MASC Gets UNMASKED: Visiting a Rare Tumor with Emphasis on Cytomorphological Features

Abstract

Background:

Secretory carcinoma (SC) is a newly described entity which has been often misdiagnosed earlier as acinic cell carcinoma on cytology. Diagnosing SC was initially based upon identifying the ETV6:NTRK3 fusion gene with the help of fluorescence in situ hybridization (FISH). Lately, with more knowledge of the reliable histomorphology, cytology, and immunohistochemistry features, definitive diagnosis can be confidently made without the help of FISH in almost every case.

Materials and Methods:

Six histologically confirmed cases of SC were studied. The cytology slides of all the six cases were retrieved and reviewed to identify the characteristic features which could have helped in raising the possibility of SC on fine needle aspiration cytology itself. Cell blocks were also studied, wherever available.

Results:

Patients were all male with average age of 35.2 years. The six cases in the current study demonstrated at least focal cytoplasmic vacuolization of varying sizes, papillae formations, and bland nuclear features on fine needle aspirate smears. It was also seen that S-100 and mammaglobin immunohistochemistry (IHC) are very helpful in confirming the diagnosis.

Conclusions:

The results of the current study highlight the cytomorphological features which may help in clinching the diagnosis SC on cytology itself. They also highlight certain cytological features which help to rule out the other differential diagnoses.

INTRODUCTION

Secretory carcinoma (SC) of the salivary glands is a newly described entity, which was often misdiagnosed as acinic cell carcinoma (AciCC) in the past.[1] It has similar morphological, immunohistochemical, and molecular characteristics to its counterpart in breast, mammary SC, and hence was formerly referred as mammary analog SC (MASC). Initially, confirming SC was based upon identifying the ETV6:NTRK3 fusion gene. With more studies adding to our current knowledge of SC, immunohistochemical analysis of tumor cells for S100 and mammaglobin in the proper morphological context can help in making an accurate diagnosis.

Correct preoperative diagnosis of the common salivary gland tumors such as pleomorphic adenoma (PA), Warthin tumor, mucoepidermoid carcinoma (MEC), and AciCC is usually feasible on fine needle aspiration cytology (FNAC) itself, as their cytology features are well known. However, SC of the salivary gland is usually diagnosed postoperatively on histopathology, as data regarding cytomorphology of SC is scarce and cytological features are still unfamiliar to most pathologists. Existing studies have mainly dealt with histomorphology, with very few cytology case series reported worldwide by Forner et al.,[2] Bishop et al.,[3] Griffith et al.,[4] Higuchi et al.,[5] Jung et al.,[6] and Miesbauerová et al.[7] In India, to the best of our knowledge, only two case series have described the cytology of SC, both of which comprised three cases each.[8,9] The remaining were single case reports or dealt with histomorphology. Herein, we report a series of six cases, the largest in India to describe the characteristic cytological features of SC. Being aware of the characteristic cytomorphology of SC will be helpful in differentiating it from its morphological mimics like AciCC and establishing a correct preoperative diagnosis of SC on FNAC itself. We also aim to study the expression of Estrogen receptor (ER), Progesterone receptor (PR), and Human Epidermal growth factor receptor 2 (HER-2) Neu in these tumors since they may serve as potential therapeutic targets and only a few studies have studied them earlier.[10,11]

MATERIALS AND METHODS

This study was an observational, retrospective, descriptive one carried out at a single tertiary care institute in Uttarakhand. The study was approved by the institutional ethics committee and was conducted over a period of 3 years (2018–2020). Six cases diagnosed as SC during the study period were retrieved and reviewed for cytological, histological, and immunohistochemical features. Detailed assessment of the cytology slides was carried out to identify characteristic cytomorphological features, which could contribute to raising the diagnostic possibility of SC in FNAC itself. Both cytology and histopathology slides were reviewed by two experienced cytopathologists (PJ and AK) and histopathologists (AS and PD), respectively, and four junior pathologists (NK, MLA, RJ, VG).

Inclusion criteria for selecting the SC cases were as follows:

1. SC cases with preoperative FNAC were only included

2. Diagnosis of SC confirmed by histopathologic examination

3. Positivity for S-100 and mammaglobin on immunohistochemistry (IHC).

All cases underwent FNAC preoperatively. Blind FNAC from the parotid swelling was performed by a pathologist using a 22-gauge needle, and two passes were attempted for each case. Both air-dried as well as ethanol-fixed cytology smears were prepared. Air-dried FNAC smears were then stained with May Grunwald Giemsa (MGG) stain and ethanol-fixed smears were stained with Papanicolaou stain (PAP) following the standard laboratory protocol.

