Carcinoma ex Pleomorphic Adenoma of the Nasal Cavity

Background  

Carcinoma ex pleomorphic adenoma (CXPA) is a malignant epithelial neoplasm arising in a benign mixed tumor (i.e., pleomorphic adenoma or PA); it accounts for approximately 3–4% of all salivary gland neoplasms. CXPA is exceedingly rare in the nasal cavity, with only three cases previously documented.     

Primary and Secondary/ Metastatic Salivary Duct Carcinoma Presenting within the Sinonasal Tract

Traditionally, sinonasal adenocarcinomas have been subdivided into intestinal (ITAC) and non-intestinal (non-ITAC) categories. The latter encompasses salivary-type adenocarcinomas originating from the seromucinous glands of the sinonasal mucosa and non-salivary adenocarcinomas. The non-salivary adenocarcinoma category is further subdivided into low-and high-grade variants. Among salivary-type sinonasal adenocarcinomas, tumors recapitulating salivary duct carcinoma (SDC) are exceedingly rare, but some might have been lumped into the high-grade non-ITAC category. To date, only three primary SDCs originating in the sinonasal tract have been reported. We herein describe 7 cases of SDC including one previously reported case (4 primary sinonasal, 3 metastatic/ extension from parotid gland SDC). The primary tumors affected 3 males and one female aged 60 – 75. Different sites were involved by the primary tumors while the secondary tumors affected the sphenoidal (2) and the frontal + maxillary (1) sinuses. Three primary tumors were de novo high-grade SDC and one was confined to contours of a pre-existing pleomorphic adenoma. All 3 secondary tumors were SDC ex pleomorphic adenoma of the parotid with a long history of recurrences, ultimately involving the sinonasal tract. Androgen receptor was positive in 7/7 cases. Four of 6 cases were strongly HER2/neu + (either score 3 + or with verified amplification). This small case series adds to the delineation of primary sinonasal SDC highlighting that almost half of invasive SDC presenting within sinonasal tract indeed represents extension or metastasis from a parotid gland primary. There is a tendency towards overrepresentation of HER2/neu-positive cases in both categories (primary and metastatic), but this needs clarification in larger studies.     

Introduction: Human Papillomavirus in Head and Neck Cancer: An Update for 2012 with a Focus on Controversial Topics

Carcinoma ex pleomorphic adenoma (Ca ex PA) is a carcinoma arising from a primary or recurrent benign pleomorphic adenoma. It often poses a diagnostic challenge to clinicians and pathologists. This study intends to review the literature and highlight the current clinical and molecular perspectives about this entity. The most common clinical presentation of CA ex PA is of a firm mass in the parotid gland. The proportion of adenoma and carcinoma components determines the macroscopic features of this neoplasm. The entity is difficult to diagnose pre-operatively. Pathologic assessment is the gold standard for making the diagnosis. Treatment for Ca ex PA often involves an ablative surgical procedure which may be followed by radiotherapy. Overall, patients with Ca ex PA have a poor prognosis. Accurate diagnosis and aggressive surgical management of patients presenting with Ca ex PA can increase their survival rates. Molecular studies have revealed that the development of Ca ex PA follows a multi-step model of carcinogenesis, with the progressive loss of heterozygosity at chromosomal arms 8q, then 12q and finally 17p. There are specific candidate genes in these regions that are associated with particular stages in the progression of Ca ex PA. In addition, many genes which regulate tumour suppression, cell cycle control, growth factors and cell–cell adhesion play a role in the development and progression of Ca ex PA. It is hopeful that these molecular data can give clues for the diagnosis and management of the disease.     

Disseminated Carcinoma Ex Pleomorphic Adenoma in an Adolescent Confirmed by Application of PLAG1 Immunohistochemistry and FISH for <Emphasis Type="Italic">PLAG1</Emphasis> Rearrangement

