S100, alpha-smooth muscle actin and cytokeratin 19 immunohistochemistry in odontogenic and soft tissue myxomas

Extraskeletal myxoid chondrosarcoma of the gingival: a rare case report and review of the literature

BACKGROUND

Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant tumor described in the head and neck region, especially in the gingival. We present one case arising in the gingival of right mandible, and briefly reviewed the related literature.

CASE PRESENTATION

A 24-year-old male patient with a lesion of 3.5*2.0 cm in buccal gingival of right posterior mandible for 2 months. The tumor was composed of cartilaginous structures and myxoid matrix. Immunohistochemical(IHC) showed that the tumor cells to be positive for vimentin, focally positive for S-100, negative for calponin, SMA, SOX10. The Ki-67 labelling index was 80%. Fluorescent in situ Hybridization (FISH) was positive for NR4A3 rearrangement.

CONCLUSIONS

Due to its unusual site and low incidence in the oral region, a combination of histological findings, immunohistochemistry, and molecular pathology as well as differential diagnosis with other diseases should be taken into consideration in the process of clinical diagnosis and treatment.

Odontogenic Fibromyxoma of Maxilla: a Rare Case with Intriguing Pathology

Fibromyxoma is a rare benign odontogenic tumor of mesenchymal origin which has a potential for a highly aggressive turnout. We present the case of a 30 year old lady who came with a slow-growing swelling in the oral cavity, which turned out to be a fibromyxoma in an unusual location-maxilla. The lesion was excised completely without any bony or soft tissue remnant and the histopathological examination confirmed the diagnosis. The rest of the course was uneventful and the patient is in follow up without any recurrence.

Oral intramuscular myxoma: case report and brief review of the literature

OBJECTIVE

Myxomas are rare benign mesenchymal soft tissue tumors that seldom affect the head and neck area. The present report describes a rare case of intramuscular myxoma of the oral cavity and briefly reviews the literature regarding the occurrence of these lesions in the maxillofacial area.

STUDY DESIGN

A 59-year-old patient was referred for the development of a slow-growing tumefaction in the right buccal mucosa in the previous 12 months. Magnetic resonance imaging was performed to characterize the lesion's dimensions and its relationship with the surrounding structures, and it revealed intramuscular localization in correspondence with the medial pterygoid muscle. Incisional biopsy was carried out to aid in the final diagnosis.

RESULTS

Histology revealed the presence of an intramuscular myxoma, characterized by discontinuous margins and locally infiltrating muscular fibers. A second surgery was performed to totally remove the lesion. Follow-up at 6 months did not show any signs of recurrence. A literature search was performed to retrieve data on the incidence of oral intramuscular myxomas.

CONCLUSIONS

To the best of our knowledge, this is the first case of intramuscular myxoma of the medial pterygoid muscle reported in the literature. Although rarely encountered, intramuscular myxomas should be considered when performing differential diagnoses of soft tissue masses at the level of the masticatory muscles.

Sinonasal Myxoma: A Distinct Lesion of Infants

An 11 month old Caucasian male presented with swelling of the right side of the nose and buccal vestibule of unknown duration. Radiographic images revealed a well-circumscribed, hypodense soft tissue mass with a peripheral hyperdense circumference involving the anterior aspect of the right maxilla. The lesion extended from the inferior aspect of the orbital rim superiorly to the maxillary bone inferiorly without invading any nearby structures. The lesion was completely resected via combined extraoral and intraoral approach. The clinical, radiographic, histologic and immunohistochemical features of a sinonasal myxoma in an infant are discussed.

Diagnosis and Management of Odontogenic Myxoma in a Dog

A three-year-old Jack Russell terrier dog was presented with a large gingival mass of the right mandible extending from the fourth premolar to the first molar teeth. Radiographic examination of the expansile mass revealed moth-eaten, honeycomb-like lyses of the mandible and extended into the mandibular alveolar canal based on computed tomography. The histopathological diagnosis of the biopsy was odontogenic fibromyxoma. Mandibulectomy with resection of the associated soft tissues was performed. Surgical management was curative with no clinical signs of disease 2-years after treatment. These neoplasms are slow growing, locally destructive tumors of odontogenic origin that have been described in the jaw of only one dog. In this paper, the clinico-radiological and pathologic features, diagnostic modalities as well as the factors that might influence treatment outcome of odontogenic myxomas are discussed. These odontogenic tumors are currently excluded from the WHO classification of odontogenic tumors in domestic animals and inclusion in future classifications systems is proposed.