Milan system for reporting salivary gland cytopathology (MSRSGC) was followed for stratifying the FNAC aspirates into various categories.[12] Hence, the cytology aspirates were placed into one of the following diagnostic categories of MSRSGC:

1. Nondiagnostic

2. Non-neoplastic

3. Atypia of undetermined significance

4. Neoplastic: A) benign

   B) uncertain malignant potential

5. Suspicious for malignancy

6. Malignant.

For two cases, cell blocks were also prepared by conventional plasma-thrombin method and immunocytochemistry was performed. IHC for S-100 (clone: EP32; isotype: rabbit IgG; PathnSitu, Livermore, CA, USA; prediluted) and mammaglobin (clone: EP249; isotype: rabbit IgG; PathnSitu; prediluted) was performed for all cases on the paraffin-embedded tissue blocks at the time of initial histological diagnosis, whereas IHC on cell blocks prepared from cytology aspirates was done at the time of study. The selected cases were further subjected to additional IHC at the time of the study with the following antibodies to study their hormonal profile:

• 1) ER (clone: EP1; isotype: rabbit IgG; PathnSitu; prediluted)

• 2) PR (clone: EP2; isotype: rabbit IgG; PathnSitu; prediluted)

• 3) HER 2 Neu (clone: EP3; isotype: rabbit IgG; PathnSitu; prediluted)

• 4) Ki 67 (clone: MIB-1; isotype: mouse IgG1, kappa; PathnSitu; prediluted)

• 5) CK 5/6 (clone: CK5: EP24; CK6: EP67; isotype: rabbit IgG; PathnSitu; prediluted).

IHC results were interpreted as positive when S-100 showed nuclear and cytoplasmic staining, mammaglobin showed cytoplasmic staining, keratin 5/6 showed membranous staining, and Ki 67 showed nuclear staining. ER and PR nuclear staining and for Her 2 Neu membranous staining were considered positive as per the IHC scoring system followed for breast carcinoma. Clinical details for all cases were noted from case files. Follow-up of five patients was done for a period ranging from 4 to 12 months with a mean follow-up time of 7.2 months. Case 2 was lost to follow-up.

RESULTS

Clinical parameters

The clinical features of the six cases in the current study are summarized in Table 1. The sixth case had a past history of a swelling in the right parotid region 3 years back and was diagnosed as adenocarcinoma, Not otherwise specified (NOS) at that time. Subsequently, he presented with two recurrences and was diagnosed as SC on cytology and histopathology during the first recurrence. During the second recurrence, he also developed bilateral lung metastasis. The patient is alive and is being given chemotherapy.

Table 1.

Clinical and demographic details of the patients

Case No.	Age/sex	Site of tumor	Presenting complaint	Treatment done	Tumor size (largest dimension in cm)	Status during follow-up	Follow-up (months)	Tumor stage, AJCC eighth ed (pTNM)
1.	45/M	Parotid	Swelling ×3 years	Resection and LND	3	AFD	6	pT2N0M0
2.	28/M	Parotid	Swelling ×2 years	Resection and LND	4	AFD	NA	pT2N0M0
3.	37/M	Parotid	Swelling ×1 year	Resection	2	AFD	12	pT1N0M0
4.	45/M	Parotid	Swelling ×1 year	Resection and LND	3	AFD	8	pT2N0M0
5.	20/M	Parotid	Swelling ×3 years	Resection and LND	3	AFD	6	pT2N0M0
6.	36/M	Parotid	Recurrent parotid swelling ×3 years; breathlessness due to bilateral lung metastasis	Resection and LND	4	AWD	4	prT2N0M1

AFD=alive and free of disease, AWD=alive with disease, LND=lymph node dissection, NA=not available, P=pathological, AJCC= American Joint committee on cancer, pTNM=Pathological tumor node metastasis staging for cancer

Cytomorphologic features

A summary of the cytomorphologic features is presented in Table 2. Diagnoses offered for the fine needle aspirates included papillary epithelial neoplasm, AciCC, PA, myoepithelial neoplasm, and MEC. Based on the diagnosis offered on cytology, three cases were categorized as malignant (MSRSGC category 6, malignant), two cases as benign (MSRSGC category 4A, neoplastic: benign), and one case was placed in the category neoplasm, salivary gland neoplasm of uncertain malignant potential (MSRSGC category 4B, neoplastic: Salivary gland neoplasm of uncertain malignant potential [SUMP]).

