A Giant Submandibular Sialolith in the Setting of Chronic Sialodenitis: A Case Report and Literature Review

Sialolithiasis affects about 1% of the population and represents over 50% of disease that are associated with major salivary glands. Although the etiologies of sialolithiasis have been heavily debated, most agree that there is a multifactorial causation. Most authors conclude that salivary stones are formed from the deposition of calcium salts within the ductal system of salivary glands usually originating from desquamated epithelial cells, foreign bodies, microorganisms, and/or mucous plugs. Sialolith size varies from 6mm to 8cm. Those larger than 1.5cm have been deemed “giant sialoliths”, or megaliths. There are only 13 reported cases of sialoliths greater than 55mm. These appear to occur largely in the submandibular glands, and have a male predilection. We report a case of a giant sialolith in a 48-year-old AfricanAmerican male presenting with a chronic sialadenitis, followed by a literature review of giant sialolith pathology and options for treatment. ABBREVIATIONS cm: Centimeters; mm: Millimeters; CT: Computed Tomography INTRODUCTION Sialolithiasis is considered to be the most common nonneoplastic salivary disorder and represents about 50% of all major salivary gland disease [1]. This benign disorder has a relatively low prevalence at roughly 1% of the population with symptomatic sialolithiasis occurring at a rate of 0.45% [1-3]. The etiology of the sialolith is both controversial and multifactorial with some suggesting that sialolith formation is precipitated/ exacerbated by the presence of desquamated epithelial cells, foreign bodies, microorganisms, and/ or mucous plugs within the ductal canal, potentially creating a nidus for calcium deposition, as well as other etiologic agents [1]. For example, stasis of saliva due to the course of the ductal system or the nidus itself, can enhance the development of a salivary stone [2]. Other precipitating factors that predispose sialolithiasis are metabolic; i.e. Gout [1]. We present a case report that describes a giant sialolith in the left submandibular region with perforation of floor of oral cavity, as well as discernable facial asymmetry. Clinical presentation, radiographic, and histologic features are discussed, as well as management options followed by a review of the literature. CASE PRESENTATION HPI/Clinical Presentation A 48-year-old African American male presented to the oral and maxillofacial surgery clinic at Meharry Medical College, Nashville, TN with a complaint of facial pain and swelling associated with the left submandibular region. The patient reported three months of progressive swelling, and recent persistent pain during mealtime. The patient recorded a 10-pound weight loss, however denied nausea, vomiting, fever, chills, paresthesias and dyspnea. Past medical and surgical histories included obesity and left foot 5th digit osteomyelitis secondary to nail injury treated by incision and drainage and followed by amputation of left foot digit. The patient denied any allergies. Social history included smoking one pack of cigarettes every other day for over 20 years and drinking beer or wine weekly. Family history was noncontributory. Head and neck examination revealed moderate asymmetry of the left neck predominately in the submandibular region (Figure 1A). The area was solid and tender to palpation. No extra-oral erythema or purulence was noted. In addition, there was no associated lymphadenopathy or temporomandibular associated Central Gill et al. (2016) Email: Ann Otolaryngol Rhinol 3(8): 1128 (2016) 2/7 pathologies. Maximum incisal opening was approximately 30mm, with guarding due to pain. Intraoral exam revealed an oropharynx that was clear, a uvula that was midline with no associated palatal draping. The left posterior floor of the mouth exhibited a perforation of approximately 2cm as well as a large, plaque-covered, movable calculus (Figure 1B). In addition, the entire left floor of mouth was mildly elevated, indurated and tender to palpation. Panoramic imaging revealed a large, oblong radiopaque mass superimposed on the left mandibular angle (Figure 2). Computed tomography (CT) scan of the region showed a heterogeneous enhancement and mild generalized enlargement of the left submandibular gland. Centered within the posterior aspect of the gland, and extending to the floor of the mouth along the course of Wharton’s duct, there appeared to be a densely calcified stone measuring 2.1 x 4.3 x 3.1 cm (Figures 3A,3B). Differential Diagnosis A working differential diagnosis was developed based on the patient’s medical