Cribriform adenocarcinoma of minor salivary glands may express galectin-3, cytokeratin 19, and HBME-1 and contains polymorphisms of RET and H-RAS proto-oncogenes

Cribriform adenocarcinoma of the minor salivary glands: a case report

BACKGROUND

Polymorphous adenocarcinoma is the third most common malignant salivary gland tumor. Within polymorphous adenocarcinoma, cribriform adenocarcinoma of salivary glands is a rare subtype and resembles papillary thyroid carcinoma histopathologically. Diagnostically, cribriform adenocarcinoma of salivary glands is challenging for pathologists and surgeons alike as initial presentation and cytologic nuclear features can be easily confused with papillary thyroid carcinoma arising from a thyroglossal duct remnant or lingual thyroid.

CASE PRESENTATION

A healthy 64-year-old Caucasian woman presented to a community otolaryngologist with a 4-year history of progressive postnasal drip, globus sensation, and eventual dysphonia. Flexible fiberoptic laryngoscopy showed a large, smooth, vallecular lesion filling the oropharynx. Computed tomography imaging of the neck showed a rounded heterogeneous mass centered within the right aspect of the oropharynx measuring 4.2 × 4.4 × 4.5 cm. Fine needle aspiration biopsy was suspicious for papillary carcinoma due to microscopic findings of malignant cells, nuclear grooves, and a powdery chromatin pattern. In the operating room, the tumor was resected en bloc using a lateral pharyngotomy approach with partial resection of the right lateral hyoid. A limited cervical lymphadenectomy was performed to facilitate the lateral pharyngotomy approach and two out of three lymph nodes demonstrated regional metastatic disease. Nuclear grooves, nuclear membrane notching, and occasional intranuclear pseudoinclusions were identified, which are overlapping histopathological characteristics of papillary thyroid carcinoma and cribriform adenocarcinoma of salivary glands. It was negative for thyroglobulin and thyroid transcription factor-1, which was in keeping with cribriform adenocarcinoma of salivary glands rather than papillary thyroid carcinoma.

CONCLUSION

It is difficult to distinguish cribriform adenocarcinoma of salivary glands from papillary thyroid carcinoma solely by cytology, and the distinct characteristics of regional lymph node metastasis coupled with nuanced histologic differences should be emphasized in the evaluation of patients presenting with neck lymphadenopathy and an unknown primary or tongue mass. If sufficient fine needle aspiration biopsy material is available, thyroid transcription factor-1, thyroglobulin, or molecular testing may prove useful in differentiating cribriform adenocarcinoma of salivary glands from papillary thyroid carcinoma. A misdiagnosis of papillary thyroid carcinoma may lead to inappropriate treatment including unnecessary thyroidectomy. Therefore, it is critical for both pathologists and surgeons to be aware of this uncommon entity to avoid misdiagnosis and subsequent mismanagement.

Unusual presentation of cribriform adenocarcinoma of salivary glands: A case report

According to the last edition of the World Health Organization classification, cribriform adenocarcinoma of salivary glands (CASGs) was considered a variant of polymorphus adenocarcinoma although many authors proposed CASG as a distinct neoplasm. The aim of this study was to report an unusual presentation of CASG in the buccal mucosa of a 63-year-old male patient that showed signs of encapsulation and no evidence of lymph node metastasis. The lesion was composed of lobules of tumoral cells arranged in solid nests, sheets, papillary, and cribriform or glomeruloid patterns. Most of the peripheral cells show palisaded arrangement with peripheral clefting from the adjacent stroma. Surgical resection of the lesion was done and further neck dissection was recommended.

Cribriform adenocarcinoma of the tongue with cervical lymph nodes involvement: Report of an extremely rare tumor and focus about differential diagnosis with polymorphous adenocarcinoma

Cribriform adenocarcinoma is a rare tumor that arise in tongue and minor salivary glands. Previously, only 56 case have been described. In this paper, we report a case of a 83-year-old man and we focus about the differential diagnosis with polymorphous adenocarcinoma.