Odontogenic myxoma: Report of three cases and retrospective review of literature in Indian population

Purpose:

To review the clinical pattern and treatment modalities meted out to patients of odontogenic myxoma (OM) in Indian population in last 30 years and also to report 3 cases of OM.

Method:

A retrospective review of radiograph and histopathology of three cases of odontogenic myxoma treated between 2005 and 2011 was done. Immunohistochemical analysis was performed to examine the pattern of vimentin and NSE. Also a computerized literature search using Medline and Google scholar was conducted for published articles on OM in Indian population in last 30 years.

Result:

A total of 32 OM cases reviewed from 25 articles retrieved. Out of them 24 myxomas were present in maxilla, only 8 were in mandible and a single case was present in supraglottic region (larynx). Surgical procedure carried out was excision and curettage in 16 patients and resection with safe margin followed by reconstruction 13 patients. All the three reported cases were successfully treated by tumor enucleation and peripheral ostectomy with no recurrence after 3 to 7 years.

Conclusion:

Odontogenic myxoma is a rare odontogenic tumor with inconclusive clinical and radiographic features, hence histopathological examination is mandatory to confirm its diagnosis. Although the immunohistochemical analysis may help in diagnosis but plays no role in guiding treatment planning or predicting the rate of recurrence. Currently we lack data on number of reported OM cases in Indian population as author feels more patients must have been treated then reported.

The diagnostic usefulness of immunohistochemistry for odontogenic lesions

The diagnosis of odontogenic tumors can be challenging, largely due to their rarity and consequent difficulties in gaining experience in their assessment. In most cases, careful attention to morphology, in conjunction with clinical and radiological features will allow a diagnosis to be made. However, in some cases, immunohistochemical analysis of the tumor may be useful. In this review we will outline the immunohistochemical expression profile of normal developing odontogenic tissues and a range of odontogenic tumors. In many cases the immunohistochemical markers are neither specific nor sensitive enough to be of help in diagnosis, but in some cases such analysis may prove very useful. Thus we have outlined a limited number of circumstances where immunohistochemistry may be of use to the practicing diagnostic pathologist.

Oncologic profile of maxillary odontogenic myxoma: A rare case

Odontogenic myxoma (OM) is an ectomesenchyme derived neoplasm, almost exclusively found in jaws. This article presents a maxillary OM with a brief review of the molecular and proteomic antecedents of OMs, capturing its histopathogenesis.

Locally infiltrative ameloblastic fibroma in a rhesus macaque (Macaca mulatta) with characterizations of its proliferating activity and biological behavior

An 8-year-old male rhesus macaque (Macaca mulatta) presented with unilateral enlargement of the left mandible. Radiographs revealed a marked expansion of the left mandible with a multilocular radiolucent mass with abundant osteolysis. The mass was grossly firm, fleshy, and gelatinous on the cut surface. Histologically, the mass was locally infiltrative and composed of neoplastic epithelial and mesenchymal components that stained positive for cytokeratin and vimentin, respectively. Occasional densely spherical condensations of fibroblasts resembling the cap stage of odontogenesis were present in the mesenchyma. Immunohistochemical staining with Ki-67, S-100, and CD34 indicated that both epithelial and mesenchymal components of the neoplasm had low proliferation. Alcian blue, periodic acid-Schiff, and trichrome stains showed an immature stromal component with no collagen formation. Based on the clinical, histologic, and immunophenotypic features, the tumor was identified as a locally infiltrative ameloblastic fibroma.

The orosomucoid 1 protein (α1 acid glycoprotein) is overexpressed in odontogenic myxoma

BACKGROUND

Odontogenic myxoma (OM) is a benign, but locally invasive, neoplasm occurring in the jaws. However, the molecules implicated in its development are unknown. OM as well as Dental Follicle (DF), an odontogenic tissue surrounding the enamel organ, is derived from ectomesenchymal/mesencyhmal elements. To identify some protein that could participate in the development of this neoplasm, total proteins from OM were separated by two-dimensional electrophoresis and the profiles were compared with those obtained from DF, used as a control.

