Sinonasal tract adenoid cystic carcinoma ex-pleomorphic adenoma: a clinicopathologic and immunophenotypic study of 9 cases combined with a comprehensive review of the literature

Sinonasal Adenocarcinomas: An Update

Among sinonasal malignancies, adenocarcinomas account for the second most common entity after squamous cell carcinoma. They span a wide spectrum of neoplasms with heterogeneous features including intestinal-type adenocarcinoma (ITAC), non-intestinal-type adenocarcinomas (non-ITACs), and salivary-type adenocarcinomas. ITAC basically mirrors the histopathological aspects of gastrointestinal counterparts, showing variable tubulo-papillary, colonic, and mixed patterns with mucin production in 20% to 25% of cases. By contrast, non-ITACs do not show any differentiation toward intestinal or salivary phenotype, and they mainly represent a diagnosis of exclusion lacking a proper histopathological and molecular definition.

Clinical and Morphological Aspects of Aggressive Salivary Gland Mixed Tumors: A Narrative Review

Salivary gland tumors are a rare and heterogeneous group of neoplasms of the head and neck region. The mixed category of these tumors include the following entities: pleomorphic adenoma (PA), carcinoma ex pleomorphic adenoma (CEPA), salivary carcinosarcoma (CS), and metastasizing PA (MPA). The most common benign tumor of the salivary glands is PA. Metastasis and malignant degeneration have been reported in cases of PA of a salivary gland origin. Judging by their behavior, MPA, CEPA, and CS can be considered aggressive tumors. Invasive CEPA has been identified in the parotid gland more frequently. MPA and CS cases reported in the current literature are rare. In this paper, we present, narratively, the clinico-morphological features of this group of mixed tumors.

Influence of p16 Protein Immunostaining on Histopathological Features of Pleomorphic Adenoma and Carcinoma ex- Pleomorphic Adenoma

The objective of this study was to evaluate the role of p16 in histologic characteristics and transition of Pleomorphic Adenoma (PA) to Carcinoma ex-PA (CxPA). So, 60 PA and 4 CxPA were histologic reviewed based on microscopic characteristics proposed by Hellquist, Triantafyllou and Dulguerov (PA) and Morais, Antony and Toluie (CxPA). Immunostaining for p16 was associated in different parenchyma and stroma of both tumors and Fisher's/chi-square tests and Mann-Whitney test were performed (SPSS v20.0, p<0.05). In PA the periductal cells were predominantly p16- and that ductal and myoepithelial cells showed a significant increase in p16+ cells (p<0.001). In CxPA, none of the cases showed p16+ in periductal cells, most parotid cases showed p16+ in ductal cells, and one case of parotid and the submandibular case showed mild immunostaining for myoepithelial cells. There was a small reduction in p16+ in CxPA compared to PA (p=0.537), but in both tumors there was less p16+ cells in solid stroma than other (p<0.001). The p16+ cases of PA had a higher capsular thickness (p=0.047). So, the loss of p16 immunostaining does not seem to be associated with the transition from PA to CxPA, but in both tumors the loss of p16+ cells are related to microscopic aggressiveness.

A Rare Case of Sinonasal Pleomorphic Adenoma

Pleomorphic adenoma (PA) is the most prevalent benign tumor of the salivary glands, characterized by both epithelial and mesenchymal differentiation. It primarily originates within the parotid and submandibular glands, with only rare occurrences in the minor salivary glands. PA in the sinonasal area is extremely rare. Herein, we present a case of a 61-year-old female with a large soft tissue mass in the paranasal sinus and nasal cavity, as evidenced by computed tomography imaging. The patient suffered from repeated nasal congestion for more than 6 months. Eventually, the mass was completely resected using an endoscopic endonasal prelacrimal approach under general anesthesia. Postoperative pathological examination revealed the presence of PA in the nasal sinus.

Carcinoma Ex Pleomorphic Adenomas: An Institutional Experience and Literature Review

OBJECTIVES

To provide an institutional experience with cases diagnosed as carcinoma ex pleomorphic adenoma (CXPA), including the cytologic and histologic findings and clinical follow-up, followed by a comparison to the experience documented in the literature.

METHODS

We identified cases of CXPA diagnosed at our institution from 2011 to 2021 and reviewed the cytologic and histologic diagnoses, as well as the treatment and clinical outcomes. Additionally, a literature review of the English literature was performed on CXPAs from 2011 to 2021.

RESULTS

Forty-one cases of CXPA were identified, with the majority subclassified as adenocarcinoma, not otherwise specified. Five tumors underwent cytogenetic studies and five underwent molecular studies. To date, 36 patients are alive, 8 of whom experienced locoregional recurrence or distant metastasis.

