Polymorphous Adenocarcinoma Research Articles

Lip Reconstruction by Double Layer and Double Flap New Combination Technique: A Case Series.

In the past, lip reconstruction after ablative surgery has been performed by primary closure and more recently by free flap transfer technique. Cheek’s skin flap has been used to reconstruct the lower lip cutaneous portion. This study presents a reconstructive method for the vermillion and the lip’s cutaneous portion using the Goldstein–Robotti techniques (for the vermillion) and the buccinator flap to reconstruct the cutaneous lip portion and the perioral muscles. This procedure allows a complete reconstruction with a double layer technique for defects of more than one-third of both lips, together or alone, including modiolus, showing satisfactory functionality and aesthetics. The procedure was carried out by splitting the buccinator muscle and elongating the upper and lower buccinator bundles, together or alone. Soft tissue blunt dissection prevented most facial nerves and vessels injuries, ensuring blood supply and an amount of lip sensitivity. Even in the case of facial vessel ligatures after neck dissection, the technique was possible basing the flap pedicle on the internal maxillary artery branches (buccinator) and contralateral facial vessels (orbicularis). We present a case series of six reconstructions of various defects of the upper and lower lips, including the commissure after ablative surgery for squamous cell carcinoma and polymorphous adenocarcinoma. The results showed satisfactory functional and aesthetic outcomes, with similar tissue texture, static and dynamic symmetry achieved for all the patients.

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.

Polymorphous adenocarcinoma of the parotid – An uncommon site of occurrence

Polymorphous low-grade adenocarcinoma is a neoplasm of the minor salivary glands and is malignant in origin but is indolent in nature. Currently, this neoplasm is documented and known as polymorphous adenocarcinoma (PAC) by WHO Classification of Salivary Gland Tumors (2017). Of all the salivary neoplasms, minor salivary gland neoplasm accounts for 9%–23%. Very rarely, it involves major salivary glands such as parotid, submandibular, and sublingual in <5% cases. It may develop either de novo or from pleomorphic adenoma. PAC mimics some benign as well as malignant neoplasms. Histopathological features alone cannot diagnose PAC due to the overlapping features with other neoplasms, and so immunohistochemistry is essential to confirm the diagnosis and hence aids in the proper management of PAC. We report a case of PAC arising from parotid gland in a 52-year-old male treated with facial nerve preservation.

Expression of Ki-67, P63, P40, and alpha-smooth muscle actin in salivary gland carcinomas with or without myoepithelial differentiation

Background: Myoepithelial cells are involved in the development of salivary glands. Many studies propose that these cells can prevent cell proliferation. Aim: This study aimed to investigate the expression of Ki-67, P63, P40, and alpha-smooth muscle actin (α-SMA) in salivary gland carcinomas with or without myoepithelial differentiation. Methods: A panel of myoepithelial markers including P63, P40, α-SMA, and Ki-67 were used for immunohistochemical study in 67 salivary gland carcinomas (33 with and 34 without myoepithelial differentiation). The percentage of positive cells was calculated (in high-power field) from a minimum of 1000 neoplastic cells. SPSS software (version 21) was used. Results: There was no statistically significant difference between Ki-67 expression and the presence or absence of myoepithelial cells (P = 0.6), but Ki-67 expression was related to the age (P = 0.032) and location of carcinomas (P = 0.001). All carcinomas with myoepithelial differentiation exhibited consistent P63+/P40+ staining, whereas polymorphous adenocarcinomas showed P63+/P40− immunophenotype. The expression of Ki-67 in adenoid cystic carcinomas was higher than mucoepidermoid carcinomas (P = 0.020) and polymorphous adenocarcinomas (P = 0.002). Conclusion: In the present study, although the decrease in the number of myoepithelial cells was associated with increased proliferation in adenoid cystic carcinomas, no such relationship was found in the overall assessment between the two groups. This can be justified by the fact that the clinical behavior of salivary carcinomas and their cell proliferation may be affected by factors other than the presence of myoepithelial cells or lack thereof. Ki-67 and P63/P40 expressions may be useful to differentiate adenoid cystic carcinomas from polymorphous adenocarcinomas in small biopsies.