Table 2.

Cytomorphologic features of SC on FNAC

Features	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6
Cellularity	Cellular	Scanty	Cellular	Cellular	Cellular	Cellular
Cellular arrangement	Cohesive clusters, papillae	Singly scattered cells and few sheets	Sheets, papillae, singly scattered cells, acini	Loosely cohesive sheets, papillae, singly scattered cells, glandular	Loosely cohesive clusters, papillae, singly scattered cells	Loosely cohesive clusters, singly scattered cells, glandular
Binucleated cells	Present	Absent	Present	Absent	Present	Present
Plasmacytoid cells	Present	Present	Present	Present	Present	Absent
Cytoplasmic features	Abundant, granular, varying sized vacuoles	Abundant, granular, occasional vacuoles	Abundant, granular, varying sized vacuoles	Abundant, granular, varying sized vacuoles	Abundant, granular, varying sized vacuoles	Abundant, granular, varying sized vacuoles
Nuclear atypia	Absent	Absent	Absent	Mild	Mild	Absent
Nucleoli	Inconspicuous	Inconspicuous	Inconspicuous	Prominent	Prominent	Prominent
Naked nuclei	Absent	Absent	Occasional	Absent	Present	Absent
Extracellular mucinous material	Present	Absent	Present	Present	Present	Present
Original cytology diagnosis	Papillary epithelial neoplasm favoring AciCC	Possibility of PA	Cellular PA	AciCC	1. AciCC, 2. myoepithelial neoplasm, 3. MEC, 4. cellular PA	1. SC 2. AciCC

AciCC=acinic cell carcinoma, FNAC=fine needle aspiration cytology, MEC=mucoepidermoid carcinoma, PA=pleomorphic adenoma, SC=secretory carcinoma

Possibility of SC on cytology was suggested in one case. In all six cases, FNA cytology had several features in common on smear preparations [Figure 1a–f (Pap-stained cytology smears), Figure 2a–f (MGG-stained cytology smears)]. In all except one, smears were cellular, comprising tumor cells arranged in groups as well as singly scattered in the background. Tumor cells were arranged in varied patterns ranging from sheets to, small, acini-like structures, large arborizing papillae with fibrovascular core and/or tubular–glandular structures. At many places, the tumor cells showed plasmacytoid appearance with eccentrically placed nuclei. Majority of the cells demonstrated uniform, round, bland nuclei or an occasional mild atypia with mild nuclear membrane irregularities and inconspicuous to prominent nucleoli. Binucleation was identified infrequently. Cytoplasm was abundant, eosinophilic and finely granular on MGG stain. All the cases had in common tumor cells containing characteristically vacuolated cytoplasm with multiple small vacuoles. Rarely, signet ring-like tumor cells with a single large vacuole were also noted. In some cases, the large polygonal tumor cells with vacuolated cytoplasm appeared similar to histiocytes present in the background of the cytosmear. Mitotic figures were not identified in any case. Extracellular material was commonly seen and usually comprised of mucin (cases 1, 3, 4, 5, and 6), and in some cases, mucin was abundant. Sections from the cell blocks showed fibrin, red cells, and tumor cells arranged in the form of tubulo-glandular structures lined by tumor cells with moderate amount of granular vacuolated cytoplasm, bland nuclei, and inconspicuous nucleoli [Figure 3a]. Immunocytochemistry on cell blocks revealed the tumor cells to be positive for S-100 and mammaglobin [Figure 3b and c].

Figure 1.

Papanicolaou (PAP) stain. Cellular aspirates show the following: (a) Tumor cells seen lying scattered singly (×200). (b) Large arborizing papillae with transgressing vessels (×200). (c) Tumor cells arranged in sheets, tubuloglandular structures, and binucleated forms (×400). (d) Cells have abundant eosinophilic granular cytoplasm and many show eccentrically located nuclei (×400). (e) Majority of the cells show a uniform, round, bland nuclei. Some cells show a single prominent cytoplasmic vacuole, with the appearance resembling that of a signet ring cell (×400). (f) Extracellular mucinous material present in the background (×200)

Figure 2.

