IntroductionBasal cell adenomas (BCAs) are rare occurrences

and most of them usually arise from the parotid glands (80%)[1]. Other sites, such as the lips, palate and na-sal septum have also been encountered. This condition usually affects people in the fifth decade of life, with a higher prevalence in women than men. Histologically, a basaloid cell layer surrounded by hyaline substance is noted. The differentiating factor for this tumor, when compared to other benign mixed tumors and salivary gland neoplasms is the absence of myoepithelial cells. A  strong suspicion of other diagnoses, such as pleo-

morphic adenoma and malignant adenoid cystic car-cinoma, should be present as these tumors often have histological similarities, especially if relying on cytol-ogy alone. Here, we present a case of one such diagnos-tic uncertainty in a 55-year-old woman who presented with an oral tumor, which was found to be a BCA, most likely.

Case ReportA 55-year-old woman non-smoker, presented to

the surgical department with 2 years history of a pain-less swelling in the floor of the mouth. The swelling was slowly growing in size. She reported no associated

Basal cell adenoma of the salivary gland: Cribriform type, a rare case with review of literature

Raghunath Prabhu1, Neha Kumar2, Sakshi Sadhu1, Rajgopal Shenoy1, Kuladeepa Ananda Vaidya3

Case Report

Arch Clin Exp Surg 2016;5:246-249doi:10.5455/aces.20140304011652

ABSTRACT

Basal cell adenoma (BCA) of the salivary glands is a rare benign tumor resembling pleomorphic adenoma, but with a prominent basaloid cell layer. The majority of these tumors arise in the parotid glands and account for only 1% of all salivary gland epithelial tumors. We report one such case of a swelling in the floor of the mouth in a 55-year-old female where BCA is the most likely diagnosis; however, histological variation does show a similarity to malignant adenoid cystic carcinoma, thereby making the diagnosis difficult. The incidence of malignancy is relatively higher in the submandibular, sublingual and minor salivary glands. Approximately, 85% of sublingual gland tumors are malignant. Thus, we should be more careful when making a diagnosis in minor salivary gland tumors.

Key words: Adenoid cystic carcinoma, adenoma, basal cell, clinicopathological feature, cribriform, excision, immunohisto-chemistry, minor salivary gland, oral cavity

1Department of Surgery, Kasturba Medical College, Manipal University, Manipal, Karnataka, India, 2Foundation Year 1, University Hospital of North Staffordshire NHS Trust, London, United Kingdom, 3Department of Pathology, Srinivasa Institute of Medical Sciences and Research Centre, Mukka, Mangalore, Karnataka, IndiaRaghunath Prabhu, MD, Department of Surgery, Kasturba Medical College, Manipal University, Manipal, Karnataka, India.e-mail: drraghu81@yahoo.co.inJanuary 14, 2014 / March 04, 2014

Author affiliations :

Correspondence :

Received / Accepted :

1Bauru Dental SchoolUniversity of São PauloBauru–SP, Brazil

2Araraquara Dental SchoolSão Paulo State UniversityAraraquara-SP, Brazil

Received: February 05, 2012 Accepted: February 29, 2012 Arch Clin Exp Surg 2012;X: X-XDOI: 10.5455/aces.20120229052919

Corresponding authorÉrica Dorigatti de AvilaDepartamento de Estomatologia da Faculdade de Odontologia de BauruUniversidade de São Paulo (USP)Avenida Alameda Octávio Pinheiro Brizola, 9-75, 17012-901 Bauru–SP, Brasilerica.fobusp@yahoo.com.br

Original Article

Increased of Langerhans Cells in Smokeless Tobacco-Associated Oral Mucosal Lesions

Érica Dorigatti de Ávila1, Rafael Scaf de Molon2, Melaine de Almeida Lawall1, Renata Bianco Consolaro1, Alberto Consolaro1