A 16-year-old previously asymptomatic boy presented with complaints of fatigue, weight loss, and back pain for several months. Imaging studies revealed a large superior mediastinal mass, numerous bilateral pulmonary nodules, and multiple lytic bone lesions. A needle biopsy from a sternal lesion showed a poorly differentiated carcinoma, immunoreactive for cytokeratins and EMA and immunonegative for various organ/tissue-specific markers. His past medical history was significant for excision of a parotid gland tumor 5 years earlier. Histologic review of the salivary gland tumor revealed a pleomorphic adenoma containing a microscopic focus of invasive carcinoma (carcinoma ex pleomorphic adenoma). By immunohistochemistry, both the salivary gland tumor and the disseminated carcinoma expressed PLAG1 with a strong nuclear pattern. Fluorescence in situ hybridization (FISH), using dual-color, break-apart probes for PLAG1, showed rearrangement of the gene in both the salivary gland and the disseminated tumors. FISH demonstrated additional cytogenetic aberrations in the carcinoma, including polysomy for chromosome 8 (in both the primary salivary gland and the metastatic tumors) and PLAG1 amplification (in the metastatic tumor). We conclude that in the proper clinicopathologic setting, application of PLAG1 immunohistochemistry and FISH for PLAG1 gene rearrangement may be valuable in establishing the diagnosis of carcinoma ex pleomorphic adenoma as the source of a cancer of unknown primary site.     

<Emphasis Type="Italic">PLAG1</Emphasis> Alteration in Carcinoma Ex Pleomorphic Adenoma: Immunohistochemical and Fluorescence In Situ Hybridization Studies of 22 Cases

Carcinoma ex pleomorphic adenoma (CA-ex-PA) may arise with nearly any histologic subtype of carcinoma of the salivary gland. In the absence of recognizable residual pleomorphic adenoma (PA) or a prior history of PA, distinction of CA-ex-PA from morphologically similar de novo carcinomas may be difficult. Oncogenic rearrangement of PLAG1 (pleomorphic adenoma gene 1) has been established in PA; however, it has not yet been proven that PLAG1 alteration persists in carcinomas developed from preceding PA. We evaluated 22 histologically diverse CA-ex-PA by immunohistochemistry for PLAG1, and/or by FISH targeting PLAG1. Of these, 17 cases were immunoreactive (1+ to 3+) and 5 were immunonegative/rare positive for PLAG1. For comparison, 39 various salivary gland neoplasms were immunostained for PLAG1, of which all scored negative/rare positive. Twelve of 19 CA-ex-PA analyzed by PLAG1 FISH (63 %) were positive for gene rearrangement, 2 showed only a trisomy/polysomy profile, and 5 had a normal pattern. One FISH-positive tumor showed amplification of PLAG1. One of 3 cases analyzed for HMGA2 FISH was positive for gene rearrangement. In our series, the majority of CA-ex-PA harbored altered PLAG1 or HMGA2 genes detectable by FISH. While PLAG1 immunostain was specific for CA-ex-PA against other carcinomas, its application as a standalone discriminatory test was limited by variable expression. We conclude that most CA-ex-PA, regardless of morphologic subtype, carry altered PLAG1 or HMGA2 genes, and that FISH for PLAG1, along with immunohistochemistry for PLAG1, may help discriminate CA-ex-PA from its de novo carcinoma counterpart.     

Schwannoma-Like Pleomorphic Adenoma: A Case Report with Review of the Literature

Pleomorphic adenoma is a common benign salivary gland tumor, which represents about 66 % of benign neoplasms of the salivary glands. Although it can occur in any salivary gland, it is most frequently found in the parotid. Pleomorphic adenomas are renowned for their cytomorphological and architectural heterogeneity that are characterized by intermixed epithelial and mesenchymal-like components. We report a rare case of pleomorphic adenoma of the parotid gland with prevalent schwannoma-like features mimicking a benign schwannoma. Microscopically the tumor showed a prevalence (about 95 %) of schwannoma-like areas with focal (about 5 %) epithelial component with tubular organization. The tumor showed positive immunoexpression for cytokeratin, S-100 protein, and focal expression of p63, CD10 and smooth muscle actin. To the best of our knowledge only six cases of schwannoma-like pleomorphic adenoma have been reported in the literature. The differential diagnosis between this entity and neurogenic and myogenic tumors is discussed.     

Myoepithelial Carcinoma Ex-Pleomorphic Adenoma: A Rare Pathology Misdiagnosed as Pleomorphic Adenoma; With a Novel TERT Promoter Mutation and High PD-L1 Expression

