a similar molecular profile to that of encapsulated FVPTCs with frequent RAS mutations (46%) and no BRAF mutations. These molecular results provide further evidence that PE/WC and encapsulated FVPTCs are biologically similar and should be distinguished from more aggressive infiltrative FVPTCs.

Multiple schwannomas of the upper limb related exclusively to the ulnar nerve in a patient with segmental schwannomatosis

Schwannomas are benign encapsulated tumours arising from the sheaths of peripheral nerves. They present as slowly enlarging solitary lumps, which may cause neurological defects. Multiple lesions are rare, but occur in patients with neurofibromatosis type 2 or schwannomatosis. Positive outcomes have been reported for surgical excision in solitary schwannomas. However, the role of surgery in patients with multiple lesions is less clear. The risk of complications such as iatrogenic nerve injury and the high likelihood of disease recurrence mean that surgical intervention should be limited to the prevention of progressive neurological deficit. We report a case of a 45 year old male who presented with multiple enlarging masses in the upper limb and sensory deficit in the distribution of the ulnar nerve. The tumours were found to be related exclusively to the ulnar nerve during surgical exploration and excision, a rare phenomenon. The masses were diagnosed as schwannomas following histopathological analysis, allowing our patient to be diagnosed with the rare entity segmental schwannomatosis. One year post-operatively motor function was normal, but intermittent numbness still occurred. Two further asymptomatic schwannomas developed subsequently and were managed conservatively.

Schwannoma of the arythenoid

ABSTRACTSchwannoma is a benign encapsulated tumor that originates from the Schwann cells lining nerve fibers outside the central nervous system. We report a rare case of schwannoma that arose from the left arythenoid cartilage The patient underwent excision of the mass through microlaryngeal endoscopic procedure. No recurrence was observed during follow-up.

Mediastinal schwannoma: A case report

Schwannomas are neurogenic tumours arising from Schwann cells of neural sheath. The peak incidence of these tumours is in 30s to 50s of life, with men and women being equally affected. Schwannoma is an encapsulated tumour which distinguishes it from neurofi broma without encapsulation. With both Schwannoma and neurofi broma, surgical excision results in cure. Our patient, twenty year male, presented with mild, dull aching pain over right antero-lateral chest and non-productive cough associated with breathlessness on physical exertion. Computed tomography of the chest was suggestive of neurogenic tumour (differential diagnoses: ganglioneuroma/ganglioneuroblastoma). The mass was excised via open right posterolateral thoracotomy and was sent for histopathological examination after which he was diagnosed as having Mediastinal Schwannoma. Mediastinal schwannomas, although generally benign and asymptomatic, should be excised upon discovery to prevent the development of life-threatening complications. DOI: http://dx.doi.org/10.3126/jkmc.v1i2.8148 Journal of Kathmandu Medical College, Vol. 1, No. 2, Oct.-Dec., 2012: 106-109

Visual Diagnosis: Obese 11-month-old Female With Round Facies

1. Nancy L. Beck, MD* 2. Alba E. Morales, MD† 3. R.F. Buchmann, DO‡ 4. R.J. Birusingh, DO§ 1. *Assistant Professor, Division of Endocrinology, Department of Pediatrics, Texas Tech University Health Sciences Center, Lubbock, TX. 2. †Associate Professor, Division of Diabetes and Endocrine, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR. 3. ‡Assistant Professor, Radiology and Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR. 4. §Assistant Professor, Pediatric Pathology, University of Arkansas for Medical Sciences, Little Rock, AR. An 11-month-old girl presents to the clinic for a mild respiratory illness. Her parents also voice concern about their daughter’s appearance and offer a photograph of her taken at age 9 months (Fig 1). Both parents are slim and healthy. Figure 1. The patient at age 9 months. On examination, the infant is noted to have a round face, generalized fine body hair, acne, and central obesity (Fig 2). She currently weighs 9.6 kg (50th percentile for age), her length is 69 cm (10th percentile), and her head circumference is 43 cm (10th percentile). She was born by uncomplicated vaginal delivery having a birthweight of 3.125 kg (25th percentile) and a length of 48 cm (75th percentile). Review of the girl’s growth curves reveals the absence of linear growth during the previous month (Fig 3). Figure 2. The patient at age 11 months. Figure 3. Growth chart reveals cessation of linear growth. The child’s vital signs are normal for her age. She has mild nasal congestion. Her genitalia appear normal, but her neurologic examination shows delayed gross motor skills. She is able to pull to stand but does not cruise or walk. Based on a suspected diagnosis, the patient undergoes several laboratory examinations. Midnight salivary cortisol levels were 29.2 nmol/L (reference <0.3–4.3) and 33.4 nmol/L on consecutive nights. An overnight dexamethasone (0.3 mg/m2) suppression test revealed an 8 am serum cortisol level of 25.4 μg/dL (701 nmol/L) (reference <3 μg/dL or 83 nmol/L). The plasma cortisol concentration at 4 pm was 29.4 μg/dL (811 nmol/L). The results of renal and thyroid function tests were normal. Serum corticotropin levels obtained on two occasions were …