Cribriform adenocarcinoma of the tongue and minor salivary glands: a systematic review of an uncommon clinicopathological entity

INTRODUCTION

Cribriform adenocarcinoma of the tongue and minor salivary glands (CATMSG) is a rare neoplasm, accounting for less than 1% of salivary gland tumors. In the past it has been considered a possible variant of polymorphous low-grade adenocarcinoma (PLGA), while nowadays it is accepted as a provisional entity in the WHO classification. The aim of this paper is to systematically review the existing literature about CATMSG with a particular attention to differential diagnosis and prognostic factors.

METHODS

This study was performed in accordance with the PRISMA checklist. A comprehensive search in PubMed, Cochrane, and Google Scholar databases was carried out in June 2021, in partnership with a medical librarian, without time restriction. Search items include the following keywords: "cribriform adenocarcinoma of the tongue" OR "cribriform adenocarcinoma of the tongue and minor salivary glands."

RESULTS

A total of 56 patients were evaluated. Patient age across the studies ranged from 13 to 85 years (mean 59.6 year). The most common site of involvement was the tongue (58.9%), followed by palate (19.6%), tonsil (7.1%), buccal (3.6%) and reticular mucosa (3.6%), lip (3.6%), retromolar pad (1.7%), and floor of the mouth (1.7%). Lymph node involvement at the diagnosis was very common (58.9%), while there was no evidence of patients diagnosed with metastatic disease. The most common surgical approach was surgical excision (17, 30.3%); neck dissection was performed in 16 patients (28%). Radiotherapy was the most common adjuvant treatment reported (46.4%); only one patient underwent adjuvant chemotherapy (1.7%). Five patients experienced a recurrence (8.8%).

CONCLUSION

To our knowledge, only 56 five cases of CATMSG have been previously described. The results of this review seem to confirm the low frequency of relapses and distant metastases, but we observed that almost 60% of cases presented with cervical lymph node involvement. In our opinion, CATMSG should be considered as a distinct tumor entity from PLGA.

How Increased Nodal Metastasis and Recurrence in Cribriform Adenocarcinoma Relate to Polymorphous Adenocarcinoma and Survival: A Systematic Review

BACKGROUND

Recently, histologic grade was removed from salivary tumor nomenclature by the WHO to include disease of higher grade. One such entity, cribriform adenocarcinoma (CAC), is an aggressive group of polymorphous adenocarcinoma (PAC), with frequent nodal metastasis and locoregional recurrence. We aim to examine the biologic behavior of this disease as compared with the PAC general cohort inclusive of all subtypes.

METHODS

A systematic review of the literature on polymorphous adenocarcinoma and cribriform adenocarcinoma was completed. A descriptive analysis was performed for the following predictor variables: nodal and distant metastasis, in addition to recurrence. The outcome variables, disease free recurrence, and disease specific survival, where plotted using Kaplan-Meier curves.

RESULTS

PAC and CAC both show median age of diagnosis in the sixth decade of life and a female predominance. CAC occurs most frequently in the tongue and PAC in the palate. The 2 groups show a similar biologic behavior in regards to incidence of distant metastasis (4.1 vs 5.5%), recurrence (12.5 vs 17.8%), and death from disease (3 vs 2.7%). However, there was an increased incidence of nodal metastasis in CAC (53%) as compared with that in PAC of all subtypes (14%).

CONCLUSIONS

CAC exhibits more aggressive biologic behavior as compared with the PAC cohort. Although CAC is not an officially recognized entity, these tumors likely comprise a significant portion of the cases of PAC with poor outcomes and are deserving of attention and consideration for escalation in oncologic treatment.

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.

Polymorphous Adenocarcinoma

Polymorphous adenocarcinoma (PAC) is typically originated from the minor salivary glands and is characterized by cytology uniformity and architectural diversity. PAC commonly harbors PRKD1 E710D mutation. PAC has an excellent prognosis. However, greater than or equal to 10% papillary or greater than or equal to 30% cribriform pattern is an independent adverse prognostic factor. Cribriform adenocarcinoma of salivary gland (CASG) is a controversial entity that is considered within the same histologic spectrum of PAC in current classification schemes; however, it is regarded by some pathologists as a separate entity. CASG shows a propensity to base of tongue location, a lobulated growth pattern, a predominant solid/cribriform architecture, and a high frequency of PRKD1/2/3 fusion.