history, symptomatology, clinical presentation, and radiographic findings. The following were suggested as possible differential diagnoses: Sialolithiasis with a concomitant left submandibular chronic sialadenitis, foreign body, calcified lymph node, vascular calcification, osteomas, myositis ossificans, and/or a calcified neoplasm [4]. Sialolithiasis was deemed to be the most definitive diagnosis based upon the work-up presented. Hospital Course The patient was consented and taken to the operating room with a diagnosis of chronic sialolithiasis/chronic sialadenitis of the left submandibular gland. The treatment plan was to explore the ductal pathway along the left floor of the mouth, as well as a left submandibular gland sialadenectomy, and left sialolithectomy. The gland was accessed via a modified Risdon approach and found to be fibrotic upon evaluation. Further dissection along Wharton’s duct revealed a grossly dilated duct. The distal portion of the duct was then ligated and the gland was then removed. With further manipulation the proximal duct, there was no success with retrieving the sialolith and it was subsequently dislodged through the floor of the mouth into the oral cavity, via a tear in Wharton’s duct leaving a large perforation through the floor of the mouth. The proximal duct was then ligated. The perforation was closed intraorally with 3-0 resorbable, synthetic suture. The submandibular gland, attached duct, and sialolith were sent for final gross pathologic/histological evaluation. Histology of specimen A gross examination of the specimen identified a giant sialolith that measured, 5.7cm x 2.3cm x 2.2cm and the left submandibular gland specimen (Figure 4). The submandibular gland presented as a rubbery tan nodule weighing 20 grams, measuring 4.5cm x 3.0cm x 2.3cm. Histological examination of the submandibular gland showed lobules separated by dense fibrous connective tissue. The lobules contained glands composed of both serous and mucus cells and small ductiles. A dense chronic inflammatory infiltrate extended to the lobules and also in the surrounding dense fibrotic stroma (Figures 5A, 5B, 5C). No neoplastic or Figure 1 Preoperative extraoral and intraoral photographs. (A) – Moderate left-sided lower facial swelling present (B) Calculus perforated through floor of mouth. Limited opening. Figure 2 Panoramic View: Large radiopaque mass superimposed on left posterior mandible. Figure 3 CT Maxillofacial w/ Contrast (A) – Coronal View: Large oblong radiopaque mass associated with left submandibular gland. Gland is markedly enlarged. Left facial asymmetry appreciated. (B) Sagittal View: Large radiopaque mass roughly 3cm in height. dysplastic changes were identified during examination. The above findings characterized a definitive diagnosis of a giant sialolith arising from an associated chronic sialadenitis of the left submandibular gland. The patient returned to our clinic at 2 weeks for a surgical follow-up. Healing was uneventful and the patient was satisfied with treatment. DISCUSSION Sialolithiasis affects about 1% of the population and represents over 50% of diseases that are associated with the major salivary glands [1]. The average age at diagnosis is 3070 years [5]. Although all major and minor salivary glands can Central Gill et al. (2016) Email: Ann Otolaryngol Rhinol 3(8): 1128 (2016) 3/7 be involved, the submandibular gland is involved in 80-90% of cases [4, 6]. Symptoms can be diverse, depending on the gland involved and the location and size of the sialolith and tend to become exacerbated at mealtime [7]. Some patients may deny any associated symptomatology at presentation [8]. Swelling has been reported in over 94% of cases; pain in 65.2%; purulence in 15.5% of cases [1]. Although a good physical exam can predictably give practitioners a definitive diagnosis, the role of imaging with diagnosing sialolithiasis is also important to consider. Plain film is a valid method of obtaining information; however it may not be the most predictable imaging modality in the diagnosis of sialolithiasis. Due to the various compositions, stones can be radiopaque or radiolucent. It is estimated that 80% of submandibular stones are radiopaque, while parotid and sublingual stones are 40% and 20% respectively [1]. Computed Tomography (CT) and/ or MRI might be indicated when high suspicion of sialolithiasis is present, but no pathology is noted on plain films. Not only can these images help rule out other disorders, glandular involvement can also be accessed [1]. Several theories have been described as to why there is a predilection for the submandibular gland. One reason may be the