Giant Cell Carcinosarcoma of the Parotid Gland With a PLAG 1 Translocation in Association With a Pleomorphic Adenoma With HMGA2 Translocation

Salivary gland carcinosarcoma ex pleomorphic adenoma; a case report with molecular characterization

True malignant mixed tumors, also known as salivary gland carcinosarcoma (SCS), are uncommon yet highly aggressive lesions associated with a poor prognosis. These tumors exhibit a distinctive biphasic structure characterized by both epithelial and mesenchymal components. Recent research has shown that the majority of SCS cases stem from pre-existing pleomorphic adenomas (PAs), suggesting a stepwise developmental pattern. In this report, we present a case of a 73-year-old female with SCS and describe the clinical, radiographic, and pathologic observations. Notably, the SCS was associated with a residual PA. The SCS displayed a CTNNB1::PLAG1 gene rearrangement, providing a molecular basis for its origin from the PA. Further DNA genomic analysis exposed mutations in BAP1, PER1, and LRPB1. Our findings provide support to the theory that SCS emerges from a pre-existing PA while highlighting the multiple genetic changes that could contribute to malignant transformation.

Carcinosarcoma of the parotid gland: a case report and review of the literature

BACKGROUND

Carcinosarcoma of the parotid gland is an extremely rare malignancy comprising of 0.04-0.16% of all salivary gland tumors. This is the first case of an adenoid cystic carcinoma with chondrosarcoma to the best of our knowledge. They consist of distinct carcinomatous and sarcomatous components and may arise de novo or from a preexisting pleomorphic adenoma.

CASE PRESENTATION

Herein we present a case of an 80-year-old white female who presented with progressively increasing left facial swelling over 6 weeks. Magnetic Resonance Imagining revealed a mass (3.4 cm) in the parotid gland with a predominant cystic/necrotic component. The cytology was atypical (Milan3) and a total parotidectomy and selective lymph node dissection was done. The resection showed extensive necrosis with high grade sarcomatous (chondrosarcoma) areas. The epithelial component was adenoid cystic carcinoma with perineural invasion. The patient is currently undergoing radiotherapy of the tumor bed and skull base due to propensity of perineural invasion of the adenoid cystic component. The most common carcinomas in carcinosarcomas of salivary glands are adenocarcinoma and squamous cell carcinoma.

CONCLUSION

Carcinosarcoma is a high-grade aggressive lesion with a poor prognosis and should be treated aggressively. More studies are needed to understand the origin of these tumors.

Carcinosarcoma of the deep lobe of the parotid gland in the parapharyngeal region: A case report

BACKGROUND

Salivary carcinosarcoma is an extremely rare tumor containing both malignant epithelial and mesenchymal constituents. This article reports a rare case of carcinosarcoma with salivary duct carcinoma and osteosarcoma as the tumor components. The clinicopathological characteristics, treatment, and prognosis are discussed in conjunction with the literature.

CASE SUMMARY

A 48-year-old man presented with a complaint of a mass in the right parotid region. Osteosarcoma was first considered for assessment by fine-needle aspiration cytology. Physical examination revealed a mass measuring approximately 4 cm × 3.5 cm × 3 cm. The mass, the whole lobe of the right parotid gland, and the right mandible were completely removed during surgery. Postoperative histopathology confirmed carcinosarcoma of the salivary gland.

CONCLUSION

A definite diagnosis of salivary gland carcinosarcoma can only be obtained after complete surgical resection.

A Case of a Coexisting Carcinosarcoma Ex Pleomorphic Adenoma With Langerhans Cell Histiocytosis in the Parotid Gland

Carcinosarcoma ex pleomorphic adenoma is a rare malignant neoplasm, with most cases reported in the parotid gland. We herein report a case of a 75-year-old male referred to our hospital with a long-standing right parotid lesion that was treated in an outside hospital by a superficial parotidectomy. The patient reported a painful, rapidly enlarging mass following the excision. Histopathological examination showed the proliferation of malignant epithelial and mesenchymal elements with a solid sheet of Langerhans cells admixed with eosinophils. The Langerhans cells were reactive to CD1a and BRAF; hence, a diagnosis of carcinosarcoma ex pleomorphic adenoma with Langerhans cell histiocytosis was given. Complete clinical and radiographic workup showed no other organ involvement. The patient underwent total parotidectomy with adjuvant chemoradiation; however, the tumor progressed and showed lung metastasis. We herein report the first case of a concurrent Langerhans cell histiocytosis with associated carcinosarcoma ex pleomorphic adenoma.