Myoepithelial carcinoma (MECA) is a rare salivary gland (SG) neoplasm (0.1–0.45% of all SG tumors) that often presents with bland cytomorphology and can be misclassified as cellular pleomorphic adenoma (PA) or myoepithelioma. This is particularly challenging in MECA ex-PA cases, especially if tumor shows minimal to no capsular invasion. We report a rare case of a 76-year-old female; history of left superficial parotidectomy with diagnosis (outside hospital) of cellular PA, who re-presented 9 months post surgery with enlarging left parotid mass, neck lymphadenopathy and facial nerve deficits. FNAB of parotid and neck lymph node revealed cellular aspirates with loosely cohesive clusters of myoepithelial cells with occasional chondromyxoid stroma. Prior resection slides were reviewed, and diagnosis of MECA ex-PA was made. Patient underwent left radical parotidectomy, selective neck dissection, with facial nerve sacrifice (due to extensive encasing by tumor). Histology showed a multinodular tumor with pushing borders, zonal arrangement comprising of a hypocellular, necrotic/myxoid center, and a peripheral rim of myoepithelial cells, confirmed by positive S100, and p63. Tumor extensively infiltrated peri parotid soft tissues with multiple foci of lymphovascular and perineural invasion; and metastatic neck lymph nodes. Next generation sequencing revealed a novel TERT promoter mutation (c.-124C > T), not usually described in SG neoplasms. Further, PD-L1 immunohistochemistry showed positive expression, making patient eligible for anti-PDL-1 immunotherapy. This case highlights importance of recognizing the subtle malignant features of MECA in distinguishing it from benign mimics like PA. In addition, presence of TERT mutation opens a new arena for future research to explore potential treatment targets.     

Recurrent pleomorphic adenoma of the palate in a child.

A rare case of recurrent pleomorphic adenoma of the palate in a 9-year-old boy is presented. Pleomorphic adenoma is relatively rare in children compared with its incidence in adults. However, it is the most common benign epithelial tumour of the salivary glands. The majority of pleomorphic adenomata in children occur in the major salivary glands, mainly the parotid gland. Pleomorphic adenomata of the minor salivary glands are rare in children and mainly occur in the palatal glands. Of the few cases of pleomorphic adenoma of the palate reported in children, only one case showed recurrence of the tumour after primary excision. We present the second case of recurrent pleomorphic adenoma of the palate in a child.     

A case report of a rare nasopharyngeal myoepithelial dominant pleomorphic adenoma

IntroductionPleomorphic adenoma is the most common benign salivary gland neoplasm. The majority of cases occur in the major salivary glands; however, they can also originate from the minor salivary glands. The nasopharynx is an uncommon site, but it has been reported in the literature. The characteristic difference of our report from the literature is the young age of our patient and his previous unremarkable medical or surgical history.The objective of this report is to present a case of salivary gland pleomorphic adenoma, discuss radiological and histopathological findings and treatment options.Case presentationHerein we report a case of a 25-year-old male patient presenting with a long-term history of snoring, mouth breathing, and progressive left nasal obstruction. After examining the patient and confirming the diagnosis, patient successfully underwent tumor resection using a combined transnasal/transoral endoscopic approach with no complications following surgery and significant improvement of the previously reported symptoms.DiscussionPleomorphic adenoma of the minor salivary glands can occur anywhere throughout the distribution sites of these glands such as: along the upper aerodigestive tract, parapharyngeal fat spaces, soft palate, the sinonasal, and nasopharyngeal areas.ConclusionThe occurrence of pleomorphic adenoma in uncommon sites has been reported in the literature, and the nasopharynx is considered to be one of these uncommon sites. The mainstay of treatment for nasopharyngeal pleomorphic adenoma is surgical excision as they can grow to giant sizes if left untreated.     

Salivary Duct Carcinoma: New Developments—Morphological Variants Including Pure In Situ High Grade Lesions; Proposed Molecular Classification

Salivary duct carcinoma (SDC) is an aggressive primary salivary malignancy which microscopically resembles high-grade ductal carcinoma of the breast, with both in situ and invasive patterns. It is typically found in older men, most often in the parotid. It can arise de novo or as the malignant component of carcinoma ex pleomorphic adenoma. SDC is generally a hematoxylin and eosin stain-based diagnosis, with special stains and immunohistochemistry acting mainly in a confirmatory role. Other than epithelial markers, SDC expresses androgen receptors in most cases, with true HER2 positivity seen in about 15 %. Based on these data and analogous to similar schemes in the breast, it is suggested that SDCs can be classified into three main groups: luminal androgen receptor positive, HER2+ and basal phenotype. This may form the basis for prognostic information and new therapeutic possibilities. In addition to the usual type of SDC, a few less common morphological variants have been reported: papillary, micropapillary, mucin-rich, sarcomatoid and oncocytic, as well as pure in situ cases.     

