True Mixed Tumor Research Articles

Two Extremely Rare Case of Carcinosarcoma Ex Pleomorphic Adenoma.

Carcinosarcoma ex pleomorphic adenoma (CCPA), also known as true mixed malignant tumor, is an extremely rare high-grade aggressive tumor. The histopathologic examination is the gold standard for diagnosis and radiologic imaging also plays an important role. CCPA should be considered in the differential diagnosis of salivary gland tumors when there are findings suggestive of malignancy such as necrosis and diffusion limitation on imaging.

Ameloblastic fibro-odontoma of mandible

Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor. It is considered under the category of ameloblastic fibroma which is believed to be a true mixed tumor, in which both the epithelial and the ectomesenchymal elements are neoplastic in the latest World Health Organization classification. We present a case of 10-year-old male with a left mandibular mass which was diagnosed as AFO due to its characteristic histology.

Novel insights into the mixed germ cell-sex cord stromal tumor of the testis: detection of chromosomal aneuploidy and further morphological evidence supporting the neoplastic nature of the germ cell component.

The existence of a true mixed germ cell-sex cord stromal tumor (MGSCT) of the testis remains controversial. Based on our experience with rare testicular tumors in this spectrum, we sought to perform a detailed clinicopathologic and molecular study of MGCSCT. Eight cases of testicular MGSCT were morphologically reviewed, screened for chromosomal aberrations (using array comparative genomic hybridization (aCGH) and low pass genomic sequencing), and analyzed by next generation sequencing (The Illumina TruSight Tumor 170). Immunohistochemistry for OCT3/4, Nanog, SALL4, DMRT1, and inhibin was performed on the cohort. Clinical data and follow-up were assessed by medical record review. All patients were karyotypically normal men aged 27-74years (median 41). All tumors had a similar biphasic morphology characterized by various proportions of the sex cord component resembling granulosa cell tumor of adult type and the germ cell component cytomorphologically akin to spermatocytic tumor. Germ cells were haphazardly scattered throughout the tumor or arranged in larger groups, without tubular formation. In 4 cases, atypical mitoses were found within the germ cells. Additionally, in 2 cases there was invasion into the spermatic cord, adjacent hilar soft tissue and into the tumor capsule, which contained both tumor components. Immunohistochemically, focal nuclear expression of DMRT1 was found in the germ cell component in 7/7 analyzable tumors, while SALL4 was positive in 6 cases and negative in one case. All tumors were negative with OCT3/4 and Nanog. The sex cord stromal component had immunoreactivity for inhibin in 7/7 analyzable cases. Four of 8 cases were cytogenetically analyzable: 4/8 by low pass genomic sequencing and 2/8 by aCGH. The results of both methods correlated well, revealing mostly multiple chromosomal losses and gains. One case revealed loss of chromosome 21; 1 case had loss of chromosomes 21 and 22 and partial gain of 22; 1 case had loss of chromosomes 22 and Y, partial loss of X, and gain of chromosomes 20, 5, 8, 9, 12, and 13; and the remaining one gain of chromosomes 20, 3, 6, 8, 2x(9), 11, 2x(12), 13, 14, 18, and 19. Three cases were analyzable by NGS; clinically significant activating mutations of either FGFR3 or HRAS were not detected in any case. Follow-up was available for 4 patients (12, 24, 84, and 288months) and was uneventful in all 4 cases. The identification of extratesticular invasion of both the germ cell and sex cord stromal components, the DMRT1 expression, and the presence of atypical mitoses in germ cells argue for the neoplastic nature of the germ cell component. The molecular genetic study revealing multiple chromosomal losses and gains in a subset of the cases provides the first evidence that molecular abnormalities occur in testicular MGSCT. Multiple chromosomal aneuploidies, namely, recurrent losses of chromosomes 21 and 22 and gains of 8, 9, 12, 13, and 20, indicate that the germ cell component might be related to the morphologically similar spermatocytic tumor, which is characterized by extensive aneuploidies including recurrent gains of chromosomes 9 and 20 and loss of chromosome 7. In summary, our data support that rare examples of true MGSCT of the testis do exist and they represent a distinct tumor entity with admixed adult-type granulosa cell tumor and spermatocytic tumor components.