CONCLUSIONS

Our institutional experience was comparable to that reported in the literature. Further studies are required to inquire about the role of molecular profiles of CXPAs in clinical risk assessment.

Glial Fibrillary Acidic Protein Expression Helps Distinguish Pleomorphic Adenoma from Histologic Mimics

Pleomorphic adenoma (PA) is the most common biphasic type of salivary gland tumour to arise in adults. It is a biphasic tumour composed of both luminal (ductal) cells and abluminal (basal and myoepithelial) cells. Other biphasic salivary gland type tumours, both benign and malignant, can mimic PA, especially on small biopsies. Previous studies have shown that glial fibrillary acidic protein (GFAP) is preferentially expressed in PA and can be useful in the distinction from other salivary gland tumours. However, most of these studies were performed on a small subset of tumour types at a time when the classification of salivary gland type tumours was less refined. The purpose of this study was to assess the expression of glial fibrillary acidic protein (GFAP) in a broad group of both benign and malignant salivary gland tumours. The expression of GFAP was assessed in 99 tumours including 54 PAs, 5 basal cell adenomas, 1 myoepitheliomas, 5 adenoid cystic carcinomas, 6 epithelial-myoepithelial carcinomas (EMCA), 6 mucoepidermoid carcinomas, 7 salivary duct carcinomas, 1 adenocarcinomas NOS, 2 myoepithelial carcinomas, 4 basal cell adenocarcinomas, 5 acinic cell carcinomas and 3 polymorphous adenocarcinomas. Of the malignant cases, 8 were classified as carcinomas ex PA. GFAP was also assessed in 19 concurrent biopsy specimens. GFAP was expressed in the resections of 51 PAs examined (94%). Expression was predominantly strong and diffusely seen in myoepithelial cells. Strong and diffuse GFAP expression was also seen in two EMCAs (33%) and one myoepithelial carcinoma (50%). On biopsy specimens, 100% of PAs and basal cell adenomas expressed GFAP. GFAP was also seen in 1 out of 3 carcinomas ex PAs on biopsies. Almost all PAs show strong and diffuse expression of GFAP. In contrast, most malignant neoplasms that can mimic PA on biopsies show only rare, focal expression. Other benign tumours composed of abluminal/myoepithelial cells also show focal expression of GFAP, highlighting the spectrum these tumours share with PA. Overall, the presence of strong and diffuse GFAP expression can favour a benign neoplasm, specifically a PA, on limited biopsy specimens.

Adenoid cystic carcinoma. An indolent but aggressive tumour. Part A: from aetiopathogenesis to diagnosis

Adenoid cystic carcinoma (ACC) is a relatively rare tumour of the minor and major salivary glands. It is uncommon in the parotid gland while it is much more frequent in the submandibular gland and in minor salivary and mucinous glands (oral cavity, oropharynx, and paranasal sinuses). ACC may also arise in secretory glands located in other tissues, such as in the tracheobronchial tree, oesophagus, breast, lungs, prostate, uterine cervix, lachrymal and Bartholin’s glands, and skin. The natural history of ACC is characterised by an indolent growth rate, a relatively low probability of regional lymph node metastases and a high likelihood of haematogenous dissemination. ACC has been traditionally subdivided into three histological groups (cribriform, tubular, and solid) based on solid components of the tumour. Some studies have shown that tumours with a solid growth component have a rapid fatal course, compared to tumours without a solid growth component, but other studies have failed to correlate growth patterns with clinical course. The purpose of this review is to analyse the very large number of studies (sometimes contradictory) on ACC. In this first part, the aetiology, epidemiology, histopathology, clinical behaviour and diagnostic workup are examined.

Nasopharyngeal Carcinoma Ex Pleomorphic Adenoma: Case Report and Comprehensive Literature Review

Carcinoma ex pleomorphic adenoma (CXPA) is an epithelial malignancy that transforms from benign pleomorphic adenomas (PA) at a rate of 1.5% after 5 years and 10% after 15 years. The average age of reported nasopharyngeal CXPA is 56.7 years. However, the present case describes a 19-year-old making this case exceptionally rare. Standard treatment is wide local excision with adjuvant treatment. We report the demographics, presentation, treatment, and outcomes of 8 cases of nasopharyngeal CXPA. While surgical excision is the mainstay of treatment, negative margins can be difficult to obtain at the skull base, and we report a recurrence rate of 50% in nasopharyngeal primaries. Due to the aggressive nature of the disease and high rate of recurrence, the majority of patients in our review received adjuvant radiation with some receiving adjuvant chemotherapy in addition.