RESULTS

We identified eight proteins with differential expression; two of them were downregulated and six upregulated in OM. A spot consistently overexpressed in odontogenic myxoma, with a molecular weight of 44-kDa and a pI of 3.5 was identified as the orosomucoid 1 protein. Western blot experiments confirmed the overexpression of this protein in odontogenic myxoma and immunohistochemical assays showed that this protein was mainly located in the cytoplasm of stellate and spindle-shaped cells of this neoplasm.

CONCLUSION

Orosomucoid 1, which belongs to a group of acute-phase proteins, may play a role in the modulation of the immune system and possibly it influences the development of OM.

Odontogenic myxoma of the mandible

Odontogenic myxomas are benign but locally aggressive neoplasms found almost exclusively in the jaws and arise only occasionally in other bones. We present a rare case of odontogenic myxoma occurring in the mandible of a 19-year-old male patient with a brief review of clinical and radiological features, and diagnostic and operative dilemmas in managing the same.

Collagenous myofibroblastic tumor of the mandible: case report of a unique locally aggressive neoplasm

We report a locally aggressive collagenous myofibroblastic neoplasm of the mandible in an 18-year-old male. Clinically, the lesion presented with rapid growth and irregular mandibular bone destruction. Grossly, the tumor was 10 cm in greatest dimension, light-tan, firm, and involving the posterior one-thirds of the body and inferior half of the left mandibular ramus. Histologically, the lesion was composed of a loose spindle cell proliferation interspersed with periodic dense bands of collagen. The spindle cells reacted positively to smooth muscle actin, calponin, and focally to desmin and were negative for S-100, pan-cytokeratin, CD99, CD34 and caldesmon, supporting myofibroblastic derivation. At our 4 year follow-up, the patient remained free of local recurrence and surgery related complications. The clinicopathologic findings and the differential diagnosis of this lesion is presented and discussed.

GNAS1 mutations occur more commonly than previously thought in intramuscular myxoma

Mutation detection plays an important role in diagnostic pathology, not only in providing a tissue diagnosis, but also in predicting response to antitumourigenic agents. However, mutation detection strategies are often hampered by masking of mutant alleles by wild-type sequences. Coamplification at lower denaturation temperature PCR (COLD-PCR) reportedly increases the proportion of rare variant sequences in a wild-type background by using PCR cycles in which the denaturation temperature is reduced to favour product formation with lower melt temperatures and heteroduplexes arising from minor variants. Intramuscular myxoma is a rare benign soft tissue neoplasm that occurs sporadically and less commonly in association with fibrous dysplasia (Mazabraud's syndrome). Fibrous dysplasia results from activating GNAS1 mutations, and the same mutations have been identified in small numbers of intramuscular myxoma. The aim of the study was primarily to establish whether COLD-PCR is more sensitive than conventional PCR; this was achieved by testing for GNAS1 mutations in intramuscular myxomas using the two methodologies. Mutations were detected in 8 of 28 (29%) cases of intramuscular myxomas using conventional PCR followed by mutation-specific restriction enzyme digestion (PCR-MSRED) whereas 17 of 28 (61%) mutations were detected using COLD-PCR/MSRED. Mutations were detected in two cases where a diagnosis of low-grade myxofibrosarcoma had been favoured over intramuscular myxoma. No mutations were detected in an additional 9 low-grade and 19 high-grade myxofibrosarcomas, and another 40 control samples. This study shows the power of COLD-PCR compared with conventional PCR in mutation detection, and shows that GNAS1 mutation detection increases diagnostic accuracy when distinguishing between intramuscular myxoma and low-grade myxofibrosarcoma.

Intramuscular myxoma of the masseter muscle. A case report

PURPOSE

Myxomas are benign, locally infiltrative, connective tissue tumors that rarely occur in the head and neck region. The purpose of this paper is to describe a very rare case of an intramuscular myxoma of the masseter muscle.