Ameloblastic Fibroma: A Rare Entity of the Mandible

Abstract Ameloblastic fibroma (AF) is an uncommon benign odontogenic true mixed tumor comprising neoplastic epithelial and mesenchymal tissues. It constitutes only approximately 2% of odontogenic tumors and is defined by the World Health Organization (WHO) as “neoplasm composed of proliferating odontogenic epithelium embedded in cellular ectomesenchymal tissue that resembles the dental papilla and epithelial strands and varying degrees of inductive changes and dental hard tissue formation.” The tumor is most common in the first and second decades of life with a slight male predilection. The most common site is the posterior mandible and 75% of the cases are associated with an unerupted tooth. Radiologically, it may present as a unilocular or multilocular lesion. The treatment of choice could range from aggressive curettage for a small unilocular lesion to wide local excision for a large multilocular lesion. The prognosis is usually good, with a recurrence rate of approximately 20%. Here we present a case of a 13-year-old male with a multilocular expansile cystic lesion associated with nonvital tooth 20 and tooth 21 since 2016. An incisional biopsy was performed and the microscopic examination revealed small masses of cellular fibrous and myxoid connective tissue containing long narrow cords of odontogenic epithelium. The odontogenic islands were basophilic with peripheral nuclear palisading of the basal cell layer, consistent with an ameloblastic fibroma. Complete curettage was performed and the patient is being followed up with no recurrence since 2 months. We reviewed the literature with regard to clinical, histopathological, and radiological findings and reached the conclusion that malignant transformation of ameloblastic fibroma into ameloblastic fibrosarcoma is uncommon but well documented. AF needs to be distinguished from ameloblastoma and ameloblastic fibrosarcoma, since these two tumors can be locally invasive and have greater potential for recurrence than ameloblastic fibroma.

Endocervical Adenocarcinoma With Morphologic Features of Both Usual and Gastric Types

The fourth edition of the World Health Organization classification set up new entities of endocervical adenocarcinoma (ECA), namely the "usual type" and "gastric type." These 2 types are considered to be distinct histogenetically because of their differing immunophenotypes, human papillomavirus (HPV) status, and prognoses. Usual-type ECAs (U-ECAs) are virtually always associated with high-risk human papillomavirus (HR-HPV) infection. Gastric-type ECAs (G-ECAs) are believed not to be associated with HR-HPV infection. Morphologically, U-ECA cells are characterized by mucin-poor and eosinophilic cytoplasm, resembling endometrioid carcinoma (a pseudoendometrioid feature). G-ECA cells are characterized by abundant clear or pale, mucinous cytoplasm and distinct cell borders. However, in routine practice we noticed that some ECAs contain morphologically usual type-like components and gastric type-like components in a single tumor; we have named these "G+U" ECAs. The histogenesis of such tumors has not been investigated. We conducted the present study to clarify the clinicopathologic and immunohistochemical features and HPV status of G+U ECAs, and to determine whether G+U ECAs are genuine G-ECAs mimicking U-ECAs or genuine U-ECAs with gastric type-like morphology. We retrospectively analyzed a series of 70 consecutive cases of ECA diagnosed as mucinous ECA, endocervical type, and we reclassified them on the basis of the latest World Health Organization classification. We identified 48 (69%) pure U-ECAs, 9 pure G-ECAs, and 13 G+U ECAs. Ten of the 13 G+U ECAs (77%) showed no HR-HPV infection by in situ hybridization (HPV-unrelated G+U ECAs) and showed frequent HIK1083 expression and aberrant p53 expression in both usual type-like and gastric type-like components. The other 3 G+U ECAs showed HR-HPV infection (HPV-related G+U EACs) and frequent p16+/p53-/HIK1083- immunophenotype in both usual type-like and gastric type-like components. The U-ECAs were characterized by HR-HPV infection detected by in situ hybridization and frequent p16+/p53-/HIK1083- immunophenotype, similar to that of the HPV-related G+U ECAs. In contrast, the pure G-ECAs were characterized by the absence of HPV infection and frequent HIK1083 expression and aberrant p53 expression, similar to that of HPV-unrelated G+U ECAs. G+U ECAs thus represent a heterogenous group composed of genuine G-ECAs and genuine U-ECAs. Most of the G+U ECAs we examined were genuine HPV-unrelated G-ECAs with usual type-like components showing mucin-poor, eosinophilic cytoplasm (pseudoendometrioid morphology). A small population of G+U ECAs was genuine HPV-related U-ECAs with gastric type-like components showing mucin-rich, voluminous cytoplasm. Thus, both types of ECAs can occasionally display patterns of differentiation suggesting a component of the other type but true mixed tumors do not appear to exist. Ancillary techniques (immunohistochemical analysis of p16, p53, and HPV DNA detection assays) should be used to assure proper classification of tumors with mixed morphologic features.