Histologic Classification and Molecular Signature of Polymorphous Adenocarcinoma (PAC) and Cribriform Adenocarcinoma of Salivary Gland (CASG): An International Interobserver Study

Polymorphous adenocarcinoma (PAC) shows histologic diversity with streaming and targetoid features whereas cribriform adenocarcinoma of salivary gland (CASG) demonstrates predominantly cribriform and solid patterns with glomeruloid structures and optically clear nuclei. Opinions diverge on whether CASG represents a separate entity or a variant of PAC. We aimed to assess the level of agreement among 25 expert Head and Neck pathologists in classifying these tumors. Digital slides of 48 cases were reviewed and classified as: PAC, CASG, tumors with ≥50% of papillary architecture (PAP), and tumors with indeterminate features (IND). The consensus diagnoses were correlated with a previously reported molecular alteration. The consensus diagnoses were PAC in 18/48, CASG in16/48, PAP in 3/48, and IND in 11/48. There was a fair interobserver agreement in classifying the tumors (κ=0.370). The full consensus was achieved in 3 (6%) cases, all of which were classified as PAC. A moderate agreement was reached for PAC (κ=0.504) and PAP (κ=0.561), and a fair agreement was reached for CASG (κ=0.390). IND had only slight diagnostic concordance (κ=0.091). PAC predominantly harbored PRKD1 hotspot mutation, whereas CASG was associated with fusion involving PRKD1, PRKD2, or PRKD3. However, such molecular events were not exclusive as 7% of PAC had fusion and 13% of CASG had mutation. In conclusion, a fair to moderate interobserver agreement can be achieved in classifying PAC and CASG. However, a subset (23%) showed indeterminate features and was difficult to place along the morphologic spectrum of PAC/CASG among expert pathologists. This may explain the controversy in classifying these tumors.

Histologic spectrum of polymorphous adenocarcinoma of the salivary gland harbor genetic alterations affecting PRKD genes

Polymorphous adenocarcinoma (PAC) and cribriform adenocarcinoma of (minor) salivary gland (CASG) are salivary gland tumors with overlapping spectrum of morphology. Whether these represent distinct entities or a histologic spectrum of the same tumor remains contentious. PACs harbor recurrent PRKD1 E710D hotspot mutations in >70% of cases, whereas 80% of CASGs display rearrangements involving PRKD1, PRKD2, or PRKD3 (PRKD1/2/3). We studied the molecular and morphologic features of 37 PACs/CASGs, seeking to identify the associations among genotype, histologic phenotype, and classification. DNA was subjected to Sanger sequencing analysis of the PRKD1 hotspot locus. Fluorescence in situ hybridization (FISH) analysis for PRKD1/2/3 was performed using dual-color break-apart probes. Tumors were classified into four categories as described previously: PAC, CASG, tumor with indeterminate features (TIF), and tumor with a predominant papillary pattern (TPPP). PRKD1 E710D hotspot mutations were identified in 56%, 20%, 43% and 0% of PACs, CASGs, TIFs, and TPPPs, respectively. FISH demonstrated PRKD1/2/3 rearrangements in 13%, 78%, 36%, and 75% of PACs, CASGs, TIFs, and TPPPs, respectively. Histologically, fusion-positive tumors were associated with a high percentage of papillary growth, low percentage of single filing arrangement, a propensity of base of tongue location, and frequent (50%) lymph node metastasis, compared with the mutation-related tumors which had negligible nodal metastasis risk. Our results demonstrated that (1) PACs/CASGs are underpinned by genetic alterations affecting PRKD genes; (2) despite the associations between PAC and PRKD1 hotspot mutations and CASG and PRKD1/2/3 fusion, such distinction is not absolute; and (3) there is of a novel genotypic-phenotypic association whereby fusion-positive tumors are usually located in the base of the tongue, show papillary architecture and have a high risk of nodal metastasis. Genetic analysis of PRKD genes appears to be useful characterizing this spectrum of tumors, not only histologically but also clinically identifying those tumors with high risk of nodal metastasis.

