Case Reports in Pathology

Volume 2014 (2014), Article ID 982432, 4 pages

http://dx.doi.org/10.1155/2014/982432

Case Report

Sclerosing Polycystic Adenosis of the Retromolar Pad Area: A Case Report

Sepideh Mokhtari,¹ Saede Atarbashi Moghadam,¹ and Abbas Mirafsharieh²

¹Department of Oral and Maxillofacial Pathology, Dental School of Shahid Beheshti University of Medical Sciences, Tehran 19857-17443, Iran

²Modarres Hospital, Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran 19857-17443, Iran

Received 20 September 2013; Accepted 11 October 2013; Published 3 March 2014

Academic Editors: E. Miele and P. Tosi

Copyright © 2014 Sepideh Mokhtari et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract.

Sclerosing polycystic adenosis is a rare pathological lesion that affects salivary glands. The majority of cases involve the parotid and its occurrence in minor glands is exceedingly rare. Here, we report the first case of this lesion in the retromolar pad area and discuss its histological features and immunohistochemical reactivity with αSMA and Ki67 markers. A review of the literature on its immunohistochemical profile is also provided. Sclerosing polycystic adenosis has a diverse histomorphology and should be differentiated from other more important pathologic lesions.

1. Introduction

To the best of our knowledge, 54 cases of sclerosing polycystic adenosis (SPA) of salivary glands have been reported. SPA characteristically arises in the major glands, and the majority of cases involve the parotid [1]. Some cases have also been reported in minor salivary glands of mucobuccal fold, hard palate, floor of mouth, and buccal mucosa [2, 3]. SPA has been reported in a wide age range from childhood to the eighth decade of life [1]. Here, we report the first case of SPA in the retromolar pad area.

2. Case Report

A 60-year-old male presented with swelling in his retromolar pad area with two months’ duration. There was no tenderness or ulceration. Excisional biopsy of the lesion was performed and a well-circumscribed soft tissue lesion was excised. Histopathologic examination showed lobules of hyalinized connective tissue with epithelial components of ductal and acinar differentiation. Ductal structures formed variably sized cysts or they were packed as small ducts similar to the sclerosing adenosis of the breast. Ducts were lined by flattened to cuboidal epithelial cells and some cells had apocrine metaplasia. Mucous cells were frequently seen (Figures 1, 2, and 3). Periductal fibrosis with lamellar architecture was a common feature. Occasional hyaline globules were also present. Epithelial hyperplasia of ductal structures, formed solid nests, cribriform structures and intraductal anastomosing bridges. Few chronic inflammatory cells were infiltrated throughout the lesion.

Figure 1: Large cystic spaces and cribriform structures were present throughout the lesion (×100).

Figure 2: Apocrine metaplasia was evident throughout the lesion (×400).

Figure 3: Mucous cells were frequently seen (×400).

Immunohistochemical staining for αSMA and Ki-67 was performed. Myoepithelial cells, surrounding ductal elements, demonstrated immunoreactivity for αSMA (Figure 4). Immunohistochemical examination with Ki-67 revealed less than 1% positivity in lesional cells (Figure 5). The proliferative cells were present within ductal elements of cribriform structures, which explained transluminal duct hyperplasia.

Figure 4: Immunohistochemical examination with αSMA confirmed the presence of a peripheral myoepithelial layer around all ductal structures (×400).

Figure 5: Less than 1% of lesional cells were immunoreactive for Ki-67 antibody (×400).

3. Discussion

There is a controversy whether SPA is a neoplasm or reactive lesion. Clonal nature of cells has been demonstrated in some cases [4]. Some viruses such as human papilloma virus (HPV) and Epstein-Barr virus (EBV) may also have a role in pathogenesis of salivary gland diseases. One recent study has demonstrated EBV expression in tumor cells supporting the neoplastic nature of SPA and a possible association with Epstein-Barr virus. Interestingly, no immunoreactivity has been observed for HPV [5].

Reports of cytological atypia or dysplasia within some SPA have added to controversies about the nature of this lesion. Atypia may be found within the ductal epithelial cells ranging from mild to severe dysplasia and carcinoma in situ. However, the lobular architecture is always maintained and invasive carcinoma has not been identified in SPA cases [6].

SPA has diverse histological features. This lesion has a strong resemblance to the fibrocystic disease of breast [2]. Sclerosis and marked adenosis of ductal elements were evident in this case, but adenosis of acini was lacking. Sebaceous, squamous, foamy, and vacuolated cells as well as acinar cells with cytoplasmic zymogen granules have been described in this lesion [2]. However, our case was devoid of these features. Gnepp et al. have also reported two cases with lipomatous stroma [7].

Some authors have investigated immunohistochemical staining profile of cells in SPA. A review of previous studies is presented in Table 1. However, more investigations are required to establish the immunohistochemical profile of this lesion.

Table 1: A review of immunohistochemical investigations in SPA cases.