inferior positioning to Wharton’s duct making the flow of saliva against the force of gravity [1]. In addition, the tortuous path of Wharton’s duct, with its two acute bends, may predispose the submandibular ductal system to the development of sialolithiasis [1,7]. The length of Wharton’s duct increases the transit time of saliva and is the most significant factor in the formation of salivary stones [1]. This anatomy also lends to the increased viscosity of the saliva and relatively high content of calcium salts, specifically phosphates, carbonates, and oxalates which make the submandibular gland more prone to stone formation. Most of the giant sialoliths reported in the article were associated with the submandibular gland and were within the ductal system, with only 26% found in the gland parenchyma [2, 9, 10]. Sialoliths are thought to enlarge at the rate of approximately 1–1.5 mm per year, although some reports show a rate of 3.5mm per year [11]. Stones larger than 3 cm are extremely rare (Table 1). Mean size is roughly 7.3mm, but stones greater than 8cm have been documented [6, 66]. There are only 13 cases of sialoliths greater than 55mm. The largest giant sialolith reported was 83mm in length and located within the submandibular duct [66]. Perforation through the duct and floor of the mouth by a large stone is rare, but has also been reported and is also one of the key features of this clinical presentation [44, 60, 71, 72]. Epidemiologic studies suggest that the vast majority of giant sialoliths have a male predilection, with women only representing 9.7% in this review sample size. The youngest patient in this sample is 10 and oldest is 75 years of age [71, 72]. Figure 6 depicts an algorithm for the management of patients that present with sialolithiasis. Treatment options are based upon size, location, sialolith number and associated function of the gland [1,2]. A main goal of therapy is to perform a sialolithotomy with retention of the gland and the restoration of salivary flow [73]. A newly developed method using filter paper incorporating the chromophore of melanoidin or stimuli such as capsaicin and citric acid can be useful for evaluation of residual salivary gland function and screening for hyposalivation [73]. Alternative therapies involve conservative measures such as hydration, heat, massage, and sialagogues might be effective measures along with flushing or milking the stone from the duct [7]. Systemic antibiotics may be beneficial, especially in cases with acute episodes of sialadenitis [1]. Sialoliths located within the gland or hilums are most commonly managed with a sialadenectomy. The decision to excise a gland is based on size of the sialolith and its location with the gland, as well as difficulty of retrieval of the salivary stone Figure 4 Final Specimen. Rogue intact sialolith and left submandibular gland. Figure 5 H&E Stain (A) – Chronic sialodenitis and dilated major salivary gland duct with epithelial hyperplasia and lymphoid follicles and chronic inflammatory cells in the duct wall (4x). (B) – Chronic sialodenitis and dilated major salivary gland duct with epithelial hyperplasia and lymphoid follicles and chronic inflammatory cells in the duct wall (10x). (C) – Chronic inflammatory cell infiltrate in submandibular gland destroying gland parenchyma. Figure 6 Cartoon schematic outlining treatment options for submandibular sialolithiasis. Central Gill et al. (2016) Email: Ann Otolaryngol Rhinol 3(8): 1128 (2016) 4/7 Table 1: Review of Giant Sialoliths. Study Gender Age (Years) Gland Location Size (mm) 1 Meyers (1942) [12] Male 50 Submandibular Duct 50 2 Mustard (1945) [13] Male 42 Submandibular Duct 56 3 Guernsey (1953) [9] Female 65 NR Parenchyma 33 4 Allen (1956) [14] Male 49 Submandibular Duct 35 5 Cavina/ Santoli (1965) [15] Male 59 Submandibular Duct 70 6 Cavina/ Santoli (1965) [15] Male 53 Submandibular Both 60 7 Hoggins (1968) [10] Male 52 Submandibular Parenchyma 50 8 Rust/ Messerly (1969) [16] Male 66 Parotid Duct 51 9 Rust/ Messerly (1969) [16] Male 58 Submandibular Parenchyma 35 10 Brusati (1973) [17] Male 55 Submandibular Parenchyma 31 11 Raskin, et al (1975) [18] Male 52 Submandibular Duct 55 12 Zakaria (1981) [19] Male 70 Submandibular Parenchyma 33 13 Koshal/ Naik (1982) [20] Male 40 Submandibular Duct 50 14 Isacsson/ Persson (1982) [21] Male 48 Submandibular Duct 36 15 Naraynsingh (1985) [22] Male 28 Submandibular Parenchyma 60 16 Frame/ Smith (1986) [23] Male 50 Submandibular Parenchyma 30 17 Kaltman/ Eichner (1987) [24] Male 53 Submandibular Parenchyma 45 18 Lakhoo/ Mannell (1989) 25] Male 37 Submandibular Duct 65 19 Tinsley (1989) [26] Male 48 