Polymorphous adenocarcinoma of the palate

Introduction: Polymorphous adenocarcinoma (PAC) is a malignant tumour which arises mainly from the minor salivary glands. According to the literature review PAC is the second most common intra oral malignant minor salivary gland tumour.

Histopathological and Immunohistochemical Analysis of Rare Parotid Tumours: A Case Series

Malignant salivary gland tumours are rare representing only 2% of all head and neck malignancies. The most common malignant salivary gland tumour is mucoepidermoid carcinoma followed by adenoid cystic carcinoma while parotid is the most common site. But there are presence of other rare variants with diverse biological feature of maliganacy including Salivary Duct Carcinoma (SDC), basal cell adenocarcinoma, Carcinoma ex Pleomorphic Adenoma (CXPA), polymorphous adenocarcinoma which represent 1-5% of all salivary gland neoplasm. They typically are high-grade carcinomas with presence lymph nodal metastases. Hereby, author report 5 rare cases of parotid gland malignancy detected by histopathological examination along with confirmation by immunohistochemical examination. A 60-year-old and 65-year-old male diagnosed with salivary duct carcinoma of left parotid and right parotid respectively with ipsilateral cervical lymph node involvement but peripheral resection margins were free from tumour invasion. A 50-year-old female diagnosed with basal cell adenocarcinoma of left parotid with lymph node metastasis and resection margin was involved by the tumour. A 60-year-old male presented with recurrent swelling in left parotid region, diagnosed as carcinoma ex pleomorphic adenoma with lymph node involvement in a case of pleomorphic adenoma of parotid, reported previously. A 52-year-old male presented with right-sided parotid region swelling for last six months having Fine Needle Aspiration Cytology (FNAC) report of pleomorphic adenoma. Parotidectomy revealed diagnosis of polymorphous adenocarcinoma while surgical resection margins were free. Surgery is the main mode of treatment in these tumours. Involvement of resection margins, extraparotid extension, lymphovascular and perineural invasion along with lymph node metastasis are the common indicator for postoperative radiation therapy.

Morphological spectrum of salivary gland tumors withspecial reference to mucin stains

Salivary gland neoplasm are rare and constitute about 3% of all head and neck neoplasms. Mucins are altered in pathological states and are stained by special stains like Periodic Acid Schiff, Alcian Blue and Mucicarmine. To study the histomorphology of resected salivary gland tumors and mucin staining pattern wherever indicated. Surgically resected specimens received at our tertiary care hospital and subjected to histopathological examination. Specimens were fixed in 10% formalin, processed and embedded in paraffin blocks, serially cut to get sections of 3-5 microns thickness. Stained with hematoxylin and eosin for all. Mucin stains were used wherever applicable. Total number of cases studied were 70. Out of which 46 were benign (65.7%) and 24 were malignant (34.3%). Among benign tumours, Pleomorphic adenoma was the commonest tumour (48.57), followed by Warthin tumor (7.14%), Basal cell adenoma (4.28%), Myoepithelioma (1.43%), Oncocytoma (1.43%), Hemangioma (1.43%), Sailolipoma (1.43%). The Mucoepidermoid carcinoma was the most common malignant tumor (17.14%) followed by Adenoid cystic carcinoma (5.71%), Acinic cell carcinoma (4.28%), Polymorphous adenocarcinoma (1.43%), Epithelial myoepithelial carcinoma, Squamous cell carcinoma (1.43%), Salioblastoma (1.43%), Lymphoma (1.43%). Parotid was most common site for both benign and malignant tumor. Females are affected more commonly than males. Mucin staining pattern was noted. Salivary gland tumors have complex range of morphological spectrum. Histopathological examination is the golden standard for diagnosis and mucin stain would add as an adjunct to the diagnosis.