Investigators
Markers
Immunohistochemical reactivity

Fulciniti et al. (2010) [9]
Collagen IV
Enhanced lobular architecture

Cytokeratin 14
Enhanced the ratio of apocrine cells present in the epithelial lining of lobular structures

Gross cystic disease fluid protein (GCFDP)
Sebaceous cells

Gurgel et al. (2010) [8]
Ki-67
Positive in less than 1% of cells

CKAE1/AE3, EMA, GCDFP-15
Tubuloacinar elements

Estrogen, progesterone, and CK 34βE12
Negative

SMA, S100
Myoepithelial layer

Swelam (2010) [5]
S100
Lesional ductal and spindle-shaped cells

Bcl-2
Strong, diffuse cytoplasmic immunoreactivity in basal cells of neoplastic cells

Ki-67
Sporadic positivity in Basal cells of neoplastic ductal epithelium

EBV
Expression in neoplastic S100 positive cells

HPV-1
Negative

Meer and Altini (2008) [2]
P63
Peripheral layer of cells surrounding acini, ducts, and cystic spaces outlining these structures

AE1/AE3
In ductal lining cells of tubuloacinar elements

S100
Ductal cells and spindled myoepithelial cells

AE1/AE3, CAM5.2, EMA, antimicrobial antibody, BRST-2, S100
Luminal cells

Bharadwaj et al. (2007) [10]
Cytokeratin
In ductal and acinar elements

SMA, S100
Myoepithelial layer

Skálová et al. (2006) [4]
CKAE1/AE3
Positive in ductal and acinar cells

EMA, S100, antimitochondrial antibody
Variably positive

CEA, p53, and HER-2/neu
Negative

GCDFP-15
Acinar cells with coarse eosinophilic cytoplasm

Progesterone receptors
Positive in 15% to 20% of epithelial cells

Estrogen receptors
At least focally in 5% of ductal cells in dysplastic and hyperplastic foci

SMA, P63, and calponin
Myoepithelial layer

Gnepp et al. (2006) [7]
Calponin, SMA, muscle specific actin, S100
Myoepithelial layer

SPA is treated with conservative surgical excision with tumor-free margins and recurrence is rarely encountered [8].

Conflict of Interests

The authors declare that there is no conflict of interests regarding the publication of this paper.

References

C. A. Eliot, A. B. Smith, and R. D. Foss, “Sclerosing polycystic adenosis,” Head and Neck Pathology, vol. 6, no. 2, pp. 247–249, 2012.

S. Meer and M. Altini, “Sclerosing polycystic adenosis of the buccal mucosa,” Head and Neck Pathology, vol. 2, no. 1, pp. 31–35, 2008.

V. L. Noonan, J. R. Kalmar, C. M. Allen, G. T. Gallagher, and S. Kabani, “Sclerosing polycystic adenosis of minor salivary glands: report of three cases and review of the literature,” Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology and Endodontology, vol. 104, no. 4, pp. 516–520, 2007.

A. Skálová, D. R. Gnepp, R. H. W. Simpson et al., “Clonal nature of sclerosing polycystic adenosis of salivary glands demonstrated by using the polymorphism of the human androgen receptor (HUMARA) locus as a marker,” American Journal of Surgical Pathology, vol. 30, no. 8, pp. 939–944, 2006.

W. M. Swelam, “The pathogenic role of Epstein-Barr virus (EBV) in sclerosing polycystic adenosis,” Pathology Research and Practice, vol. 206, no. 8, pp. 565–571, 2010.

G. L. Ellis, “What's new in the AFIP fascicle on salivary gland tumors: a few highlights from the 4th series atlas,” Head and Neck Pathology, vol. 3, no. 3, pp. 225–230, 2009.

D. R. Gnepp, L. J. Wang, M. Brandwein-Gensler, P. Slootweg, M. Gill, and J. Hille, “Sclerosing polycystic adenosis of the salivary gland: a report of 16 cases,” American Journal of Surgical Pathology, vol. 30, no. 2, pp. 154–164, 2006.

C. A. S. Gurgel, V. S. Freitas, E. A. G. Ramos, and J. Nunes Dos Santos, “Sclerosing polycystic adenosis of the minor salivary gland: case report,” Brazilian Journal of Otorhinolaryngology, vol. 76, no. 2, p. 272, 2010.

F. Fulciniti, N. S. Losito, F. Ionna et al., “Sclerosing polycystic adenosis of the parotid gland: report of one case diagnosed by fine-needle cytology with in situ malignant transformation,” Diagnostic Cytopathology, vol. 38, no. 5, pp. 368–373, 2010.

G. Bharadwaj, I. Nawroz, and B. O'Regan, “Sclerosing polycystic adenosis of the parotid gland,” British Journal of Oral and Maxillofacial Surgery, vol. 45, no. 1, pp. 74–76, 2007.