May Grunwald Giemsa (MGG) stain. Cellular aspirates show the following: (a) Tumor cells seen lying scattered singly (×200). (b) Tumor cells arranged in tubuloglandular structures (×400). (c) Cells have abundant cytoplasm and many show eccentrically located nuclei (×400). (d–f) Tumor cells have characteristically vacuolated cytoplasm, with majority of them showing multiple small cytoplasmic vacuoles (d and f, ×400) (e, ×200)

Figure 3.

Cell block. (a) Tumor arranged in the form of tubuloglandular structures lined by tumor cells with moderate amount of granular vacuolated cytoplasm, bland nuclei, and inconspicuous nucleoli (H and E, ×400). (b) Tumor cells showing diffuse S-100 nuclear and cytoplasmic positivity (Immunocytochemistry (ICC), ×400). (c) Tumor cells showing diffuse mammaglobin cytoplasmic positivity (ICC, ×400). H and E = hematoxylin and eosin

Histomorphologic features

Cases 1 through 6 were all diagnosed as SC after surgical resection. On gross examination, the parotid gland showed solitary nodular growth, tan-colored, firm to rubbery consistency, with cyst formation in a few cases. The histomorphology features of SC have been well reported in the past. The histopathology features of our cases have been summarized in Table 3 and Figure 4a–d. Morphological evidence of possible previous FNA was observed in most tumors in the form of stromal fibrosis and/or cholesterol granulomas. IHC staining for S-100 and mammaglobin was strongly and diffusely positive in all cases [Figure 4e and f]. Ki 67 labeling index ranged from 3% to 10%. One of our cases with tumor recurrence and subsequent metastasis to bilateral lungs during the second recurrence suggested an aggressive clinical behavior of the tumor in otherwise low-grade morphology. However, this case did not exhibit facial nerve palsy, significant cellular atypia, necrosis, increased mitosis, or nodal metastasis. This case represents the recurrent and metastatic potential of SC, both of which are a rare presentation for this tumor, despite an apparent low histological grade.

Table 3.

Histomorphologic features of MASC

Features	Case 1	Case 2	Case 3	Case 4	Case 5	Case 6
Pattern	Tubulopapillary	Tubules, papillae with hobnailing, focally as solid sheets	Solid sheet, papillae	Tubulopapillary, focally solid sheet	Tubules, solid sheet	Tubules, microcystic and cribriform pattern
Cytoplasm	Eosinophilic, granular, vacuolated	Eosinophilic, granular, vacuolated	Eosinophilic, granular, vacuolated	Eosinophilic, granular, vacuolated	Eosinophilic, granular, vacuolated	Eosinophilic, granular, vacuolated
Nucleus	Bland, inconspicuous nucleoli	Bland, prominent nucleoli	Bland, inconspicuous nucleoli	Mild atypia, prominent nucleoli	Bland, inconspicuous nucleoli	Bland, inconspicuous nucleoli
Intraluminal/extracellular eosinophilic secretions	Present	Present	Present	Present	Present	Present
Necrosis	Absent	Absent	Absent	Absent	Absent	Absent
S-100 protein	Positive	Positive	Positive	Positive	Positive	Positive
Mammaglobin	Positive	Positive	Positive	Positive	Positive	Positive
Ki 67 (%) IHC	4	3	8	10	5	5
ER IHC	Negative	Negative	Negative	Negative	Negative	Negative
PR IHC	Negative	Negative	Negative	Negative	Negative	Negative
Her 2 neu IHC	Negative	Negative	Negative	Negative	Negative	Negative
Keratin 5/6	Focal positivity	Focal positivity	Focal positivity	Focal positivity	Focal positivity	Focal positivity

IHC=immunohistochemistry, MASC=mammary analog secretory carcinoma

Figure 4.

