Spindle cell variant of ameloblastic carcinoma: a case report and literature review

Clear and Spindle Cell Dedifferentiation in Ameloblastic Carcinoma: A Case Report on a Uncommon Phenomenon

Ameloblastic carcinoma is a rare malignant neoplasm with characteristic histopathological features that are directed towards an aggressive surgical approach than benign odontogenic lesions. It affects people of all ages, mostly in the posterior mandible, without a preference for race or gender. De novo cancer is one of its primary types, while the second type is defined as a malignant change from an antecedent case of benign ameloblastoma. The rapid progression of molecular biology led to the revelation that ameloblastoma contains a BRAF-V600E genetic mutation over 60%. Besides conventional ameloblastic carcinomas, rare histologic variants have also been described in the literature, including clear and spindle cells. These variants pose diagnostic challenges as to whether it is a dedifferentiation or a distinct entity. The dearth of data lends credence to the notion that these histologic variations are related to high-grade neoplasms and more aggressive outcomes. As a result, the current report intends to analyze a series of patients diagnosed with conventional ameloblastic carcinoma of the head and neck region with spindle and clear cell types along with a brief assessment of the literature.

Odontogenic Carcinosarcoma: Clinicopathologic and Molecular Features of Three Cases, a Literature Review and Nomenclature Proposal

BACKGROUND

Odontogenic carcinosarcoma (OCS) is a rare odontogenic malignancy with limited characterization and unexplored molecular features. We report clinicopathologic and molecular findings in 3 additional OCS and review the literature.

METHODS

3 OCS (5.1%) were identified among 59 malignant odontogenic tumors (in our archives from 1992 to 2022). Clinical, radiologic, histopathologic, immunophenotypic, and molecular findings were reviewed. Data from prior case reports and systematic or non-systematic reviews were extracted for analysis.

RESULTS

Three mandibular OCS (age range: 66 to 72 years; 1 male, 2 females) were identified. Case 1 had novel clear-cell morphology, multiple recurrences, and a lethal outcome 28 months after resection. EWSR1 rearrangements were negative, but the tumor showed focal nuclear β-catenin and strong LEF-1 immunoreactivity. Case 2 demonstrated ameloblastic and sclerosing features and encased the inferior alveolar nerve; the patient was disease-free 22 months after resection with adjuvant chemoradiation therapy. LEF-1 was again strongly positive, and next-generation sequencing demonstrated 9p region-(CDKN2A, CDKN2B) copy number loss, and 12q region-(MDM2, CDK4) copy number gain. Case 3 showed clear-cell and markedly sclerosing features; no follow-up information was available. Literature review along with the current cases yielded 20 cases. OCS showed a male predilection (1.5:1), mandibular predominance (80%, typically posterior), and a bimodal age distribution (modes: 27.7 years, 62.7 years). OCS presented as masses (100%), often with pain (55%), and paresthesia (45%). Tumors were typically radiolucent (88.9%), with bone destruction (61.1%), and/or tooth effacement (27.8%). Preoperative biopsy was sensitive for malignancy (85.7%). At least 45% show evidence for a precursor lesion. 3-year DSS and DFS were 58% and 35%, respectively. Regional and distant (usually lung) metastatic rates were 25% and 31.3%, respectively. Increased mitotic rates and presence of tumor necrosis trended toward worse DSS and DFS.

CONCLUSION

OCS is a rare but aggressive malignancy, often arising from precursor tumors and may represent a terminal phenotype rather than a distinct entity. We describe novel clear-cell and sclerosing morphologies. Wnt pathway alterations appear important. Mitotic rates and necrosis may be adverse prognosticators. In keeping with nomenclature trends in other sites, OCS may be more appropriately designated as "biphasic sarcomatoid odontogenic carcinomas."

Ameloblastic carcinoma of the mandible: a case report

BACKGROUND

Ameloblastic carcinoma is a malignant form of ameloblastoma and a very rare odontogenic tumor. We report a case of ameloblastic carcinoma that occurred after removal of a right-sided mandibular dental implant.