Sclerosing Microcystic Adenocarcinoma: A Case Report and Review of Literature

Abstract Sclerosing microcystic adenocarcinoma is an extremely rare tumor that was described by Mills et al in 2016 and occurs in the head and neck region. There are 8 cases published with this terminology in the English language literature. Here, we present a 59-year-old female patient with sclerosing microcystic adenocarcinoma in the anterolateral tongue and review the previously reported 8 cases. Most of the reported cases are in females and localized to the tongue. This tumor mimics microcystic adnexal carcinoma, which is a cutaneous-based malignant tumor. The tumor in the present case was composed of cells that were arranged in nests or gland-like structures, with had ductular differentiation in a densely sclerotic stroma. The diagnosis of sclerosing microcystic adenocarcinoma may be difficult because of its paucicellular histomorphology. Surgical margins can be problematic to assess. Several salivary gland tumors should be included in the differential diagnosis, such as adenoid cystic carcinoma, polymorphic adenocarcinoma, and mucoepidermoid carcinoma. The role of immunohistochemistry in this differential diagnosis is limited. Therefore, the diagnosis depends on routine histology.

Polymorphous Adenocarcinoma of Lacrimal Gland: A Rare Case Report

Polymorphous adenocarcinoma is a slow growing malignant tumor of minor salivary glands. The most common location of these tumors is palate, buccal mucosa, upper lip, floor of mouth and retromolar region. This malignant neoplasm is characterized by cytological uniformity, architectural diversity and infiltrative growth pattern. This is a case report of polymorphous adenocarcinoma occurring in lacrimal gland. They are seldom reported in this location and propose unique diagnostic challenges.

Classic polymorphous adenocarcinoma: Fine needle aspiration cytopathology of eight cases.

The cytopathology and diagnostic accuracy of salivary gland (SG) polymorphous adenocarcinoma (PAC) is the subject of a limited number of reports. We undertook a review of our experience with fine needle aspiration (FNA) biopsy and PAC. A search was made of our cytopathology files for PAC cases that also had histopathological confirmation. FNA biopsy smears and cell-blocks were performed and examined using standard techniques. Eight FNA biopsy cases of histologically proven PAC from 7 patients [F:M=1.3:1, age 39-75years, mean=58] met study inclusion. Metastatic aspirates were most common (4), followed by 3 primary cases and 1 locally recurrent neoplasm. Primary FNA sites included hard palate (1 case), lip (1), and lateral tongue (1); all metastatic sites were in the neck. A precise cytologic diagnosis was made in 38% of cases; however, when applying the Milan classification system, 100% could be categorised as either malignant or of uncertain malignant potential. Ancillary immunohistochemical testing performed in 44% of the cases was non-specific. Cytologic smears showed cellular uniformity and structural variety of cell groups with tubular, branching, cribriform, and convex patterns as well as variable, but occasionally abundant globular myxoid stroma leading to confusion with adenoid cystic carcinoma. The imitative cytopathology of PAC with other SG neoplasms as well as its infrequency in routine FNA biopsy practice makes specific interpretation difficult, but using a classification system allows for appropriate patient management. Molecular testing in future specimens holds promise for enhancing diagnostic accuracy.