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A case report.

Mixed adenoneuroendocrine carcinomas (MANECs) are rare biphasic tumour types, which are morphologically recognisable as both gland-forming and neuroendocrine neoplasms. Within the gastrointestinal tract, MANECs occur predominantly in the stomach or colorectum. The present study described a case of a MANEC originating from the ampullary region. The patient presented with widespread metastatic disease. Biopsy samples obtained from the ampullary primary tumour disclosed a complex lesion with adenocarcinoma and neuroendocrine small cell carcinoma components, positive for the intestinal transcription factor caudal type homeobox-2 and for neuroendocrine markers, including chromogranin A, synaptophysin, cluster of differentiation 56/neural cell adhesion molecule. By contrast, biopsy samples obtained from metastatic tissue revealed pure neuroendocrine carcinoma. As exemplified by this true mixed tumour, tumour heterogeneity evolves as the major challenge in oncology today, with potentially severe implications for the choice of chemotherapy. The assessment of metastatic sites may render valuable diagnostic information that is crucial for clinical decision-making and patient management.

Giant Parotid Carcinosarcoma (True Malignant Mixed Tumor) Arising in a Pleomorphic Adenoma: Preservation of the Facial Nerve by Retrograde Dissection and Free Flap Reconstruction

Introduction: True malignant mixed tumors are rare forms of salivary gland neoplasms that are comprised of two malignant histological cell types, which are epithelial and mesenchymal in origin. In this case, a woman who first presented with a pleomorphic adenoma 20 years ago developed a carcinosarcoma of the parotid gland. This case is remarkable in that true mixed malignant tumors account for 0.04 to 0.16% of all salivary gland tumors. Furthermore, the origins of such neoplasms are not well described. An extensive review of the literature revealed that a minority of carcinosarcomas arose from biopsy-proven pleomorphic adenomas, with most cases arising de novo.

Extensive ameloblastic fibroma of the mandible: Report of a case with a special reference to its aspiration cytologic findings

Ameloblastic fibroma (AF) is an extremely rare benign odontogenic tumor with a relative frequency between 1.5% and 4.5%, which usually occurs in the first two decades of life. AF is a true mixed tumor, in which the epithelial and the ectomesenchymal elements are neoplastic. There are two variants of AF: Neoplastic and hamartomatous. Although the histopathology of hamartomatous and neoplastic variants of AF are indistinguishable, clinical, and radiologic features can be of some help to distinguish between them. Asymptomatic small unilocular lesions with no or minimal bone expansion in young individuals are likely to be developing odontomas, and large, expansile lesions with extensive bone destruction are neoplasms. We herein describe a massive AF involving mandible in a 12-year-old female patient, suggestive of the neoplastic variant, with a special reference to its aspiration cytologic findings. Fine-needle aspiration cytologic smears showed two different types of cellular elements: A gland like epithelial component, arranged in well-outlined clusters of basaloid cells with palisading of the columnar cells at the borders of those clusters, and a mesenchymal component that consisted of loosely arranged fusiform cells. These cytologic features appear to be sufficiently characteristic to suggest a diagnosis of AF by fine-needle aspiration. However, the confirmatory diagnosis was made on the basis of histopathology, which proved it to be an AF.

Ameloblastic fibroma in six-year-old male: Hamartoma or a true neoplasm

Ameloblastic fibroma (AF) is an uncommon true mixed odontogenic tumor with a relative frequency between 1.5% and 4.5%. Recently, it has been proposed that two subtypes of AF exist: A neoplasm and a hamartomatous lesion. We report a case of AF in left mandibular posterior region in a 6-year-old male patient. The tumor showed unusual and aggressive features that suggested it was a true neoplasm.