Computed tomography and magnetic resonance imaging of adenoid cystic carcinoma in the maxillary sinus: a retrospective study with radiologic-histopathologic correlations

OBJECTIVE

The aim of this study was to investigate computed tomography (CT) and magnetic resonance imaging (MRI) findings in adenoid cystic carcinoma (ACC) in the maxillary sinus and their correlations with the tubular, cribriform, and solid histopathologic types of ACC.

STUDY DESIGN

Twenty cases of histopathologically proven ACC in the maxillary sinus were retrospectively reviewed. CT and MRI findings were correlated with histopathologic results.

RESULTS

On CT, significant differences were discovered among the 3 histopathologic ACC types in range, size, shape, margins, type of bone destruction, and time intensity curve (TIC) (P ≤ .018). Tubular lesions were limited in range, were smaller than the other types, produced small cystic patterns with well-defined margins, and caused a cribriform pattern of bone destruction. All tumors demonstrated heterogeneous intensity signal on T1- and T2-weighted images (T1WI and T2WI) and appeared as hypo- or isointense small cystic lesions on T1WI and hyperintense on T2WI (n = 6). Postcontrast MRI revealed marked heterogeneous enhancement for all lesions. The TIC showed a rapidly enhancing and slow washout pattern in all tubular lesions and a rapidly enhancing and rapid washout pattern in solid tumors.

CONCLUSIONS

Different histologic patterns of ACCs have distinctive radiologic features, which can facilitate accurate preoperative diagnosis.

Carcinoma ex Pleomorphic Adenoma in the Floor of the Mouth: An Unusual Diagnosis in a Rare Location

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignant salivary gland tumor, mostly involving the parotid and submandibular glands. Minor salivary gland involvement is even rarer, palate being the most common site. Other reported sites are upper lip, sinonasal tract, and buccal mucosa. Here, we report a case of CXPA in an unusual location, the floor of the mouth.

Sinonasal/nasopharyngeal pleomorphic adenoma and carcinoma ex pleomorphic adenoma: a report of 17 surgical cases combined with a literature review

Objective: The aim of this study was to review demographic data, location, clinical symptoms, therapeutic methods, pathological features and relapse in sinonasal/nasopharyngeal pleomorphic adenoma (PA) and carcinoma ex pleomorphic adenoma (CXPA).

Methods: We conducted a retrospective analysis of 17 patients who were referred to our hospital during a 5-year period from 2013 to 2018.

Results: In this series, there were 7 males and 10 females. The tumors originated from the nasal septum in 4 cases, from the lateral wall of the nasal cavity in 2 cases, from the maxillary sinus in 1 case, and from the nasopharynx in 7 cases. The origin sites of 3 cases were not clear. The main symptoms were usually unilateral nasal congestion and epistaxis. All patients underwent endoscopic resection surgery. The postoperative period was uneventful. Ten patients were diagnosed with benign PA, and 7 patients were diagnosed with CXPA, including 5 cases of adenocarcinoma, 1 patient with mucoepidermoid carcinoma, and 1 patient with adenoid cystic carcinoma. After a mean follow-up period of 2.2 years (6 months–5.3 years), the recurrence rate of benign PA was 10% (1/10); the rate of malignant recurrence was 42.8% (3/7).

Conclusion: Sinonasal/nasopharyngeal PA and CXPA are rare neoplasms, and the most common primary site of PA and CXPA is the nasopharynx. As any salivary carcinoma type can arise in PA, these PA sites should be thoroughly sampled and closely examined to exclude the possibility of malignant transformation. Furthermore, PA and CXPA should be treated as soon as possible after definitive diagnosis, and endoscopic resection of tumor-negative margins may be helpful in preventing recurrence.