SALIVARY MICROSECRETORY ADENOCARCINOMA - CASE REPORT OF A RECENTLY DESCRIBED ENTITY

<h3>Clinical Presentation</h3> A 35-year-old female patient presented with a 1.5-cm left hard palate swelling. The incisional biopsy was inconclusive, and imaging suggested a nonaggressive lesion with no evidence of bone invasion. The lesion was excised and sent for histopathologic examination. <h3>Histology</h3> Histologic examination showed a well-defined and unencapsulated multilobular lesion within the connective tissue exhibiting morphological diversity with areas of ductal differentiation, prominent cytoplasmic clearing, and areas with an eosinophilic and epithelioid appearance. In places, cords and trabeculae of tumor cells with a prominent microcystic appearance were seen with surrounding fibromyxoid stroma. Focally, the tumor cells showed a spindled and somewhat infiltrative appearance, but there was no evidence of single-cell filing or perineural or lymphovascular invasion. <h3>Further Investigations</h3> Immunohistochemistry showed diffuse staining for CK7, Cam5.2, and S100 with p63 staining in a significant proportion of the tumor cells. There was no evidence of a biphasic population, and other myoepithelial markers (i.e., calponin and p40) were also negative. Ki67 staining showed a low proliferation index of approximately 5%. Targeted RNA sequencing showed the presence of <i>MEF2C-SS18</i> gene fusion, leading to a definitive diagnosis of salivary microsecretory adenocarcinoma (MA). <h3>Discussion</h3> Salivary MA is a recently described entity characterized by the <i>MEF2C-SS18</i> gene fusion. The differential diagnosis includes an adenocarcinoma not otherwise specified, and the immunohistochemical profile is similar to a polymorphous adenocarcinoma; however, both of these entities lack the characteristic molecular signature. Only 5 cases of MA have been reported to date, with our case adding to the existing literature on this emerging entity.

Polymorphous adenocarcinoma transforming to Adenoid cystic carcinoma - A case report

Polymorphous adenocarcinoma is an indolent salivary gland carcinoma characterized by cytologic uniformity and architectural diversity, predominantly affecting minor salivary glands, in particular the hard and soft palate. Adenoid cystic carcinoma (ACC) is an uncommon type of adenocarcinoma, a kind of malignant growth that starts in glandular tissues. It most regularly emerges in the major and minor salivary organs of the head and neck. This paper reports an instance of a 59-year-old male patient who was determined to have Polymorphous adenocarcinoma which ultimately ended up being Adenoid cystic carcinoma.

SalvGlandDx – a comprehensive salivary gland neoplasm specific next generation sequencing panel to facilitate diagnosis and identify therapeutic targets

Diagnosis of salivary gland neoplasms is often challenging due to their high morphological diversity and overlaps. Several recurrent molecular alterations have been described recently, which can serve as powerful diagnostic tools and potential therapeutic targets (e.g. NTRK or RET fusions). However, current sequential molecular testing can be expensive and time consuming. In order to facilitate the diagnosis of salivary gland neoplasms, we designed an all-in-one RNA-based next generation sequencing panel suitable for the detection of mutations, fusions and gene expression levels (including NR4A3) of 27 genes involved in salivary gland neoplasms. Here we present the validation of the “SalvGlandDx” panel on FFPE histological specimen including fine needle aspiration (FNA) cell block material, against the standard methods currently used at our institution. In a second part we describe selected unique cases in which the SalvGlandDx panel allowed proper diagnosis and new insights into special molecular characteristics of selected salivary gland tumors. We characterize a unique salivary gland adenocarcinoma harboring a ZCCHC7-NTRK2 fusion, a highly uncommon spindle cell and pseudoangiomatoid adenoid-cystic carcinoma with MYBL1-NFIB fusion, and a purely oncocytic mucoepidermoid carcinoma, whereas diagnosis could be made by detection of a CRTC3-MAML2 rearrangement on the cell block specimen of the FNA. Further, a rare case of a SS18-ZBTB7A rearranged low-grade adenocarcinoma previously described as potential spectrum of microsecretory adenocarcinoma, is reported. In addition, features of six cases within the spectrum of polymorphous adenocarcinoma / cribriform adenocarcinoma of salivary gland including PRKD1 p.E710D mutations and novel fusions involving PRKAR2A-PRKD1, SNX9-PRKD1 and ATL2-PRKD3, are described.

Immunohistochemical Expression of Fatty Acid Synthase (FASN) is Correlated to Tumor Aggressiveness and Cellular Differentiation in Salivary Gland Carcinomas.