Bilateral Ameloblastic Fibroma in A 6 Year Old Child: A Unique Case

ABSTRACT Ameloblastic fibroma (AF) is an extremely rare true mixed benign tumour that can occur either in mandible or maxilla, but is most frequently found in the posterior region of mandible. It is usually seen in the first two decades of life and is associated with tooth enclosure, hence causing delay in eruption or altering the dental eruption sequence. AF is found during routine radiographic evaluation but is clinically and radiographically similar to Ameloblastic fibro-odontoma and odontoma, which makes an accurate diagnosis mandatory as it may change the course of treatment. There has been lot of debate regarding the treatment for AF. We describe a case of bilateral ameloblastic fibroma in the posterior region of mandible in 6 year old child which was treated by conservative curettage with admirable results.

Treatment of large ameloblastic fibroma: a case report

Ameloblastic fibroma (AF) is an extremely rare true mixed benign tumor that can occur in either the mandible or the maxilla, but is most frequently found in the posterior region of the mandible. It usually occurs in the first two decades of life and is associated with tooth enclosure, causing a delay in eruption or altering the dental eruption sequence. AF is diagnosed on routine radiographic evaluation and is clinically and radiographically similar to ameloblastic fibrodontoma and odontoma, which makes an accurate diagnosis mandatory. There is controversy in the literature as to whether treatment should be conservative or agressive. A conservative treatment strategy, such as enucleation and curettage, is usually sufficient. However, extensive lesions require radical treatment. We describe a case of ameloblastic fibroma with a very unusual clinical manifestation: it demonstrated considerable extension but no associated impacted tooth, was located in the anterior region of the mandible, and became symptomatic in the fifth decade of life. A radical surgical approach was taken, with immediate reconstruction.

Maligner Müller-Mischtumor der Harnblase

True mixed epithelial-mesenchymal tumors of the urinary bladder are exceedingly rare, and only two vesical adenosarcomas have been reported to date. These tumors originated from bladder endometriosis, and malignant transformation of endometriosis has been described, with endometrioid and clear-cell carcinomas being the most common malignancies. We report an unusual case of a malignant mixed Müllerian tumor with heterologous rhabdomyoblastic differentiation, which originated in the urinary bladder of a postmenopausal woman. To the best of our knowledge, such a neoplasm has not yet been reported in the literature.

Carcinosarcoma of the Lacrimal Gland Arising From a Pleomorphic Adenoma

To report a case of the lacrimal gland tumor diagnosed as carcinosarcoma (true mixed tumor) arising from a pleomorphic adenoma. Interventional case report. An 80-year-old Japanese woman was referred with a well-circumscribed tumor in the lacrimal fossa. The tumor was excised, but the deepest portion remained because of heavy bleeding. Histopathologically, the tumor consisted of osteosarcomatous cells. No epithelial or myoepithelial component was identified by immunohistochemistry. Two months later, the tumor progressed further and was excised completely with lateral orbitotomy. The tumor consisted primarily of osteosarcomatous component but also had epithelial components including carcinoma and pleomorphic adenoma. Examinations did not detect local recurrence and metastasis at 10 post-operative months. The tumor was diagnosed as true carcinosarcoma of the lacrimal gland arising from a pleomorphic adenoma. When lacrimal gland tumors containing sarcomatous components are encountered, carcinosarcoma should be included in the differential diagnosis.

Tracheal Carcinosarcoma (True Malignant Mixed Tumour) in a Belgian Blue Heifer

This report describes a case of a carcinosarcoma or true malignant mixed tumour (salivary gland type) of the trachea in a Belgian Blue heifer. At post-mortem examination a nodular, well-circumscribed, firmly attached mass was found in the tracheal wall, severely compressing the tracheal lumen. Histologically the tumour was biphasic, with varying proportions of epithelial elements dispersed throughout a matrix showing varying degrees of myxo-chondroid and cartilaginous differentiation. The histological features of the tumour were consistent with a combination of an adenoid cystic carcinoma and a chondrosarcoma. Immunolabelling demonstrated smooth muscle actin in the cytoplasm of both the epithelial and mesenchymal components, thus fulfilling the diagnostic criteria for a mixed tumour. To our knowledge this is the first report of a mixed tumour of the trachea in a domestic animal.

Ameloblastic fibroma of the maxillary sinus

Ameloblastic fibroma is a rare true mixed tumor of odontogenic origin with both mesenchymal and ectodermal components. It usually arises from the mandibular dentition and presents in the second decade of life. It is a benign slow growing tumor that is less infiltrative than an ameloblastoma but tends to expand bone. It infrequently involves the maxilla and hence the management of these tumors in that region is controversial. The goal of therapy is to avoid cosmetic deformity without compromising on tumor eradication. We present the tenth reported case of this type of tumor in the maxilla, and the second one in an infant.