The Role of Molecular Testing in the Differential Diagnosis of Salivary Gland Carcinomas

Salivary gland neoplasms are a morphologically heterogenous group of lesions that are often diagnostically challenging. In recent years, considerable progress in salivary gland taxonomy has been reached by the discovery of tumor type-specific fusion oncogenes generated by chromosome translocations. This review describes the clinicopathologic features of a selected group of salivary gland carcinomas with a focus on their distinctive genomic characteristics. Mammary analog secretory carcinoma is a recently described entity characterized by a t(12;15)(p13;q25) translocation resulting in an ETV6-NTRK3 fusion. Hyalinizing clear cell carcinoma is a low-grade tumor with infrequent nodal and distant metastasis, recently shown to harbor an EWSR1-ATF1 gene fusion. The CRTC1-MAML2 fusion gene resulting from a t(11;19)(q21;p13) translocation, is now known to be a feature of both low-grade and high-grade mucoepidermoid carcinomas associated with improved survival. A t(6;9)(q22-23;p23-34) translocation resulting in a MYB-NFIB gene fusion has been identified in the majority of adenoid cystic carcinomas. Polymorphous (low-grade) adenocarcinoma and cribriform adenocarcinoma of (minor) salivary gland origin are related entities with partly differing clinicopathologic and genomic profiles; they are the subject of an ongoing taxonomic debate. Polymorphous (low-grade) adenocarcinomas are characterized by hot spot point E710D mutations in the PRKD1 gene, whereas cribriform adenocarcinoma of (minor) salivary glands origin are characterized by translocations involving the PRKD1-3 genes. Salivary duct carcinoma (SDC) is a high-grade adenocarcinoma with morphologic and molecular features akin to invasive ductal carcinoma of the breast, including HER2 gene amplification, mutations of TP53, PIK3CA, and HRAS and loss or mutation of PTEN. Notably, a recurrent NCOA4-RET fusion has also been found in SDC. A subset of SDC with apocrine morphology is associated with overexpression of androgen receptors. As these genetic aberrations are recurrent they serve as powerful diagnostic tools in salivary gland tumor diagnosis, and therefore also in refinement of salivary gland cancer classification. Moreover, they are promising as prognostic biomarkers and targets of therapy.

The rare entity of cystadenocarcinoma (CAC) in parotid gland: A single-center experience

PURPOSE

Cystadenocarcinoma (CAC) is an extremely rare disease in parotid gland. This study aimed to identify the clinical characteristics of CAC, and the therapeutic options for its treatment. An attempt was also made to identify postoperative recurrence-related risk factors.

MATERIAL AND METHODS

A retrospective study was conducted of CAC patients treated between 2008 and 2018. Predictive factors for postoperative recurrence (5-year RFS rate) were preliminarily filtered by Kaplan-Meier analysis and then further confirmed by a Cox regression model. Postoperative recurrence was defined as the primary outcome variable and was measured using both univariate and multivariate analysis.

RESULTS

A total of 27 patients were analyzed, and the total incidence of postoperative recurrence was 33.3% (9/27). In the Cox regression analysis, patients who received a superficial parotidectomy were 0.046 times more likely to develop tumor relapse than those who only underwent enucleation (p = 0.032; 95% CI: 0.003-0.070). The chances of tumor recurrence in patients with the cribriform subtype were 9.701 times that for cases with a papillary pattern (p = 0.016; 95% CI: 1.517-62.030). The risk of postoperative recurrence increased abruptly, with an OR of 6.373 (p = 0.042; 95% CI: 1.070-37.965), when LN metastasis was found in patients.

CONCLUSION

Preoperative diagnosis of CAC in parotid gland is extremely important for allowing surgeons to apply appropriate therapeutic strategies (enucleation or superficial parotidectomy). Patients with LN metastasis, cribriform pattern, and Ki-67 positivity should be treated further to avoid tumor relapse.