Representative histomorphology images with various architectural patterns: (a) Tumor arranged in papillary and tubular structures (H and E, ×400). (b) Macrocystic pattern with abundant eosinophilic homogeneous secretions (H and E, ×200). (c) Tumor cells with bland round to oval vesicular nuclei, central conspicuous nucleoli, and abundant granular eosinophilic cytoplasm (H and E, ×400). (d) Microcystic and solid patterns with luminal homogeneous extracellular eosinophilic secretion (H and E, ×200). (e) Tumor cells showing diffuse S-100 nuclear and cytoplasmic positivity (IHC, ×400). (f) Tumor cells showing diffuse mammaglobin cytoplasmic positivity (IHC, ×200). H and E = hematoxylin and eosin, IHC = immunohistochemistry

DISCUSSION

SC is a recently described malignancy which can affect the salivary glands of the head and neck. First described in 2010 by Skálová et al.,[13] it was formerly referred to as MASC. It is characterized by t (12;15) (p13;q25) translocation, which results in the fusion gene ETV6:NTRK3, a characteristic it shares with breast carcinoma of the same name.[13] SC occurs in both children and adults (13–72 years), with slight male predominance.[2] All the patients in the present study were males, with an age range of 20–45 years (mean age 35.2 years). The majority of patients in our series presented clinically with slowly growing, painless parotid gland mass. This is similar to the largest case series on SC by Chiosea et al., in which 94% of patients also presented with a painless parotid mass.[1]

For initial diagnostic evaluation, all of our patients underwent a fine needle aspiration from the parotid gland mass. The cytological features which could help in the diagnosis of this lesion were extensively looked into in the present study with the aim to contribute to a timely diagnosis of SC at the cytology level itself, hence avoiding the diagnostic delay resulting from waiting for histopathologic evaluation of the tumors. In general, the accuracy of FNA for salivary gland tumors is good with certain diagnoses being easy to make (e.g., benign mixed tumor, Warthin tumor, and high-grade malignancies), while other diagnoses are difficult because some salivary gland malignancies (including SC) may show low-grade cytological features or an overlap between benign and malignant features. Also, lack of sufficient studies and literature describing the characteristic cytomorphology of some of these tumors further compounds the difficulty in correctly diagnosing them in fine needle aspirates. The ability to diagnose SC with cytology has been previously described by Griffith et al.[4] In their study, they described tumor cells of SC as arranged in papillary groups on cytology and with abundant multivacuolated cytoplasm. A constellation of characteristic cytological findings were noted in our series that could help in diagnosing SC in FNAC smears. The cytomorphological findings include cellular smears, with tumor cells arranged in varied patterns like thin sheet-like clusters with slight overlapping of cells at places, in an arborizing papillary pattern with transgressing vessels or sometimes as tubules. Cells were dyscohesive and exhibited loose adhesion with indistinct cell borders between the tumor cells. Tumor cells were relatively uniform throughout and exhibited little cellular pleomorphism. The tumor cell nuclei were round and bland and located mostly peripherally, containing small nucleoli. Some binucleated forms were also seen. Cytoplasm was eosinophilic and granular with remarkable cytoplasmic vacuoles, varying from numerous small-sized vacuoles to single large vacuole in a few cells resembling signet ring cells.