METHODS

A 74-year-old man presented with a 2-year history of a painless swelling over his left preauricular region. Computed tomography scan showed an intramasseter well-defined soft tissue mass. After a preauricular approach, a circumscribed solid gelatinous tumor was excised with thin margins including adjacent muscle tissue.

RESULTS

Histopathology revealed an intramuscular myxoma, completely resected. The patient made an uneventful recovery, and there were no signs of recurrence 26 months after surgery.

CONCLUSIONS

Intramuscular myxoma of the masseter is an extremely rare entity, but it must be considered in the differential diagnosis of the swellings of the preauricular region.

Pulmonary myxoma in a sheep

Pulmonary myxoma is an uncommon neoplasm. A pale tan, lobulated, and well-circumscribed mass was discovered at slaughter in the left lung of a 5-year-old sheep. Histologically, the tumor was composed of spindloid to stellate cells in a myxoid matrix. Neoplastic cells were immunohistochemically positive for vimentin but did not express cytokeratins, S-100 protein, smooth muscle actin, desmin, or p53. On the basis of the histologic and immunohistochemical findings, this tumor was diagnosed as a myxoma.

Odontogenic myxoma: clinico-pathological, immunohistochemical and ultrastructural findings of a multicentric series

The aim of this study was to analyze the clinico-pathological and immunohistochemical features of 62 cases of odontogenic myxoma (OM) diagnosed in three Oral Pathology Diagnostic Services in Latin America, as well as to describe the ultrastructural features of three of these cases. OM showed a wide age range (9-71 years), with a mean of 27.97 yr (SD: 11.01) and a male to female ratio of 1:2.2. Mandible was affected in 37 cases (59.6%) and maxilla in 25 (40.4%), with 61.3% located in the posterior region. Thirty-nine cases (62.9%) were multilocular and 23 (37.1%) unilocular. Size ranged from 1 to 13 cm, (mean: 5.2 cm). Thirty-seven multilocular (54.8%) and 6 unilocular lesions (26%) were larger than 4 cm (p<0.05). Epithelial islands were identified in 5 cases (8%) on H&E stained sections, but AE1/AE3 and CK14 disclosed these structures in 15 cases each (24.2%); CK5 was positive in 8 (12.9%); CK7 in 2 (3.2%) and CK19 in only 3 cases (4.8%). All cases were negative for CKs 8 and 18, S-100 protein, NSE and CD68, and showed a low index of expression of Bcl2 and ki-67 proteins (<1%). Mast cell antibodies showed these cells in 45 cases (72.6%). Myofibroblastic differentiation evidenced by myofilaments and fibronexi was found in one case out of the three studied by TEM and 29 cases (46.7%) were positive by immunohistochemistry for alpha actin. In conclusion, only a minority of OM had epithelial islands, and only 3 cases expressed CK 19, indicating an odontogenic epithelium origin. Immunohistochemical and ultrastructural findings suggest that OM is a mesenchymal neoplasm in which several factors may contribute to its pathogenesis, including myofibroblastic differentiation and the participation of mast cell products. However, further investigations are needed to better understand the participation of these elements in this particular neoplasm.

MIB-1, Bcl-2 and p53 in odontogenic myxomas of the jaws

Odontogenic myxoma is a rare benign neoplasm occurring in the jaws. Microscopically, it is composed of spindle or stellate-shaped cells arranged in a mucinous matrix. In some cases (20%), odontogenic epithelial islands may be found. The Authors evaluated p53, MIB-1, and Bcl-2 expressed by the epithelial and stromal elements in 12 cases of odontogenic myxoma of the jaws. The cells of the odontogenic epithelium were positive for Bcl-2, p53 and MIB-1. The stromal cell showed a high positivity for MIB-1. Proliferation of both the epithelial and stromal components could be related to the growth of this odontogenic tumour.

Childhood maxillary myxoma: case report and review of management

Myxomas are benign neoplasms of uncertain origin and etiology. First described by Virchow in 1863, they are derived from primitive mesenchymal structures and feature components of the umbilical cord. More recently, in 1995, Takahashi et al., through extensive research confirmed the fibroblastic and histiocytic origin of the tumor. We present a case in a female infant whose outcome and follow-up are discussed as well as a literature review in order to discuss many features of this rare pathology.