CASE PRESENTATION

A 72-year-old female patient visited her family dentist with a complaint of pain around a lower right implant placed 37 years previously. Although the dental implant was removed with the diagnosis of peri-implantitis, the patient experienced dullness of sensation in the lower lip and was followed up by her dentist, but after no improvement. She was referred to a highly specialized institution where she was diagnosed with osteomyelitis and treated the patient with medication; however, there was no improvement. In addition, granulation was observed in the same area leading to a suspicion of malignancy, and the patient was referred to our oral cancer center. The diagnosis of squamous cell carcinoma was made after a biopsy at our hospital. Under general anesthesia, the patient underwent mandibulectomy, right-sided neck dissection, free flap reconstruction with an anterolateral thigh flap, immediate reconstruction with a metal plate, and tracheostomy. Histological analysis of the resected specimen on hematoxylin and eosin staining showed structures reminiscent of enamel pulp and squamous epithelium in the center of the tumor. The tumor cells were highly atypical, with nuclear staining, hypertrophy, irregular nuclear size, and irregular nuclear shape, all of which were suggestive of cancer. Immunohistochemical analysis showed that Ki-67 was expressed in more than 80% of the targeted area, and the final diagnosis was primary ameloblastic carcinoma.

CONCLUSION

After reconstructive flap transplantation, occlusion was re-established using a maxillofacial prosthesis. The patient remained disease-free at the 1-year 3-month follow-up.

Application of a Low-Temperature Plasma Knife to Excise a Spindle Cell Tumor of the Nasal Cavity: A Case Report

To describe a rare case of spindle cell tumor in the nasal cavity of a young female, along with its successful surgical management using a low-temperature plasma knife. A 38-year-old female patient presented with a 6-month history of nasal blockage, hyposmia, and local tenderness. The patient denied a history of definite diagnosis or special treatment. A preoperative magnetic resonance imaging scan revealed the size and extent of the tumor in her nasal cavity. She underwent endoscopic surgery for the sinus using a low-temperature plasma knife. The procedure was performed without complications, and her symptoms resolved within 1 month. The postoperative pathology report suggested a spindle cell tumor in her nasal cavity. Nasal spindle cell tumor is rare and usually presents with no specific clinical symptoms, which should be taken into consideration during diagnosis. In this case, we demonstrate that the effectiveness and safety of sinus surgery can be improved and aided by a low-temperature plasma knife and nasal endoscopy.

Odontogenic carcinosarcoma - A rare case report with review of literature

Odontogenic carcinosarcoma (OCS) is a rare malignant odontogenic tumor (OT) with only a few cases reported in the literature. Its synonyms are ameloblastic carcinosarcoma, malignant mixed OT. It is characterized by a true mixed tumor showing malignant cytology of both epithelial and mesenchymal components. The tumor invaded into adjacent tissues by destroying the bone. A 24-year-old patient visited the outpatient clinic of GITAM Dental College and Hospital, with a chief complaint of growth in the lower right back tooth region for 6 months. Based on clinical and radiographic features, it has been diagnosed as an aggressive central jaw lesion. The patient was further referred for histological examination for confirmatory diagnosis. It has been diagnosed as an adenomatoid OT. The OCS most commonly affects the posterior part of the mandible. A larger number of cases were reported recently, and prolonged follow-up is needed to further clarify the nature of OCS.

Hemangiomatous Ameloblastoma with Spindle Cell Proliferation: A Rare Case Report and Review of Literature

Ameloblastoma is a locally aggressive neoplasm with varied histological patterns. The histomorphologic variants of ameloblastoma bear no prognostic or biologic behavioral significance with possible exceptions of desmoplastic and hemangioameloblastoma. The present paper aims at reporting a case of 38-year-old male with a huge lesion present in the mandibular symphysial region crossing the midline, histopathologically showing hemangiomatous component in follicular and plexiform ameloblastoma along with spindle cell differentiation in the ameloblastic follicles. Spindle cell differentiation in ameloblastoma is rarely reported and the prognostic significance is yet not clear. The present paper also reviews the literature since the diagnosis of this lesion is must as it may lead to surgical complications.

Odontogenic carcinosarcoma with dentinoid: a rare case report

Odontogenic carcinosarcoma is a very rare malignant odontogenic tumor, characterized by malignant epithelial and mesenchymal components. Studies have reported several cases of odontogenic carcinosarcoma, mainly in the upper and lower jaws, with malignant clinical manifestations. Herein, we present the case of a 58-year-old woman with odontogenic carcinosarcoma with dentinoid in the left maxilla. The invasion range was large, and the left maxillary molar was missing. Histology revealed odontogenic carcinosarcoma with bidirectional differentiation characteristics and comprising three components: malignant epithelium, malignant interstitium, and dentinoid. The patient subsequently underwent nasal endoscopic sinus tumor resection, and she recovered well after surgery. After a strict 4-year follow-up, to date, there are still no signs of disease or local recurrence. To our knowledge, this is the first reported case of odontogenic carcinosarcoma with dentinoid. Our study describes the clinical, morphological, and immunohistochemical characteristics of this case, and distinguishes it from related diseases.