Fatty acid synthase (FASN) expression is closely related to cancer progression, in particular, tumor aggressiveness and poor prognosis. This study aimed to analyse the expression of FASN in carcinomas of the salivary glands and correlate it with Ki-67 expression. We analysed by immunohistochemistry the expression of FASN and Ki-67 on tissue sections from 7 cases of adenocarcinoma, not otherwise specified (AdNOS), 6 cases of polymorphous adenocarcinoma (PAC), 16 cases of acinic cell carcinoma (AcCC), 19 cases of adenoid cystic carcinoma (AdCC), 15 cases of epithelial-myoepithelial carcinoma (EMC); 10 cases of secretory carcinoma (SC), 13 cases of mucoepidermoid carcinoma (MEC), 10 cases of salivary ductcarcinoma (SDC) and 7 cases of myoepithelial carcinoma (MC). These carcinomas were classified into aggressive and indolent regarding their biological behaviour. Additionally, MEC and AdCC were also classified according to the histological grade. High expression of FASN was found in SDC (100%), SC (100%), AcCC (68.7%) and AdNOS (57.2%). No association was found between FASN and Ki-67 expression. Aggressive carcinomas showed a higher rate of Ki-67 proliferation (p < 0.001) and greater expression of FASN when compared to indolent carcinomas (p < 0.05). With regards to carcinomas categorized as indolent, FASN expression was much higher in the lesions that presented cell differentiation (SC and AcCC). Also, FASN expression was significantly higher in high-grade AdCC and MEC when compared to low-grade tumors (p < 0.05). We concluded that FASN expressionwas correlated to tumor aggressiveness and cellular differentiation in salivary gland carcinomas.

CRIBRIFORM ADENOCARCINOMA OF MINOR SALIVARY GLANDS: A CASE REPORT WITH FOCUS ON RADIOGRAPHIC APPERANCE

Cribriform adenocarcinoma of minor salivary gland (CAMSG) is currently classified as a subtype of polymorphous adenocarcinoma. CAMSG differs from polymorphous adenocarcinoma in that it has a distinct histopathologic appearance and clinically CAMSG has higher rate of lymph node metastasis at initial presentation. Panoramic radiograph shows an ill-defined radiolucent lesion in the right maxilla that extends from the distal of maxillary right canine to the mesial of maxillary second molar. The lesion has invasive borders and causes destruction and loss of the lamina dura and periodontal ligament space in the mesial of the second molar and distal of the canine. The lesion has also invaded into the right maxillary sinus destroying the floor of sinus. CBCT images show a low attenuation lesion involving the right maxillary alveolar bone at the premolars and first molar area. This report describes the radiographic appearance of a case of CAMSG on panoramic radiograph, cone-beam computed tomography (CBCT), multi-detector computed tomography (MDCT) and on magnetic resonance imaging (MRI).

High-grade Transformation/Dedifferentiation in Salivary Gland Carcinomas: Occurrence Across Subtypes and Clinical Significance.

High-grade transformation (HGT) or dedifferentiation has been described in a variety of salivary gland carcinomas, including acinic cell carcinoma, secretory carcinoma, adenoid cystic carcinoma, epithelial-myoepithelial carcinoma, polymorphous adenocarcinoma, low-grade mucoepidermoid carcinoma, and hyalinizing clear cell carcinoma. High-grade (HG) transformed tumors are composed of a conventional low-grade component characterized by specific microscopic and immunohistochemical features for the given entity, intermingled with or juxtaposed to areas of HG morphology. This is usually either poorly differentiated adenocarcinoma, carcinoma not otherwise specified, or undifferentiated carcinoma, in which the original line of differentiation is lost. The HG component is composed of solid nests of anaplastic cells with large vesicular pleomorphic nuclei, prominent nucleoli, and abundant cytoplasm. Frequent mitoses and extensive necrosis may be present. The Ki-67 labeling index is consistently higher in the HG component. The molecular genetic mechanisms responsible for HGT of salivary gland carcinomas are largely unknown, though p53 inactivation and human epidermal growth factor receptor 2 overexpression and/or gene amplification have been demonstrated in the HG component in a few examples, the frequency varies for each histologic type. Salivary gland carcinomas with HGT are more aggressive than conventional carcinomas, with a higher local recurrence rate and a poorer prognosis. They have a high propensity for cervical lymph node metastasis suggesting a need for a wider resection and neck dissection. HGT of salivary gland carcinoma can occur either at initial presentation or less commonly at the time of recurrence, sometimes following postoperative radiotherapy. The potential for HGT in almost any type of salivary gland carcinoma warrants a thorough sampling of all salivary gland malignancies to prevent oversight of a HG component.