Historical Evolution of the Polymorphous Adenocarcinoma

The 2017 World Health Organization Classification of Head and Neck Tumors introduced for the first time the diagnostic terminology "cribriform variant of polymorphous adenocarcinoma". This nomenclature attempts to reconciliate the ongoing taxonomical controversy related to cribriform adenocarcinoma of tongue. In order to better understand this classification conundrum, it is imperative for pathologist to comprehend the historical evolution of polymorphous adenocarcinoma formerly known as polymorphous "low grade" adenocarcinoma. This review highlights our understanding of these tumors since their origins.

Polymorphous adenocarcinoma of the salivary glands: reappraisal and update

Although relatively rare, polymorphous adenocarcinoma (PAC) is likely the second most common malignancy of the minor salivary glands (MiSG). The diagnosis is mainly based on an incisional biopsy. The optimal treatment comprises wide surgical excision, often with adjuvant radiotherapy. In general, PAC has a good prognosis. Previously, PAC was referred to as polymorphous low-grade adenocarcinoma (PLGA), but the new WHO classification of salivary gland tumours has also included under the PAC subheading, the so-called cribriform adenocarcinoma of minor salivary glands (CAMSG). This approach raised controversy, predominantly because of possible differences in clinical behaviour. For example, PLGA (PAC, classical variant) only rarely metastasizes, whereas CAMSG  often shows metastases to the neck lymph nodes. Given the controversy, this review reappraises the definition, epidemiology, clinical presentation, diagnostic work-up, genetics, treatment modalities, and prognosis of PAC of the salivary glands with a particular focus on contrasting differences with CAMSG.

Cribriform adenocarcinoma of the minor salivary gland arising in the tonsil with metastasis to a cervical lymph node: A case report with description of fine needle aspiration cytology

Cribriform adenocarcinoma of minor salivary gland (CAMSG) is a rare tumor of the head and neck. We report a case of a 70-year-old female who presented with a 4-5-month history of a left neck mass. CT scan of the neck showed a left neck mass just inferior to the angle of the mandible and left tonsillar prominence. Fine-needle aspiration (FNA) of the neck mass showed epithelial groups with focal cribriform architecture. The cells had round to oval nuclei and fine chromatin. The background contained scattered lymphocytes. A preliminary diagnosis of low grade adenocarcinoma with cribriform features metastatic to a lymph node was made. Subsequent biopsy of the tonsil mass showed a tumor with a combination of tubular, solid, and papillary architecture containing round to ovoid nuclei with very fine chromatin, consistent with cribriform adenocarcinoma of the minor salivary gland. Cribriform adenocarcinoma of minor salivary gland has a documented tendency to metastasize to cervical lymph nodes. Since this neoplasm can cytologically and histologically resemble other neoplasms of the head and neck, including polymorphous low-grade adenocarcinoma (PLGA), papillary thyroid carcinoma (PTC), and occasionally adenoid cystic carcinoma, being aware of and familiar with the cytologic features of CAMSG on FNA smears is important for patient management. Diagn. Cytopathol. 2017;45:468-471. © 2017 Wiley Periodicals, Inc.

Newly described salivary gland tumors

This review concentrates on three salivary gland tumors that have been accepted in the recent literature as new neoplastic entities: mammary analog secretory carcinoma (MASC), sclerosing polycystic adenoma (SPA) and cribriform adenocarcinoma of tongue and other minor salivary glands (CAMSGs). MASC is a distinctive low-grade malignant salivary cancer that harbors a characteristic chromosomal translocation, t(12;15) (p13;q25) resulting in an ETV6-NTRK3 fusion. SPA is a rare lesion often mistaken histologically for low-grade salivary carcinoma. Previously thought to be a reactive fibroinflammatory process, but recent evidence of clonality, recurrences in up 30%, and dysplastic foci suggest it may be truly neoplastic. CAMSG is a distinct tumor entity that differs from polymorphous low-grade adenocarcinoma (PLGA) by location (ie, most often arising on the tongue), by prominent nuclear clearing, alterations of the PRKD gene family and clinical behavior with frequent metastases at the time of presentation of the primary tumor. Early metastatic disease seen in most cases of CAMSG associated with indolent behavior makes it a unique neoplasm among all low-grade salivary gland tumors. Salivary glands may give rise to a wide spectrum of different tumors. They are often diagnostically challenging as morphological features often overlap between different entities. Although conventional morphology in combination with immunohistochemical findings still provide the most important clues for diagnosis, recent advances in molecular pathology offer new diagnostic tools in investigating the differential diagnosis, as well as providing potentially valuable prognostic indicators. In the last two decades, several new salivary gland tumor entities have been described, namely MASC, SPA and CAMSGs.