Report of a Rare Case of Spindle Cell Ameloblastic Carcinoma and the Diagnostic Utility of Immunohistochemistry

Ameloblastic carcinoma is a rare aggressive malignant epithelial odontogenic tumor. The spindle cell variant of ameloblastic carcinoma (SCAC) is exceedingly rare with 15 cases of SCAC having been reported. Therefore, because of the paucity of cases in literature related to SCAC, the biological behavior of the entity has not been well evaluated. Herein the authors report a case of incidentally diagnosed SCAC in a 20-year-old woman identified on imaging as part of the evaluation of a work-related facial injury. Histologically, the tumor had background of cystic ameloblastoma with areas of dense hypercellular spindle cells with short-to-long intersecting fascicles and occasional herringbone pattern intermixed with solid epithelial nests. Both the epithelial and spindle cells were positive for cytokeratin including cytokeratin 19, D2-40, and transducin-like enhancer of split proteins-1 immunohistochemical stains. The patient was followed for 18 months with no evidence of recurrence or metastasis. To the knowledge this is a first case of reporting D2-40 positivity in spindle ameloblastic carcinoma and this immunostain could be used as helpful marker to diagnose this entity.

Spindle-cell variant of ameloblastic carcinoma: a report of 3 cases and demonstration of epithelial-mesenchymal transition in tumor progression

Ameloblastic carcinoma is a rare odontogenic neoplasm that demonstrates the histologic characteristics of ameloblastoma, accompanied by the cytologic features of malignancy. The spindle-cell variant of ameloblastic carcinoma (SCAC) is exceptionally rare, with a total of 10 cases having been reported in the literature to date. Histologically, a prominent sarcomatoid cell population appears to originate from the epithelial (ameloblastic) component. Like conventional ameloblastic carcinoma, most cases of SCAC occur in individuals older than 40 years of age. Here, 3 additional cases of SCAC are reported, 2 of which occurred in young individuals. Diagnostic criteria to aid in the identification of SCAC are proposed. Finally, histologic and immunohistochemical evidence supporting the occurrence of epithelial-mesenchymal transition in SCAC is presented.

Reconnoitre ameloblastic carcinoma: A prognostic update

AIM

Malignant odontogenic tumor, ameloblastic carcinoma (AC) is challenging to study owing to its rarity, complexity and limited availability of literature. This further makes it difficult to establish its clinical characteristics and prognosis. Our study aimed to evaluate AC's clinico-demographic factors and their relation with prognosis and survival.

MATERIALS AND METHODS

Literature was systematically reviewed for cases pertaining to AC, starting from January 2000 to December 2016. All the required data was obtained, arranged and analysed using Cox regression ratio and Kaplan Meir survival analysis. From the database, 153 cases were retrieved as per the inclusion/exclusion criteria.

RESULTS

The results demonstrated that age of patient, mode of treatment and metastasis affects overall survival. The categorisation of AC as primary or secondary type does not have any role in determining prognosis.

CONCLUSION

Overall survival of AC patient depends upon age, site, treatment and metastasis. For a better prognosis early surgical management of the tumor appears to be the most favourable mode of treatment.

A Rare Case Report of Spindle Cell Ameloblastic Carcinoma Involving the Mandible

Ameloblastic Carcinoma (AC) is uncommon malignant epithelial odontogenic tumour of jaw, with characteristic histologic features and behavior. Clinically, it has aggressive, infiltrative growth pattern with a distinct predilection for mandible. It exhibits histologic features of ameloblastoma and gets dedifferentiated overtime to culminate in carcinoma. Majority of the cases arise denovo (primary) and only few cases arise from a pre-existing ameloblastoma (secondary). Spindle-cell differentiation in ameloblastic carcinoma is rare; Salter described it as a separate entity "low-grade spindle cell ameloblastic carcinoma. Here we report a case of 32-year-old female patient who presented with a swelling present for past six months. It was diagnosed as Spindle cell Ameloblastic Carcinoma (SpAC), after the hemimandibulectomy the patient was under regular follow up for 14 months, no sign of recurrence was seen.