Patterns of Care and Outcomes of Carcinosarcoma of the Major Salivary Glands

OBJECTIVE

Carcinosarcoma of the salivary gland is a rare malignant biphasic tumor. The present study investigates the epidemiology and clinical behavior of carcinosarcoma of the major salivary glands using the National Cancer Database (NCDB).

STUDY DESIGN

Historical cohort study.

SETTING

NCDB.

METHODS

All tumors were selected between 2004 and 2018. Patient demographics, tumor characteristics, treatments, and survival were analyzed. Cox regression analysis was performed in surgically treated patients.

RESULTS

We identified 154 patients in the NCDB with carcinosarcoma of the salivary gland. Median age at diagnosis was 66 years (interquartile range, 55-76). Most patients were male (n = 92, 60%). The majority of tumors were in the parotid (n = 122, 79%), followed by submandibular gland (n = 21, 14%). The majority were high grade (n = 93, 95%), and a significant portion had locally advanced disease (pT3-4; n = 65, 62%). Nodal disease was present in more than one-third (n = 35, 36%). The most common treatment was surgery with adjuvant radiotherapy (n = 75, 49%). With a median follow-up of 36 months, the 3-year overall survival was 57.6% (95% CI, 48.7%-68.0%). In univariable analysis, advanced pT stage, pN+ disease, and positive margins were associated with worse survival. In multivariable analysis, age (hazard ratio, 1.02; 95% CI, 1.01-1.04; P = .03) and pT stage (hazard ratio, 2.51; 95% CI, 1.27-4.95; P = .008) remained significant.

CONCLUSION

Carcinosarcoma is a rare salivary gland tumor that frequently presents at a locally advanced stage. Despite multimodality treatments, the outcomes are poor. In the absence of clinical trial data, these data from the NCDB could guide clinicians in the management of this rare disease.

Salivary carcinosarcoma: insight into multistep pathogenesis indicates uniform origin as sarcomatoid variant of carcinoma ex pleomorphic adenoma with frequent heterologous elements

AIMS

The formal pathogenesis of salivary carcinosarcoma (SCS) remained unclear, both with respect to the hypothetical development from either preexisting pleomorphic adenoma (PA) or de novo and the clonal relationship between highly heterogeneous carcinomatous and sarcomatous components.

METHODS AND RESULTS

We performed clinicopathological and molecular (targeted RNA sequencing) analyses on a large series of 16 cases and combined this with a comprehensive literature search (111 cases). Extensive sampling (average 11.6 blocks), combined with immunohistochemistry and molecular studies (PA-specific translocations including PLAG1 or HMGA2 proven in 6/16 cases), enabled the morphogenetic identification of PA in 15/16 cases (93.8%), by far surpassing a reported rate of 49.6%. Furthermore, we demonstrated a multistep (intraductal/intracapsular/extracapsular) adenoma-carcinoma-sarcoma-progression, based on two alternative histogenetic pathways (intraductal, 56.3%, versus myoepithelial pathway, 37.5%). Thereby, early intracapsular stages are identical to conventional carcinoma ex PA, while later extracapsular stages are dominated by secondary, frequently heterologous sarcomatous transformation with often large tumour size (>60 mm).

CONCLUSION

Our findings strongly indicate that SCS (almost) always develops from PA, with a complex multistep adenoma-carcinoma-sarcoma-sequence, based on two alternative histogenetic pathways. The findings from this novel approach strongly suggest that SCS pathogenetically is a rare (3-6%), unique, and aggressive variant of carcinoma ex PA with secondary sarcomatous overgrowth. In analogy to changes of terminology in other organs, the term "sarcomatoid carcinoma ex PA with/without heterologous elements" might be more appropriate.