Cribriform adenocarcinoma of the soft palate with multiple lymph node metastasis and long-term follow-up

INTRODUCTION

Cribriform adenocarcinoma of the tongue and minor salivary glands (CATMSG) is a recently described entity, with most cases previously published as polymorphous low-grade adenocarcinoma (PLGA). Typical cases share some main characteristics, such as oral sites (mainly tongue), regional lymph node metastasis, and morphology resembling solid and follicular variants of papillary thyroid carcinoma.

OBJECTIVE

To present a CATMSG and emphasize the importance of reclassifying PLGAs with unusual behavior.

CASE REPORT

A 78-year-old male presented with an ulcerated mass in the soft palate treated as PLGA. The patient developed 5 regional metastases over 11 years of follow-up, all diagnosed as PLGA. He died due to the disease, and because of the very aggressive behavior of PLGA, all histopathologic slides were revised and the tumor was reclassified as CATMSG.

CONCLUSION

This report emphasizes the importance of reevaluating aggressive PLGA and contributes to a better understanding of CATMSG.

Cribriform adenocarcinoma of the minor salivary glands arising in the epiglottis--a previously undocumented occurrence

A 39-year-old female was referred to her local Ear, Nose, and Throat department with tonsillar hypertrophy. During intubation for a tonsillectomy, a mass was also noted on the epiglottis. Histopathologic examination showed this mass to be a cribriform adenocarcinoma of the minor salivary glands (CAMSG). As far as the authors are aware, a CAMSG has never been documented in the larynx.

Not just another paediatric neck lump: metastatic cribriform adenocarcinoma of the palate in an adolescent

Objective:

This paper reports the case of a 13-year-old girl with a 2-year history of left cervical lymph node swelling that was diagnosed as metastatic cribriform adenocarcinoma of the tongue and minor salivary gland.

Case report:

A 13-year-old girl with a left, level II cervical lymph node underwent excisional biopsy after an ultrasound suggested suspicious features. The histology indicated polymorphous low-grade adenocarcinoma, and a primary lesion in the left palate was identified. The patient underwent left maxillectomy, neck dissection and reconstruction. Histological analysis of resection specimens led to a revised diagnosis of cribriform adenocarcinoma of the tongue and minor salivary gland.

Conclusion:

Cribriform adenocarcinoma of the tongue and minor salivary gland has recently been described as a separate entity to polymorphous low-grade adenocarcinoma in light of histological and behavioural differences, including higher rates of metastasis at presentation. This is the first report in the world literature of an adolescent with this entity. It is possible that some previous reports of polymorphous low-grade adenocarcinoma in childhood would have been more accurately described as cribriform adenocarcinoma of the tongue and minor salivary gland.

Recent advances in the diagnostic pathology of salivary carcinomas

This review concentrates on the most important developments since the WHO classification of 2005. In particular, the identification of specific translocations is revolutionising the way salivary tumours are considered and will have a major impact on future diagnostic practice. This is true so far in four malignancies: mammary analogue secretory, mucoepidermoid, adenoid cystic and hyalinising clear cell carcinomas. In each, the gene rearrangement is found in 80 % or more of cases. Two 2014 publications have added further possible candidates with molecular abnormalities to the list (cribriform adenocarcinoma of the tongue and minor salivary glands and epithelial-myoepithelial carcinoma), but these findings have yet to be confirmed by other investigators. The advances in molecular pathology have also allowed re-evaluation of the morphology; for example, it is now realised that the histological spectrum of hyalinising clear cell carcinoma includes intracellular mucin in over half of cases, as well as tumours with only scanty clear cells. In a separate development, it is now proposed that salivary duct carcinoma can be subdivided along molecular lines, in ways analogous to breast cancer, suggesting new therapeutic prospects in an otherwise highly aggressive malignancy.