Ameloblastic fibroma and related lesions: current pathologic concept.

Ameloblastic fibroma (AF) is a true mixed tumor, in which the epithelial and the ectomesenchymal elements are neoplastic. There are two rare variants of AF; granular cell AF and peripheral AF. Ameloblastic fibrosarcoma is a rare tumor, and is regarded as the malignant counterpart of the benign AF. Recent immunohistochemical study using MIB-1 shows labelling indices in the mesenchymal component of the recurrent AF and ameloblastic fibrosarcoma are quite high, in contrast with the conventional AF. Ameloblastic fibrodentinoma is a histologic variant of AF in which dentin or dentinoid tissue has formed, but there is no eveidence that ameloblastic fibrodentinoma exhibit a different biologic behavior than ordinary AF. Ameloblastic fibro-odontoma is a lesion similar to AF, but also showing inductive changes that lead to the formation of both dentin and enamel. Some lesions diagnosed as ameloblastic fibro-odontoma are probably developing odontoma, but the others should not be considered as hamartomatous in nature, since there are rare cases of ameloblastic fibro-odontoma showing true neoplastic behavior, and since the existence of malignant variant is evident. In revised WHO's classification of odontogenic tumors, the terms "ameloblastic fibrodentinoma" and "dentinoma" are used synonymously, however, there are histologic difference between several cases reported previously as "dentinoma" and ameloblastic fibrodentinoma.

Peripheral ameloblastic fibroma of the mandible: Report of a case

Ameloblastic fibroma is an uncommon odontogenic tumor considered to be a true mixed tumor in which the epithelial and mesenchymal elements are both neoplastic.lJ Although the tumor occurs in the jaw, and the posterior mandible is the most common site,2J to our knowledge, a case of peripheral ameloblastic fibroma has not been reported. In this report, we describe a case of peripheral ameloblastic fibroma.

Compound medullary‐papillary carcinoma of the thyroid: true mixed versus collision tumour

HistopathologyVolume 26, Issue 1 p. 104-104 Compound medullary-papillary carcinoma of the thyroid: true mixed versus collision tumour X. MATIAS-GUIU, X. MATIAS-GUIUSearch for more papers by this authorA. CAIXAS, A. CAIXASSearch for more papers by this authorI. COSTA, I. COSTASearch for more papers by this authorR. CABEZAS, R. CABEZASSearch for more papers by this authorJ. PRAT, J. PRATSearch for more papers by this author X. MATIAS-GUIU, X. MATIAS-GUIUSearch for more papers by this authorA. CAIXAS, A. CAIXASSearch for more papers by this authorI. COSTA, I. COSTASearch for more papers by this authorR. CABEZAS, R. CABEZASSearch for more papers by this authorJ. PRAT, J. PRATSearch for more papers by this author First published: January 1995 https://doi.org/10.1111/j.1365-2559.1995.tb00638.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume26, Issue1January 1995Pages 104-104 RelatedInformation

Immunohistochemical characterization of pulmonary blastoma.

The immunohistochemical staining patterns of three pulmonary blastomas (PBs) were studied for markers of mesenchymal (vimentin, muscle-specific actin) and epithelial (cytokeratin, epithelial membrane antigen) differentiation to clarify their phenotypic nature and, possibly, their histogenesis. Epithelial markers were confined to the tubular component of the tumors, and the mesenchymal markers were confined to the stromal component, demonstrating that PBs are true mixed tumors. These findings are consistent with origin from a primitive pluripotential stem cell but do not rule out derivation from a single germ layer with subsequent metaplastic transformation.

Mixed Capillary Hemangioblastoma and Glioma

The histopathologic features of four cases of mixed capillary hemangioblastoma and glioma are described. In three cases, two of which arose in the cerebellum and one in the spinal cord, the hemangioblastic component may have originated from a neoplastic proliferation of the exuberant vascular stroma in a glial tumor. In a fourth case, a cerebellar hemangioblastoma was surrounded by a peripheral rim of atypical neoplastic-looking astrocytes ("reactive glioma"). The controversial concept of the "angioglioma" is reviewed, and it is proposed that the term be used to designate only true mixed tumors of glial and vascular tissue origin whose histologic features conform to the examples described in this report.