Intensity-modulated radiotherapy for paranasal sinuses and base of skull tumors

Paranasal sinus and skull base tumors are rare aggressive head and neck cancers, and typically present in the locally advanced stages. As a result, achieving wide surgical resection with clear margins is a challenge for these tumors, and radiotherapy is thus usually indicated as an adjuvant modality following surgery to optimize local control. Given the integral role of radiotherapy in the management of this subgroup of head and neck tumors, the advent of intensity-modulated radiotherapy (IMRT) has led to substantial improvement of clinical outcomes for these patients. This is primarily driven by the improvement in radiation dosimetry with IMRT compared to conventional two dimensional (2D)- and 3D-techniques, in terms of ensuring dose intensity to the tumor target coupled with minimizing dose exposure to critical organs. Consequently, the evident clinical benefits of IMRT have been in reduction of normal tissue toxicities, ranging from critical neurological symptoms to less debilitating but bothersome symptoms of eye infections and radiation-induced skin changes. Another domain where IMRT has potential clinical utility is in the management of a subset of non-resectable T4 paranasal sinus and skull base tumors. For these inoperable lesions, the steep dose-gradient between tumor and normal tissue is even more advantageous, given the crucial need to maintain dose intensity to the tumor. Innovative strategies in this space also include the use of induction chemotherapy for patient selection. In this review, we summarized the data for the aforementioned topics, including specific discussions on the different histologic subtypes of paranasal sinus and skull base tumors.

Cervical lymph node metastasis in adenoid cystic carcinoma of the sinonasal tract, nasopharynx, lacrimal glands and external auditory canal: a collective international review

OBJECTIVE

To review reports of adenoid cystic carcinomas arising in the head and neck area outside of the major salivary glands, in order to enhance the care of patients with these unusual neoplasms.

METHODS

An international team of head and neck surgeons, pathologists, oncologists and radiation oncologists was assembled to explore the published experience and their own working experience of the diagnosis and treatment of adenoid cystic carcinomas arising in the vicinity of the sinonasal tract, nasopharynx, lacrimal glands and external auditory canal.

RESULTS

The behaviour of adenoid cystic carcinoma arising in head and neck sites exclusive of the major salivary glands parallels that of tumours with a similar histology arising in the major salivary glands - these are relentless, progressive tumours, associated with high rates of mortality. Of 774 patients reviewed, at least 41 (5.3 per cent) developed documented regional node metastases.

CONCLUSION

The relatively low overall incidence of nodal metastases in adenoid cystic carcinomas arising in the head and neck region outside of the major salivary glands suggests that routine elective regional lymph node dissection might not be indicated in most patients with these tumours.

Pedunculated carcinoma ex pleomorphic adenoma of the nasal cavity: A unique case report

BACKGROUND

A carcinoma ex pleomorphic adenoma (CXPA) is an epithelial malignancy arising in or from a benign pleomorphic salivary adenoma. The parotid gland is the most common location of CXPAs. Minor salivary gland CXPAs of the nasal cavity are exceedingly rare, with only 6 documented in the literature.

METHODS AND RESULT

We present a 7th case: an unusual pedunculated intranasal CXPA, which had a favorable outcome after a wide endoscopic excision and the longest follow-up period reported to date. The clinical features, immunohistochemical characteristics, treatment choices, and disease outcomes of the intranasal CXPAs reported in previous studies are also reviewed.

CONCLUSION

This case demonstrates the importance of considering the possibility of CXPA in the differential diagnosis of minor salivary gland malignancies in the nasal cavity.

Pleomorphic adenoma in the nasal cavity: a clinicopathological study of ten cases in Finland

The objective of the study was to investigate the nationwide occurrence of sinonasal pleomorphic adenoma in Finland. A retrospective study was conducted at The Departments of Otorhinolaryngology-Head and Neck Surgery, and Pathology at the five university hospitals in Finland. Data were obtained by searching for sinonasal pleomorphic adenoma cases in the clinical and histopathological registries at these institutions for the past two to four decades. All patients who had had a histologically proven pleomorphic adenoma in the sinonasal area were included as participants. Ten cases with pleomorphic adenoma of the nasal cavity were found. The majority of these tumours originated in the septum, and there were no malignant transformations. Pleomorphic adenomas of the nasal cavity were found to be extremely rare in this nationwide investigation.

Nasal Cavity and Paranasal Sinuses

The nasal cavity and paranasal sinuses occupy the top of the upper respiratory tract and form pneumatic spaces connected with the atmosphere. They are located immediately beneath the base of the cranium, where crucial vital structures are harbored. From this region, very much exposed to airborne agents, arise some of the more complex and rare benign and malignant lesions seen in humans, whose difficulties in interpretation make this remarkable territory one of the most challenging in the practice of surgical pathology.

Contents of this chapter cover inflammations and infections, polyps and pseudotumors, fungal and midfacial destructive granulomatous lesions, as well as benign, borderline, and malignant neoplasms. Among the neoplasms, emphasis is made on those entities characteristic or even unique for the sinonasal region, such as Schneiderian papillomas, glomangiopericytoma, intestinal- and non-intestinal-type adenocarcinomas, olfactory neuroblastoma, nasal-type NK-/T-cell lymphoma, and teratocarcinosarcoma. Moreover, recently recognized entities involving this territory, i.e., HPV-related non-keratinizing carcinoma, NUT carcinoma, and SMARCB1-deficient basaloid carcinoma, are also discussed in the light of their specific molecular findings. Furthermore, the text is accompanied by numerous classical and recent references, several tables, and 100 illustrations.