The potential of somatostatin receptor 2 as a novel therapeutic target in salivary gland malignant tumors.

Treatment regimens for patients with metastatic or recurrent post-radiation, locoregional, unresectable salivary cancer are limited. An inverse correlation between somatostatin receptor 2 (SSTR2) and the proliferating marker Ki-67 in neuroendocrine tumors has enabled a treatment plan for metastatic disease, utilizing peptide receptor radionuclide therapy. Interestingly, healthy salivary glands express high levels of SSTR2. In this study, the presence of SSTR2, its correlation with Ki-67 in glandular salivary carcinomas and the clinical applicability thereof was determined. In the retrospective part of this study, 76 adequate tumor tissue specimens obtained from patients diagnosed with primary or metastatic salivary carcinomas between 1988 and 2016, were collected for tissue array and histologically classified. Immunohistochemistry was performed to determine the presence, relative expression and potential correlation of SSTR2 and Ki-67. The clinical significance of SSTR2 expression was determined by prospectively assessing 68Ga-DOTATATE uptake using PET-CT imaging, in patients diagnosed with metastatic salivary gland malignant tumors between 2015 and 2016. Sixty-three primary cancer tumors and 14 metastatic tumors were tested. All tumor subtypes were found to express SSTR2 to some extent. The highest expression was seen in Mucoepidermoid carcinoma (MEC) tissues where the majority of specimens (86.4%) expressed SSTR2. A relatively strong immunohistochemical staining score for SSTR2 was observed in MEC, adenoid cystic carcinoma and polymorphous adenocarcinoma. Interestingly, an inverse correlation between SSTR2 and Ki-67 expressions was observed (44%) in MEC tissue. Uptake of 68Ga-DOTATATE was visualized using PET-CT imaging in 40% of patients, across metastatic MEC and ACC. All observations were found to be statistically significant. This study confirms the expression of SSTR2 in glandular salivary carcinomas and an inverse correlation in expression levels between SSTR2 and Ki-67. This lays a foundation for novel treatment options in salivary metastatic cancers where SSTR2 may be a potential novel therapeutic target.

SS18 Break-Apart Fluorescence In Situ Hybridization is a Practical and Effective Method for Diagnosing Microsecretory Adenocarcinoma of Salivary Glands.