Different diagnostic possibilities were suggested on FNAC, of which AciCC was the most common FNA diagnosis as both of them share similar cytological features like single and clustered tumor cells with plasmacytoid appearance, low-grade nuclei and prominent nucleoli, some bare nuclei, and signet ring appearance in a few cells. Both SC and AciCC have similar cellular arrangements in cytology. Cytological distinction between SC and zymogen granule-poor ACiCC is difficult without immunohistochemical or molecular study, since the cytology shows many overlapping features. However, several other features which can favor the diagnosis of SC over AciCC include papillary arrangement of tumor cells, prominent extracellular and intracellular mucinous material, multivacuolated tumor cell cytoplasm with variation in the size of vacuoles, low-grade nuclear atypia, and increased tumor vascularity.[14-16] The oncocytic variant of MEC also sometimes enters the differential diagnosis of SC because of the shared features like abundant eosinophilic cytoplasm and mucin production, making the distinction between these two entities sometimes difficult on FNA. MEC usually does not exhibit prominent papillary appearance, but when present, the papillae are typically lined by mucocytes. In MEC, the vacuoles are univacuolar and cells resemble goblet cells, whereas in MASC, the tumor cells show typically multivacuolated cytoplasm, although sometimes, large single vacuole resembling signet ring cells may be present.[4] Another feature favoring a diagnosis of MEC is presence of squamous differentiation. Another salivary gland tumor which can show some cytomorphological features similar to SC is salivary duct carcinoma (SDCA), as it can also produce mucin and have an eosinophilic vacuolated cytoplasmic appearance. But it is easily distinguished from MASC because of a higher nuclear grade, background necrosis, and a neutrophilic tumor diathesis, which is not observed in SC. Sometimes, SDCA with bland morphologic features does occur leading to a diagnostic challenge. In such cases, the apocrine phenotype of SDCA, which exhibits pleomorphic cells and prominent nucleoli, is still evident and is of great help. Sometimes, particularly in cell blocks, decapitation secretions are identified, thereby supporting SDCA. Apart from malignant salivary gland tumors, SC sometimes also mimics benign salivary gland neoplasms. The latter include oncocytic neoplasms such as oncocytoma, oncocytic cystadenoma, and Warthin tumor. Usually, these benign neoplasms are arranged in more cohesive sheets, lack vacuolated cytoplasm, and show rare mucin production. IHC can help in excluding these oncocytic benign neoplasms, as antimitochondrial antibody is positive and S-100 is negative in theses tumors. As SC displays a prominent cell dyscohesion and vacuolated cytoplasm,[4] two of the previously reported cases of SC gave the initial impression through cytology of a PA. Sometimes, the dyscohesive tumor cells of SC enmeshed in mucin can mimic the myxoid stroma of PA. In such circumstances, a careful examination of the cellular elements would help to exclude the possibility of PA if the cytological and architectural features of SC discussed above are noted. Skálová et al.[17] recently showed that SC can transform into a high-grade tumor. Therefore, it should be considered by cytologists that tumor cells with high-grade nuclear atypia might also appear in the cytological specimen of SC. Immunohistochemical staining patterns consistent with SC include strong S-100 positivity, as well as positivity for keratin 7, vimentin, mammaglobin, and GATA3.[2,18] Ancillary tests such as PAS-D–positive cytoplasmic granules, strong DOG-1, weak S-100 expression, and negative mammaglobin staining support AciCC; p63 positivity, MAML2 translocation, and S-100 negativity support MEC; and AR positivity coupled with S-100 negativity supports Salivary duct carcinoma (SADC).[4,19] In all our cases, the IHC results and morphological features were consistent with the diagnosis of SC. IHC testing was done for all cases and was immunopositive for S-100 and mammaglobin. Regarding the immunoexpression of ER, PR, and Her 2 Neu, our study showed similar results to other studies, with all cases being triple negative.[11,13] Assessment of Her2/neu status may be considered imperative, as it can be explored as a potential therapeutic option. Hormonal profile of MASC is still a matter of debate as literature on this aspect is scanty.[20] Focal positivity of keratin 5/6 along with negativity for hormone receptors and Her2/neu points to a more basal-like phenotype, which usually has a bad prognosis. However, SC, in sharp contrast to other basal-like carcinomas, usually shows an excellent prognosis, in spite of nodal metastasis, pointing to the heterogeneity of basal-like tumors.[21]

At the molecular level, there are certain salivary gland tumors with characteristic translocations in which proving the presence of a translocation is not stringently required for the diagnosis (e.g., adenoid cystic carcinoma) because of the well-established morphological findings. Characteristic translocation seen in SC is a fusion gene ETV6:NTRK3; becoming more familiar with its typical morphology and IHC may be helpful in reducing the need of molecular test for diagnosis.

Initial ancillary studies helping to make a precise classification include a simple histochemical stain such as periodic acid-Schiff after diastase (PASD) and/or mucicarmine, either on a smear or cell block. Immunohistochemical markers can be assayed on the cell block or scrape material of a slide, which help further to lessen the diagnostic dilemma. It confirms the malignancy, and thus allows the surgeon to consider a need for neck dissection upfront because SC has been shown to have a slightly higher frequency for lymph node metastases compared to its closest mimic AciCC.[1] If well aware of the cytomorphological features of SC, even pathologists working in resource-poor settings with unavailability of cell blocks and/or immunocytochemistry should also be able to suggest the diagnostic possibility of SC on FNAC smears.

CONCLUSION

A diagnosis of MASC can be rendered confidently on an FNAC with IHC supporting it on a cell block itself. Since preoperative FNA is increasingly and widely used for tumors of the salivary gland owing to its simplicity and safety, it is necessary for cytologists and pathologists to be aware of the cytology of recently established tumors such as SC. This can particularly be beneficial in resource-poor settings where access to cell blocks, immunocytochemistry, and molecular tests is difficult.

Ethical approval

Ethical clearance from institutional ethical committee was obtained.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.