Abstract

Objective: To evaluate the changes in the number of Langerhans Cells (LC) observed in the epithelium of smokeless tobacco (SLT-induced) lesions. Methods: Microscopic sections from biopsies carried out in the buccal mucosa of twenty patients, who were chronic users of smokeless tobacco (SLT), were utilized. For the control group, twenty non-SLT users of SLT with normal mucosa were selected. The sections were studied with routine coloring and were immunostained for S-100, CD1a, Ki-67 and p63. These data were statistically analyzed by the Student’s t-test to investigate the differences in the expression of immune markers in normal mucosa and in SLT-induced leukoplakia lesions. Results: There was a significant difference in the immunolabeling of all markers between normal mucosa and SLT-induced lesions (p<0.001). The leukoplakia lesions in chronic SLT users demonstrated a significant increase in the number of Langerhans cells and in the absence of epithelial dysplasia. Conclusion: The increase in the number of these cells represents the initial stage of leukoplakia. Key words: Smokeless tobacco, leukoplakic lesions, cancer, langerhans cells, chewing tobacco.

IntroductionAmong tobacco users, there is a false be-

lief that SLT is safe because it is not burned, which leads many people to quit cigarettes and start using SLT [1]. However, SLT con-tains higher concentrations of nicotine than cigarettes and, in addition, nearly 30 carci-nogenic substances, such as tobacco-specific N-nitrosamines (TSNA), which is formed during the aging process of the tobacco, [2-4] and which presents high carcinogenic poten-tial. Moreover, because the tobacco has direct

contact with the oral mucosa and creates a more alkaline environment, its products may even be more aggressive to tissue [5]. The percentage of SLT users is lower compared to cigarette users; however, usage is increasing among young individuals and it is therefore a significant and disturbing danger [6,7].

Initial studies on the effects of SLT on the oral mucosa demonstrated the formation of white lesions induced by chronic exposure to tobacco, characterized by epithelial thicken-ing, increased vascularization, collagen altera-

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features such as xerostomia, sialorrhea, or pain. There was no difficulty in the movement of the tongue. Her general well-being was otherwise unremarkable, and oral hygiene was good. Her background included hy-pertension and type 2 diabetes mellitus, as well as clini-cal depression.

On examination, all her vitals were stable. An oval

of the mouth on the right side, not crossing the mid-line (Figure 1). The mucosa over the swelling appeared normal, and the trans-illumination test was negative. There was no tenderness over the swelling and no local rise of temperature. It was firm to hard in consistency and was non-fluctuant, but was mobile in all directions. No local lymph nodes were palpable.

Her blood results were all within normal limits (full blood count, urea, and electrolytes). Subsequently, she underwent an ultrasound scan of the neck, which showed a well-defined hypoechoic lobulated lesion with smooth margins in the right submandibular re-gion deep to the muscles. Magnetic resonance imaging of the head and neck showed a well-defined, lobulated heterogeneously enhancing T1 iso-hypointense and

3.2 cm in the right sublingual space (Figure 2). Non-enhancing necrotic areas were seen within the tumor.

Figure 1. An oval swelling measuring 4 cm × 3 cm was seen on the floor of the mouth on the right side, not crossing the midline.

Figure 2. Magnetic resonance imaging of the head and neck showed a well-defined, lobulated heterogeneously enhancing T1 iso-hypointense and T2 hyperintense lesion measuring 3.5 cm × 2.9 cm × 3.2 cm in the right sublingual space.

Figure 3. Wide local excision of the tumor with 0.5 cm margin.

Figure 4. Histopathology revealed an encapsulated tumor composed of small basaloid cells arranged in tubules and a cribriform pattern.

There was no evidence of infiltration of the adjacent muscles or median raphe. No hemorrhage or calcifica-tion was observed within the lesion. The right subman-dibular gland was normal in size and signal intensity. A  few sub-centimeter lymph nodes were seen in the level 1 B region.