Molecular analysis has allowed for refinement of salivary gland tumor classification and, in some cases, the recognition of entirely new tumor types. Microsecretory adenocarcinoma (MSA) is a salivary gland tumor described in 2019 characterized by microcystic growth, bland cytomorphology, luminal secretions, fibromyxoid stroma, and S100/p63 positivity with negative p40. Most important, MSA is defined by MEF2C-SS18 fusion. While this fusion has, to this point, been detected by next-generation sequencing, this is a technique that is currently inaccessible in most diagnostic laboratories. On the other hand, SS18 break-apart fluorescence in situ hybridization (FISH) is widely available and frequently used as an adjunct for diagnosing synovial sarcoma. It is not known if SS18 break-apart FISH is positive in tumors with MEF2C-SS18, or if it is entirely specific for MSA.Break apart FISH for SS18 was performed on 4 cases of MSA, as well as 8 tissue microarrays (TMAs) containing 423 various salivary gland carcinomas: 26 acinic cell carcinomas, 35 adenocarcinomas not otherwise specified, 96 adenoid cystic carcinomas, 3 basal cell adenocarcinomas, 20 epithelial-myoepithelial carcinomas, 15 hyalinizing clear cell carcinomas, 3 intraductal carcinomas, 12 myoepithelial carcinomas, 117 mucoepidermoid carcinomas, 30 polymorphous adenocarcinomas, 45 salivary duct carcinomas, 19 secretory carcinomas, and 2 undifferentiated carcinomas. SS18 break-apart FISH was also performed on whole slides of 2 tumors from the TMAs.All MSA cases demonstrated classic split patterns on SS18 break-apart FISH. On the TMAs, 374 cases were evaluable by FISH, and 372 cases were clearly negative for SS18 rearrangement. Two cases, both mucoepidermoid carcinomas, had rare split signals below the positivity threshold of 12% on their TMA cores, so FISH was performed on whole sections. On the whole sections both tumors were unequivocally negative for SS18 rearrangement. Taken together, SS18 break-apart FISH was 100% sensitive and 100% specific for a diagnosis of MSA.SS18 break-apart FISH, a diagnostic tool widely available in pathology laboratories, appears to be a highly accurate method for diagnosing MSA of salivary glands. Accordingly, this new tumor type may be molecularly confirmed without needing to resort to highly specialized techniques like next-generation sequencing.

Role of elective neck dissection and adjuvant radiation therapy in patients with polymorphous adenocarcinoma.

To evaluate the role of elective neck dissection (END) and of adjuvant radiation (aRT) in polymorphous adenocarcinoma (PAC), previously known as polymorphous low-grade adenocarcinoma (PLGA). Retrospective cohort study of patients in the National Cancer Database with a histology of PAC (coded as PLGA) at a head and neck site diagnosed between 2004 and 2015. Multivariable Cox proportional hazard modeling was used to assess overall survival in the overall population, and in sub-analyses of clinically N0 disease, positive resection margins, and late stage disease. A total of 922 patients [66.8% female; mean (SD) age, 60.9 (13.9) years] met inclusion criteria. 74.7% of patients received surgery alone, and 18.0% received surgery and aRT. Only 7.6% of patients with clinically N0 disease received an END, with 10.6% of these having at least one positive node. END did not have a survival benefit compared to no END [HR 1.28 (0.61-2.68)]. Compared to surgery alone, aRT did not have significantly increased survival in the overall population or in late stage [HR 0.68 (0.39-1.19) and HR 0.46 (0.18-1.22), respectively]. On sub-analysis of patients with positive resection margins, aRT had a significant survival benefit compared to surgery alone [HR 0.37 (0.14-0.99)]. PAC is a rare, slow-growing malignant tumor typically treated with surgical excision, with undefined indications for END or aRT. Our findings show END to not have a benefit to overall survival. In patients with positive resection margins, there was a survival benefit for aRT.

Polymorphous adenocarcinoma on the base of tongue: a rare case

Polymorphous adenocarcinoma (PAC) is a distinct neoplasm of the minor salivary gland. Most patients present with an asymptomatic mass in the hard palate.” Rarely, “the mass can also occur in the” base of the tongue. A 56-year-old female patient, presented to ENT clinic, Teaching Hospital Jaffna with a history of voice change for 4 months. Her physical examination revealed fissured tongue, a mass of 1×1.5 cm in size with intact mucosa located at the left side of the base of tongue, which was crossing the midline and infiltrated into the deep tongue muscles. Deep biopsy revealed polymorphous adenocarcinoma. She was treated with radiotherapy. PAC is ‘unusual’ to arise at the base of the tongue. It is important to diagnose and treat it accordingly.