Submandibular Parenchyma 50 20 Bamgbelu (1989) [27] Male 55 Submandibular Duct 35 21 Asfar, et al (1989) [28] Male 55 Submandibular Parenchyma 38 22 Hubar, et al (1990) [29] Male 65 Submandibular Duct 52 23 Martin, et al (1990) [30] Male 60 Submandibular Parenchyma 60 24 Akin/ Esmer (1991) [31] Male 45 Submandibular Parenchyma 45 25 Iqbal, et al (1992) [32] Female 48 Parotid Duct 30 26 Paul/ Chauhan (1995) [33] Male 45 Submandibular Duct 45 27 Udagatti/ Chandra (1997) [34] Male 75 Submandibular Parenchyma 60 28 Kesse, et al (1998) [35] Male 64 Parotid Parenchyma 50 29 Eiraku, et al (1999) [36] Male 56 Submandibular Duct 51 30 Bodner (2002) [37] Male 50 Submandibular Duct 50 31 Bodner (2002) [37] Male 46 Submandibular Duct 32 32 Bodner (2002) [37] Male 25 Submandibular Duct 32 33 Bodner (2002) [37] Male 45 Submandibular Duct 30 34 Siddiqui (2002) [38] Female 52 Submandibular Duct 30 35 Vittal et al (2002) [39] Male 70 Submandibular Duct 60 36 Sutay et al. (2003) [40] Female 22 Submandibular Parenchyma 37 37 Akimoto et al.(2004) [41] Male 70 Submandibular Duct 45 38 Raveenthiran/ Rao (2004) [42] Female 10 Submandibular Duct 35 39 Yildirim (2004) [43] Male 56 Submandibular Parenchyma 30 40 Chan/ Patel (2006) [44] Male 27 Submandibular Duct 35 41 Ledesma-Montes, et al (2007) [45] Male 34 Submandibular Duct 36 42 Alkurt/ Peker (2009) [46] Male 65 Submandibular Duct 31 43 Rai/ Burman (2009) [47] Male 60 Submandibular Duct 72 44 Patil, et al (2009) [48] Male 50 Submandibular Duct 38 45 Emegoakor, et al (2009) [49] Male 65 Submandibular Duct 50 46 Krishnan, et al (2009) [50] Male 41 Submandibular Duct 34 47 Huang, et al (2009) 4 [4] Male 57 Submandibular Duct 40 48 El Gehani, et al (2010) [51] Male 41 Submandibular Duct 35 49 El Gehani, et al (2010) [51] Male 48 Submandibular Parenchyma 30 50 Khen/ Abdeen (2010) [52] Male 53 Submandibular Duct 33 51 Gungormus et al. (2010) [53] Male 59 Sublingual Parenchyma 32 52 Silva-Junior et al. (2010) [54] Male 58 Submandibular Duct 35 53 Cottrell et al. (2011) [55] Male 75 Submandibular Duct 30 54 Leite et al. (2011) [56] Female 54 Submandibular Duct 35 Central Gill et al. (2016) Email: Ann Otolaryngol Rhinol 3(8): 1128 (2016) 5/7 55 Babu/ Jain (2011) [57] Male 50 Submandibular Duct 62 56 Iqbal, et al (2012) [58] Male 55 Submandibular Duct 35 57 Fowell/ MacBean (2012) [59] Male 58 Submandibular Duct 41 58 Rauso, et al (2012) [60] Male 56 Submandibular Duct 56 59 Tyagi, et al (2013) [11 ] Male 69 Submandibular Duct 35 60 Pandarakalam, et al (2013) [61] Male 68 Submandibular Duct 40 61 Goyal, et al (2013) [62] Male 40 Submandibular Duct 50 62 Singh (2013) [63] Male 55 Submandibular Duct 37 63 Banerjee et al.(2013) [64] Male 50 Submandibular Duct 35 64 Rodrigues (2014) 73 [65] Female 48 Submandibular Duct 45 65 Shahoon, et al (2015) [66] Male 25 Submandibular (Bilateral) Duct 50, 30 66 Shahoon, et al (2015) [66] Male 30 Submandibular Duct 83 67 Arslan, et al (2015) [2] Male 42 Submandibular Parenchyma 35 68 Sari/ Sahin (2015) [67] Male 55 Submandibular Duct 40 69 Demircan (2015) [68] Male 62 Submandibular Duct 30 70 Bhullar (2015) [69] Male 45 Submandibular Duct 31 71 Akinyamoju/ Adisa [70] Male 54 Submandibular Duct 44 72 Omezli et al. (2016) [71] Male 35 Submandibular Duct 37 73 Present Case Male 48 Submandibular Duct 57 Abbreviations: mm: millimeters; NR: Not reported and/or structural damage of the gland [1,2]. The excision of the submandibular gland has low morbidity, with few complications [74]. More recent minimally invasive surgical techniques used in the treatment of sialolithiasis include surgical sialolithotomy with or without sialodochoplasty, sialoendoscopy with sialolithotomy, intracorporeal or extracorporeal lithotripsy [7]. For giant sialoliths, Transoral sialolithotomy with sialodochoplasty or sialadenectomy may be the preferred management [73]. The rate of recurrence for sialolithiasis has been reported to be 8.9% [75,76]. Recurrence of sialoliths after gland excision has also been reported [77,78]. Failure to recognize stones upon exploration would be the most simplistic explanation; however it has been proposed that there may be a communication between the sublingual glandular complex and the submandibular duct allowing for future sialolith formation. CONCLUSION Given the size of the stone, dilation of the duct, lack of function of the gland due to its chronic state of sialodenitis, removal of the gland became our most predictable treatment option for this particular case. Treatment of Giant sialoliths, although rare, especially in the setting of chronic sialodenitis should be considered and treated appropriately depending on presentation.