Cribriform adenocarcinoma of minor salivary gland: a report of two cases with an emphasis on cytology

Cribriform adenocarcinoma of minor salivary gland (CAMSG) is a recently characterized low grade salivary gland malignancy that most commonly presents as a mass in the base of the tongue, frequently with regional lymph node metastasis. Given its relative rarity and overlapping cytomorphology, CAMSG may be confused with polymorphous low grade adenocarcinoma (PLGA) in minor salivary gland sites and papillary thyroid carcinoma (PTC) in cervical metastasis, in both fine-needle aspiration and excisional specimens. As there are no cytology reports in the literature, we present two new cases of CAMSG and describe the aspiration cytology of the tumor taken from bench top aspirates, compare it with the histomorphology, and discuss the features that may help one avoid misdiagnosis of PTC in the setting of cervical lymph node metastasis. We found that like PTC, aspirates of CAMSG contain polymorphic fragments of epithelial cells arranged in monolayer sheets, papillary fronds and tips, and occasional cribriform configurations, and metachromatic stromal fragments, which may be misinterpreted as colloid. A background of myxoid/mucoid material also reminiscent of colloid was prominent. Differentiation from PLGA is more difficult based strictly on cytology. A review of the most current literature in relation to the molecular and immunohistochemical profiles, therapeutic options, and prognosis is also presented. It is critical for pathologists and clinicians to be aware of this tumor when presented with patients having a cervical lymph node mass in the absence of a primary tumor.

Adenocarcinoma not otherwise specified or cribriform adenocarcinoma on dorsum of tongue?

Market Velker et al.1 recently reported an unusual case of adenocarcinoma arising from the minor salivary gland located on the dorsum of the posterior one third of the tongue in a 66-year-old woman.[...]

[Adenocarcinoma of minor salivary gland origin: a recently described lesion. A case report]

Cribriform adenocarcinoma of salivary gland origin is a rare and recently described lesion. In spite of the high incidence of metastatic spread, the prognosis remains very good. We report a case of a 64-year-old man with cribriform adenocarcinoma of salivary gland origin of the ventral tongue without locoregional or distant metastasis. The patient is currently 43-month post treatment without any local or regional recurrence of the disease. This entity should be kept in mind regarding its good prognosis and its resemblances with papillary carcinoma of the thyroid and adenoid cystic carcinoma with which it should not be confused.

Cribriform adenocarcinoma of the tongue and minor salivary glands: a review

Cribriform adenocarcinoma of the tongue and minor salivary glands (CATMSG) is a tumor occurring mostly, but not exclusively, in the base of the tongue. Other locations are minor salivary glands of the oral cavity. Histopathologically, CATMSG resembles papillary carcinoma of the thyroid gland. It usually reveals a solid growth devoid of colloid, and eosinophilic material present in follicular areas is rather pale in contrast to metastatic foci seen in papillary thyroid carcinoma that shows typical deeply eosinophilic colloid with "moth-eaten peripheries" and cystic configuration. In addition, giant multinucleated cells are not observed in CATMSG and psammoma bodies are found only exceptionally. Unlike papillary thyroid carcinoma, CATMSG is composed of hybrid secretory-myoepithelial cells. Most importantly, CATMSG is consistently negative with both thyroglobulin and TTF-1. CATMSG is a distinct tumor entity that also differs from polymorphous low-grade adenocarcinoma by location, cytology, histological architecture, and behavior, with frequent metastases at the time of presentation. Paradoxically, early metastatic disease seen in most cases of CATMSG is associated with an indolent behavior. It makes CATMSG a unique neoplasm among all low-grade salivary gland tumors.