An excision biopsy of this lesion was planned. In-tra-operatively there was no infiltration of the tumor to the surrounding muscles and a wide local excision with 0.5 cm margin was performed (Figure 3). She was then discharged post an uneventful recovery and is on regu-lar follow-up.

The histopathology (HPE) reported an encapsulat-ed tumor composed of small basaloid cells arranged in

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248 Basal cell adenoma of the salivary gland

Archives of Clinical and Experimental Surgerywww.acesjournal.org

tubules and a cribriform pattern. The cells were found to have basophilic nuclei and scant cytoplasm, con-taining densely eosinophilic basement membrane like material within the tubules. These were surrounded by hyalonized stroma with thin walled blood vessels and occasional lymphoplasmacytic infiltrate. No perineu-ral invasion was seen (Figure 4). The conclusion from that report was of a high likelihood of the lesion being a BCA of the salivary gland. The absence of perineu-ral invasion and good circumscription with a capsule ruled out adenoid cystic carcinoma in this case. How-ever, immunohistochemistry (IHC) staining with C-kit favored a diagnosis of adenoid cystic carcinoma. In view of this, a regular follow-up of the patient was suggested.

DiscussionSalivary gland tumors account for <3% of all the

neoplasms [2]. Approximately, 80% of these are of epi-thelial origin, and the majority of these being benign adenomas. As mentioned before, BCAs constitute about 1% of the salivary gland tumours. Kleinsasser and Klein first described monomorphic adenomas in 1967 and BCAs are a subtype of this entity, as classified by the World Health Organization [3].

BCA are benign and made up of basaloid cells with a definite basement membrane like structure and lacking a myoepithelial component, unlike pleomor-phic adenomas [4]. Just-like in our patient, BCAs are characterized by their slowing growing nature and are generally asymptomatic. Our patient also fits into the average age range for developing this lesion, which is thought to be around 57 years [5]. BCA also tend to form cysts, although this was not observed in our case.

Histologically, there are several similarities between BCA and pleomorphic adenomas; however, the distin-guishing feature of BCA is the absence of chondroid tissue and myxoid stroma [6]. Instead, BCA have nu-merous endothelial blood vessels with prominent small vessels; hence, they appear hemorrhagic on Computed tomography [7]. Adding weight to this diagnosis is the fact that pleomorphic adenomas tend to affect younger people more often than older patients, such as ours.

Another factor contributing to the diagnostic di-lemma in such types of intraoral tumors is the near sim-ilarity between the benign and malignant neoplasm.

The common minor salivary gland tumors such as the pleomorphic adenoma, BCA, adenoid cystic carcino-ma, and low grade adenocarcinoma present with simi-lar morphological and immunohistochemical features to a large extent, thereby making a preoperative diagno-sis difficult. An excision biopsy would be ideal to clinch the diagnosis [8]. The presence of the cribriform pat-tern in this case makes it a rare case and relatively dif-ficult to distinguish from the adenoid cystic carcinoma. The cribriform type has a higher female predilection, affect the elderly, tend to be well-circumscribed and do not recur after a local excision [9]. IHC plays a key role in differentiating these types of tumors from the ade-noid cystic carcinoma. These types of tumors are nega-tive for MMP9, laminin, CD117, and myoepithelial marker (SMA, S100 and calponin) in the cells around the cribriform spaces [9]. If this is indeed the case, the patient will have a very good prognosis, as these tumors are benign and without any infiltrative features.

ConclusionBCAs are rare benign neoplasms of the salivary

gland and share a close resemblance to malignant ad-enoid cystic carcinoma, especially the cribriform type. A  clear HPE report, along with immunohistochemis-try is needed to distinguish between these two enti-ties. Our case highlights the diagnostic challenge en-countered when faced with such a lesion and clinicians should explore both possibilities prior to making final management decisions.

Conflict of interest statementThe authors have no conflicts of interest to declare.References

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