Sinonasal Adenoid Cystic Carcinoma with Intracranial Invasion and Perineural Spread: A Case Report and Review of the Literature

We present the case of a 51-year-old patient with sinonasal adenoid cystic carcinoma (SACC). Computed tomography (CT) and magnetic resonance imaging (MRI) exams revealed an expansive process in the right nostril accompanied with perineural spread and invasion to the floor of the middle cranial fossa. Due to the size of the tumor and brain involvement, the Head and Neck Tumor Board (HNTB) recommended radiochemotherapy treatment to decrease the size of the lesion. Presently, the patient is undergoing treatment without major complications.

Myoepithelial Carcinoma of the Nasopharynx: Report of a Rare Case and a Review of the Literature

Salivary gland carcinomas are very rare in the nasopharynx, with the most frequent histologic types being adenoid cystic carcinoma, mucoepidermoid carcinoma and adenocarcinoma, not otherwise specified. Myoepithelial carcinoma (MECA) is a rare tumor of the salivary glands, and there are only three previously reported cases of nasopharyngeal MECA. The case presented is the fourth reported case of MECA in the nasopharynx. Due to the morphologic heterogeneity of MECA, immunohistochemistry is indispensable in ascertaining the diagnosis. MECA is a locally aggressive tumor, but the long-term prognosis of this tumor in the nasopharynx remains uncertain. In our case the tumor was unresectable and the patient was given chemo-radiotherapy. Despite this, residual tumor was seen on nasoscopy 5 months after initial diagnosis and was documented on a re-biopsy which displayed the same histomorphologic features as the original tumor.

Sinonasal tract and nasopharyngeal adenoid cystic carcinoma: a clinicopathologic and immunophenotypic study of 86 cases

Primary sinonasal tract and nasopharyngeal adenoid cystic carcinomas (STACC) are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. Eighty-six cases of STACC included 45 females and 41 males, aged 12-91 years (mean 54.4 years). Patients presented most frequently with obstructive symptoms (n = 54), followed by epistaxis (n = 23), auditory symptoms (n = 12), nerve symptoms (n = 11), nasal discharge (n = 11), and/or visual symptoms (n = 10), present for a mean of 18.2 months. The tumors involved the nasal cavity alone (n = 25), nasopharynx alone (n = 13), maxillary sinus alone (n = 4), or a combination of the nasal cavity and paranasal sinuses (n = 44), with a mean size of 3.7 cm. Patients presented equally between low and high stage disease: stage I and II (n = 42) or stage III and IV (n = 44) disease. Histologically, the tumors were invasive (bone: n = 66; neural: n = 47; lymphovascular: n = 33), composed of a variety of growth patterns, including cribriform (n = 33), tubular (n = 16), and solid (n = 9), although frequently a combination of these patterns was seen within a single tumor. Pleomorphism was mild with an intermediate N:C ratio in cells containing hyperchromatic nuclei. Reduplicated basement membrane and glycosaminoglycan material was commonly seen. Necrosis (n = 16) and atypical mitotic figures (n = 11) were infrequently present. Pleomorphic adenoma was present in 9 cases; de-differentiation was seen in two patients. Immunohistochemical studies showed positive reactions for pan-cytokeratin, CK7, CK5/6, CAM5.2, and EMA, with myoepithelial reactivity with SMA, p63, calponin, S100 protein and SMMHC. CD117, CEA, GFAP and p16 were variably present. CK20 and HR HPV were negative. STACC needs to be considered in the differential diagnosis of most sinonasal malignancies, particularly poorly differentiated carcinoma, olfactory neuroblastoma and pleomorphic adenoma. Surgery (n = 82), often accompanied by radiation therapy (n = 36), was generally employed. A majority of patients developed a recurrence (n = 52) 2-144 months after initial presentation. Overall mean follow-up was 19.4 years (range 0.4-37.5 years): 46 patients died with disease (mean 6.4 years); 5 were alive with disease (mean 5.4 years), and 35 patients were either alive or had died of unrelated causes (mean 16.3 years). ACC of the SNT is uncommon. Recurrences are common. The following parameters, when present, suggest an increased incidence of either recurrence or dying with disease: mixed site of involvement, high stage disease (stage IV), skull base involvement, tumor recurrence, a solid histology, perineural invasion, bone invasion, and lymphovascular invasion.