Pleomorphic Multicentric Adenoma in the Submandibular Gland

Neoplasms of salivary glands represent a small group among the diseases involving the head and neck complex. In this group, the pleomorphic adenoma is the most frequent neoplasm, yet involves the submandibular gland in only 12.3% of cases. A patient presenting a swelling in the region of the submandibular gland was submitted to an incisional biopsy, where a fragment of the gland and one juxtaposed node were removed. Histologically they were defined as pleomorphic adenoma. Later, the patient was submitted to submandibulectomy and two other nodes were found close to the gland and removed. All specimens were histologically defined as pleomorphic adenoma. This multicentric finding is of great interest, perhaps explaining the recurrence rate of this neoplasm. The patient is in continuous follow-up and has not presented signs of recurrence.     

Co-expression of Myoepithelial and Melanocytic Features in Carcinoma Ex Pleomorphic Adenoma

The presence of melanin pigment and melanocytic markers expression have been rarely reported in salivary gland tumors. Herein, two cases of carcinoma arising in pleomorphic adenoma of the parotid gland and showing diffuse expression of myoepithelial and melanocytic markers are described. The clinical-pathological clues useful in the differential diagnosis with melanoma are discussed. In addition, a review of the pertinent literature is also proposed, discussing the pathologic mechanisms potentially involved in this phenomenon.Supplementary InformationThe online version of this article (10.1007/s12105-021-01299-4) contains supplementary material, which is available to authorized users.     

Bone marrow metastases from small cell cancer of the head and neck

Background. Primary small cell carcinoma of the head and neck is rare. Although the larynx is the most prevalent site of head and neck small cell carcinoma (SCC), this report will concentrate on SCC of the major salivary glands and paranasal sinuses. In all, 33 cases of paranasal sinus and 43 cases of major salivary gland SCC have been reported in the literature. Methods. We report two patients, one with submandibular gland SCC and the other with maxillary sinus SCC. A literature review of all known paranasal sinus and major salivary gland SCC with inclusion of data from these two new cases is undertaken. Discussion of all past and present cases concentrates on sites of metastasis, treatment, and survival. Results. Paranasal sinus SCCs predominantly arise from the nasal cavity, whereas the parotid gland is the primary site in three fourths of major salivary gland SCCs. One half of major salivary gland and three fourths of paranasal sinus SCCs have only local disease at presentation. Both patients in this report developed bone marrow metastases, a feature heretofore not observed in SCC from these primary sites. The patient with maxillary sinus SCC developed the syndrome of inappropriate antidiuretic hormone (SIADH). Conclusion. The paranasal sinus and major salivary glands are rare primary sites for SCCs. Long-term survival with local therapy in patients with local disease can occur, but in patients with metastatic disease survival mirrors metastatic pulmonary SCC. © 1994 John Wiley & Sons, Inc.     

Salivary Gland Tumor: A Review of 599 Cases in a Brazilian Population

Salivary gland tumors consist of a group of heterogeneous lesions with complex clinicopathological characteristics and distinct biological behaviors. Worldwide series show a contrast in the relative incidence of salivary gland tumors, with some discrepancies in clinicopathological data. The main aim of this study was to describe demographic characteristics of 599 cases in a population from Central Brazil over a 10-year period and compare these with other epidemiological studies. Benign tumors represented 78.3% of the cases. Women were the most affected (61%) and the male:female ratio was 1:1.6. Parotid gland tumors were the most frequent (68.5% of cases) and patient age ranged from 1 to 88 years-old (median of 45 years old). The most frequent tumors were pleomorphic adenomas (68.4%) and benign tumors were significantly more frequent in the parotid (75.9%), while malignant tumors were more frequent in the minor salivary glands (40%) (P < 0.05). In conclusion, women and the parotid gland were the most affected and pleomorphic adenoma was the most frequent lesion, followed by adenoid cystic carcinoma and Warthin’s tumor.     

Benign metastasizing pleomorphic adenoma of the parotid gland: a clinicopathologic puzzle

BACKGROUND: Pleomorphic adenoma constitutes the most common benign parotid gland tumor. Local recurrence after surgical treatment (lateral or total parotidectomy) has been described in 1% to 5% of cases. Malignant degeneration has been reported in 2% to 9% of cases of pleomorphic adenoma of salivary gland origin. Metastasizing pleomorphic adenomas without histologic evidence of malignancy have rarely been reported. Metastatic lesions have been discovered in bone, lymph nodes, the lung, oral cavity, pharynx, skin, liver, retroperitoneum, kidney, calvarium, and central nervous system. To the best of our knowledge, we hereby report the first case of pleomorphic adenoma of the parotid gland metastasizing to the ipsilateral maxilla. METHODS: We simultaneously examined apoptosis-related protein expression and markers of cell-proliferation activity in our case of benign pleomorphic adenoma metastasis and compared outcome with a control group of primary parotid pleomorphic adenomas. RESULTS: Analysis of p53, Bcl-2, MIB1, CD 105, p27, and p21 expression did not reveal significant differences between metastasizing pleomorphic adenoma of the salivary gland and the control group of primary parotid pleomorphic adenomas. CONCLUSIONS: Clinical rather than pathologic evidence seems to justify inclusion of metastasizing salivary pleomorphic adenoma in the group of low-grade malignant salivary tumors.     