Extrapancreatic solid pseudopapillary neoplasm: Report of a case of primary retroperitoneal origin and review of the literature

Solid pseudopapillary tumors (SPTs) occurring as primary tumors outside the pancreas are exceedingly rare. The present study reports such a case occurring as a non-functional adrenal tumor in a 22-year-old female. The tumor was completely removed from the retroperitoneum by laparoscopic surgery. A well-defined, encapsulated tumor measuring 6×6×5 cm was histologically characterized by a combination of the solid and pseudopapillary growth patterns of tumor cells with eosinophilic cytoplasm. Ectopic pancreatic tissue was also found histologically within the resected tumor. On immunostaining, the tumor was positive for progesterone receptor, CD56, cytokeratin and CD10. The morphological and immunohistochemical features were compatible with those of SPT. To the best of our knowledge, this is the first case report of extrapancreatic SPT with evidence of a pre-existing ectopic pancreas in the retroperitoneum. A review of the published English literature uncovered 12 cases of extrapancreatic SPTs, and revealed that extrapancreatic SPTs are likely to have a favorable clinical course and a clinical profile similar to their pancreatic counterparts.

Risk Stratification of Follicular Variant of Papillary Thyroid Carcinoma

Recent studies have described an encapsulated and an infiltrative form of follicular variant of papillary thyroid carcinoma (FVPTC). While encapsulated tumors have been reported to have virtually no metastatic potential or recurrence risk if angioinvasion and capsular penetration are absent, infiltrative tumors have been found to have a significant metastatic potential and a risk of recurrence. In our experience, a substantial number of FVPTCs are neither fully encapsulated nor infiltrative, but instead are partially-encapsulated (PE) or well-circumscribed (WC). Thus, the aim of this study was to investigate the metastatic potential and recurrence risk of PE/WC FVPTCs in comparison with that of encapsulated and infiltrative tumors. We studied 77 FVPTCs resected between 2000 and 2002 and characterized the tumors as encapsulated, PE/WC, or infiltrative. Histologic assessment was then correlated with lymph node status and clinical outcome. In our cohort, 27 (35%) tumors were encapsulated, 35 (45%) were PE/WC, and 15 (19%) were infiltrative. Lymph node status was similar between PE/WC and encapsulated tumors, but was significantly different between encapsulated and infiltrative groups (p<0.001), and PE/WC and infiltrative groups (p<0.001). Lymph node metastases were absent in all 15 cases of encapsulated tumors and all 9 cases of PE/WC tumors with sampled lymph nodes, but were present in 7 of 9 (78%) cases of infiltrative tumors with sampled lymph nodes. For patients with available clinical follow-up (66 cases, 86%), the median follow-up time was 111 months. No patients with encapsulated tumors recurred, one (3%) patient with a PE/WC tumor had recurrent/residual disease, and two (15%) patients with infiltrative tumors had recurrent/residual disease. The one patient with a PE/WC tumor who had recurrent/residual disease had a tumor bed recurrence 7 years after initial resection. Significantly, this was the only patient in the PE/WC group that had a positive resection margin. Our results demonstrate that PE/WC FVPTCs have a very low metastatic potential/recurrence risk, indicating that they should be distinguished from more aggressive infiltrative FVPTCs.