Soft tissue myxoma: report of an unusual case located on the gingiva

BACKGROUND

Soft tissue myxoma of the oral cavity is rare. Only three cases of myxoma of gingiva have been reported in the literature. We present a case of soft tissue myxoma arising from the left maxillary adherent gingiva in a 42-year-old male [correction of female] patient.

METHODS

Histological examination showed spindle-shaped cells in a myxoid stroma. Immunohistochemical stains with S-100 protein were negative, while those with vimentin were positive.

RESULTS

Clinical examination revealed a soft tissue mass, with tense elastic consistency on palpation. The overlying mucosa was normal and healthy. A clinical diagnosis of fibroma was given. Histological examination showed spindle-shaped and stellate cells, arranged in a myxoid fibrous stroma, with collagen fibres distributed uniformly. Scattered islands or strands of inactive odontogenic epithelium were present. On the basis of the histological and immunohistochemical findings, the final diagnosis was soft tissue myxoma.

CONCLUSIONS

Further studies are necessary to clarify the origin and histogenesis of this lesion.

Myxomatous lesions of the maxilla in children: a case series and review of management

OBJECTIVE

A paucity of data exists in the literature regarding the pediatric bony myxoma. Controversy exists regarding both its histopathologic origins and surgical management. The purpose of this study was to report on our experience in managing these patients, including diagnostic work-up, histopathologic findings and an evaluation of surgical treatment outcomes.

METHODS

A retrospective review was undertaken of all consecutive cases of pediatric bony myxoma treated between 1988 and 2001. Tumors were analyzed in terms of clinical data, imaging studies, histopathology and surgical treatment. A selective review of the literature regarding management of the bony myxoma is also presented.

RESULTS

Five lesions were identified, all of which occurred in the maxillary bone. Histopathologically our cases did not show a strong association with odontogenic epithelium. All cases were treated by surgical resection with conservative margins. No recurrences were documented over a mean follow-up period of 8.5 years.

CONCLUSION

The bony myxoma is a rare lesion in the pediatric population, and initial clinical or radiological misdiagnoses are not uncommon. The presupposed odontogenic origin of these tumors may need reassessment. Conservative resection with narrow margins is a safe and effective therapy for myxomas of the pediatric maxilla.

Maxillary odontogenic myxoma: a diagnostic pitfall on aspiration cytology

A painless, slow-growing cheek swelling in a young male clinically considered a salivary gland mass was aspirated. Cytology smears were hypocellular. The striking feature was abundant myxoid material with a few monomorphic oval cells, interpreted as myxoid variant of pleomorphic adenoma. Subsequent CT scan was suggestive of a malignant tumor but biopsy confirmed it as myxoma. Myxoma of the jaw is a rare benign tumor that has a tendency for bone destruction, invasion into surrounding structures, and a relatively high recurrence rate. Maxillary myxoma is less frequent but behaves more aggressively than in the mandible, as it spreads through the maxillary sinus. Cytologically, it should be differentiated from other tumors showing predominant myxoid change. Awareness of potential diagnostic pitfalls and careful evaluation of clinical and radiological data is necessary to narrow the differential diagnosis.

Keratin expression in human tissues and neoplasms

Keratin expression in human tissues and neoplasms Keratin filaments constitute type I and type II intermediate filaments (IFs), with at least 20 subtypes named keratin 1-20. Since certain keratin subtypes are only expressed in some normal human tissues but not others, and vice versa, various tissues have been subclassified according to the pattern of keratin staining. Simple epithelia generally express the simple epithelial keratins 7, 18, 19, and 20, while complex epithelia express complex epithelial keratins 5/6, 10, 14, and 15. When an epithelium undergoes malignant transformation, its keratin profile usually remains constant. The constitution and expression patterns of keratin filaments in human epithelial neoplasms are complex and often distinctive. In this article, we first briefly review the molecular and cell biology of keratin filaments. We then focus on the expression patterns of keratin filaments in various human neoplasms.

Odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws

Odontogenic cysts that can be problematic because of recurrence and/or aggressive growth include odontogenic keratocyst (OKC), calcifying odontogenic cyst, and the recently described glandular odontogenic cyst. The OKC has significant growth capacity and recurrence potential and is occasionally indicative of the nevoid basal cell carcinoma syndrome. There is also an orthokeratinized variant, the orthokeratinized odontogenic cyst, which is less aggressive and is not syndrome associated. Ghost cell keratinization, which typifies the calcifying odontogenic cyst, can be seen in solid lesions that have now been designated odontogenic ghost cell tumor. The glandular odontogenic cyst contains mucous cells and ductlike structures that may mimic central mucoepidermoid carcinoma. Several odontogenic tumors may provide diagnostic challenges, particularly the cystic ameloblastoma. Identification of this frequently underdiagnosed cystic tumor often comes after one or more recurrences and a destructive course. Other difficult lesions include malignant ameloblastomas, calcifying epithelial odontogenic tumor, squamous odontogenic tumor, and clear-cell odontogenic tumor. Histologic identification of myxofibrous lesions of the jaws (odontogenic myxoma, odontogenic fibroma, desmoplastic fibroma) is necessary to avoid the diagnostic pitfall of overdiagnosis of similar-appearing follicular sacs and dental pulps. Fibroosseous lesions of the jaws show considerable microscopic overlap and include fibrous dysplasia, ossifying fibroma, periapical cementoosseous dysplasia, and low-grade chronic osteomyelitis. The term fibrous dysplasia is probably overused in general practice and should be reserved for the rare lesion that presents as a large, expansile, diffuse opacity of children and young adults. The need to use clinicopathologic correlation in assessing these lesions is of particular importance. Central giant cell granuloma is a relatively common jaw lesion of young adults that has an unpredictable behavior. Microscopic diagnosis is relatively straightforward; however, this lesion continues to be somewhat controversial because of its disputed classification (reactive versus neoplastic) and because of its management (surgical versus. medical). Its relationship to giant cell tumor of long bone remains undetermined.

Intramuscular myxoma causing lumbar radiculopathy. Case report and review of the literature

The authors present the rare case of a myxoma, a benign soft-tissue tumor of mesenchymal origin noted for occurring in the left atrium of the heart, which was found in the lumbar paraspinal muscles of an 80-year-old woman. This patient experienced low-back pain for over 20 years and had noted its increasing severity with the development of an L-5 radiculopathy over a 3-month period. Magnetic resonance imaging of the lumbar spine revealed a large paraspinal mass that invaded the L-5 vertebral body and the left foramen of L5-S1. A computerized tomography-guided biopsy sampling procedure was performed, and examination of the specimen revealed an intramuscular myxoma. The patient underwent resection of the tumor and nerve root decompression. The diagnosis of intramuscular myxoma was confirmed, and the patient experienced complete resolution of her presenting symptoms. This patient represents the third reported case (the first in the English-language literature) of an intramuscular (paraspinal) myxoma presenting with lumbar nerve root compression.

A joint myxoma in a dog

Myxomas of the joints are extremely rare in domestic animals, only four cases, all in dogs, having been reported previously. This paper describes a myxoma originating from the synovium of the right radiocarpal joint of a mature female Dobermann pinscher with right front limb lameness. The tumour was excised surgically and no recurrence was detected during a 2-year follow-up period. Immunohistochemically, the tumour cells reacted with antibodies to vimentin and S100 protein but not with antibodies to cytokeratins (high and low molecular weight) or human callus keratin.

Odontogenic myxofibroma arising from the periodontal ligament in the maxillary molar region

A rare case of odontogenic myxofibroma, which arose from the periodontal ligament and expanded into the oral cavity resulting in an epulis-like lesion in a 52-year-old man, is reported including details of studies using lectin histochemistry, transmission electron microscopy (TEM), and immunohistochemistry. Most of the tumor cells, which appeared spindle-like with abundant rough endoplasmic reticulum and some microfilaments by TEM, showed immunoreactivity for mesenchymal markers. Some tumor cells, which were polygonal and contained many microfilaments and some filament bundles, were immunoreactive for muscle markers. The present case was considered to consist of many fibroblasts and some myofibroblasts.