Solitary Fibrous Tumor with Entrapment of Minor Salivary Gland Tissue: An Unusual Presentation That Requires Exclusion of Pleomorphic Adenoma

We report two unusual cases of solitary fibrous tumor (SFT) of minor salivary glands that microscopically mimicked pleomorphic adenoma. One of these lesions presented in the retromolar region and the other in the buccal mucosa. The microscopic features of these two tumors and their intimate relationship with regional mucous minor salivary glands posed a diagnostic challenge. Awareness of the morphological diversity of SFT coupled to a judicious use of appropriate immunohistochemical probes should prove valuable to accurately segregate SFT from pleomorphic adenoma.     

Myoepithelioma of the parotid gland in a child: a case report

Myoepitheliomas of the parotid glands are very rare in the pediatric population. Only a few cases of myoepitheliomas of the salivary glands have been reported in children. They have some similar features with pleomorphic adenoma. However, they may be malignant and infiltrate locally. Hence, histopathologic examination should be considered to differentiate these tumors. The treatment of myoepitheliomas is complete removal of the tumor. We report a child with myoepithelioma of the parotid gland and review the related literature.     

Adenoid Cystic Carcinoma ex Pleomorphic Adenoma of the Parotid Gland

There is a considerable variation in the histologic subtype of epithelial malignancies among carcinoma ex pleomorphic adenomas (CXPA) and virtually any known carcinoma entity can develop. To our knowledge, adenoid cystic carcinoma (AdCC) ex PA is quite rare despite the fact that de novo AdCC is the fourth most common salivary gland malignancy. We describe a new case of AdCC ex PA in the parotid gland of a 62 year-old woman. In our patient, there was a short interval of time between parotidectomy and local recurrence and rapid development of distant metastases. Although most of the reported cases are considered low-grade, evidence is presented here that AdCC can take the form of a high-grade malignancy in PA.     

Myoepithelial Carcinoma Ex Pleomorphic Adenoma of the Maxillary Sinus: A Case Report and Review of Literature

Myoepithelial carcinoma ex pleomorphic adenoma is defined as a malignant epithelial neoplasm arising from a primary or recurrent benign pleomorphic adenoma. This type of tumor comprises 3.6% of all salivary gland tumors and 12% of malignant ones. Clinically, it most commonly presents as a firm mass in the parotid gland. The development of this neoplasm in the sinonasal and nasopharyngeal regions is extremely rare and only few cases are reported in the literature. The prognosis of myoepithelial carcinoma is variable. Marked cellular pleomorphism, high mitotic rate, and high proliferative activity correspond to a poor prognosis. In this article, the authors report the histopathological features of a clinical case of a 64-years-old patient with a large median maxillary neoplasm diagnosed as myoepithelial carcinoma/ex-pleomorphic adenoma. The tumor was resected and subjected to secondary reconstruction using a revascularized free fibula flap. The myoepithelial derivation of neoplastic cells was demonstrated by immunohistochemical positivity for S-100 protein (strong and diffuse), cytokeratin 14 (strong and diffuse), and GFAP (focal).     

Giant submandibular gland tumor: mucoepidermoid carcinoma within the pleomorphic adenoma (mixed tumor)

Pleomorphic adenoma (mixed tumor) is the most common type of salivary gland tumors, most often involving the parotid glands. The study presented a case of a giant pleomorphic adenoma of the submandibular gland in a 78-year old woman. Due to the initially slow and progressive growth (during a period of 25 years) without treatment, the tumor attained a size of 25×19×16 cm and a weight of 4 kg. The patient underwent surgery. The histopathological examination showed that the tumor was subject to malignant transformation: within the pleomorphic adenoma one observed mucoepidermoid carcinoma lesions of high-degree malignancy. In spite of the good postoperative esthetic and functional effect the patient was diagnosed with distant metastases to the lungs.