MUCOCELE & RANULA

MUCOCELE คือ ช่องว่างภายในเนื้อเยื่อที่มีน้ำลายขังอยู่ เป็นถุงน้ำที่เกิดสัมพันธ์กับ minor salivary gland แบ่งเป็น 2 ชนิดตามสาเหตุการเกิด คือ Extravasation mucocele (Mucous extravasation cyst) 2. Retention mucocele (Mucous retention cyst )

Extravasation mucocele The leakage of fluid from the ducts or acini into the surrounding tissue เกิดจาก physical trauma ทำให้มีการฉีกขาดของducts Hx of rupture, collapse & refilling 90% of salivary mucocele Children, young adult (peak in second decade)

Extravasation mucocele Histopathology : mucin-filled cystic cavity granulation tissue lining surrounded by a condensation of connective tissue with varying amounts of inflammation & vascular engorgement No epithelium lining - - Pseudocyst

Retention mucocele Partial obstruction of duct ทำให้ขวางการหลั่งน้ำลาย เกิดเป็น ductal dilation & surface swelling อาจเกิดจาก low-grade chronic superficial irritation ได้ พบน้อยกว่า extravasation type > 50 years of age

Retention mucocele Histopathology : คล้าย extravasation type แต่ cavity บุด้วย ductal epithelial cells : stratified squamous epith. , columnar,cuboidal - - True cyst

ลักษณะทางคลินิก Soft , painless swelling Translucent deep blue to normal pink พบบ่อยที่ lower lip , cheek ,palate อาจพบได้ที่ ventral of tongue, incisal gland, retromolar pad

ลักษณะทางคลินิก Rarely present significant problem Discomfort, interference with speech/masticating/swallowing & external swelling depend on size & location

Treatment ตัดรอยโรคออกพร้อมกับ minor salivary gland ที่เกี่ยวข้อง

RANULA Plunging ranula(Deep ranula): คือ mucocele ที่เกิดในตำแหน่ง floor of mouth สัมพันธ์กับ sublingual gland เกิดจาก obstruction or disruption of sublingual ducts Plunging ranula(Deep ranula): คือ ranula ที่อยู่ลึกลงไปต่ำกว่า mylohyoid muscle และตามแนว fascial plane of neck

ลักษณะทางคลินิกl Histo: Unilateral, fluctuant, soft tissue mass ที่ floor of mouth Bluish, translucent swelling painless Histo: Most - - extravasation type แต่ก็พบแบบ mucous retention type ได้เช่นกัน

Most common origin of ranula 1. Deeper area of the body of sublingual gland 2. Retention cysts from Ducts of Rivini 3. Retention cysts of the opening of Wharton’s duct

Treatment Removal of sublingual gland along with excision of the cyst Marsupialization with sublingual gland excision Deep ranula : sublingual gland removal along with excision of the cyst

Marsupialization คือการเปิดฝาของถุงน้ำออกไป (unroofing procedure) เป็นการลดความดันภายในถุงน้ำ พิจารณาทำในกรณีที่มีถุงน้ำขนาดโตมาก ยากแก่การควักออกทั้งหมด เพราะอาจทำอันตรายต่ออวัยวะข้างเคียง

Marsupialization โดยการตัดเอาส่วน mucosa ที่ปกคลุมถุงน้ำออกไปพร้อมกับผนังถุงน้ำที่อยู่บริเวณนั้น จากนั้น ขอบของ mucosa จะถูกเย็บติดกับขอบของผนังถุงน้ำ ควรเปิดฝาเป็นวงกลม และให้มีขนาดโตเท่าที่จะทำได้ เพื่อป้องกันการเจริญเติบโตของผนังถุงน้ำมาติดกันอีก

CURRENT THERAPY : Mucoceles and Ranulas Harold D. Baurmash ,DDS J Oral Maxillofac Surg 61 : 369-378, 2003

Surgical Technique for the Management of Accessory Salivary Gland Mucoceles Lip, cheek, and palate Tongue

Lip, cheek, and palate Small lesion: completely excised, include the associated salivary gland tissue & marginal glands before primary closure Moderate sized lesion: dissection of the mucocele along with the servicing mucous glands

Lip, cheek, and palate Large lesion: Marsupialization excision problematic & risk vital structure # labial branch of mental nerve Reducing recurrence remove any projecting peripheral salivary gland before placement of interrupted marginal sutures Avoid injury to the other glands & ducts surgical injury is another cause of recurrence

Lip, cheek, and palate Nonmucous retention cyst involving the opening of Stensen’s duct : unroof the cyst insert a lacrimal probe into the duct lumen before the duct margins are sutured to the adjacent mucosa with fine interrupted gut sutures (Sialodochoplasty) F/U care - - salivary stimulating foods & duct dilation using lacrimal probe

Tongue Anterior lingual gland (Gland of Blandin-Nuhn): located on the inferior surface of tongue close to apex & midline covered by thin mucous membrane a compact package of smaller glands that open with several ducts

Tongue Small lesion: completely excised & primary closed Moderate to large lesion: unroof the lesion along its entire periphery to visualize remove all of the glands present

Tongue Moderate to large lesion: a tongue-retracting suture at tip of tongue 1-cm longitudinal incision through mucosa 0.25-inch plain gauze - - packed into cavity to restore the original peripheral configuration unroof lesion & remove all glandular tissue mucosa is undermined primary closure

Management of Ranula & Ranula-Like Lesions in the Oral Floor Simple marsupialization -> disfavor because of high recurrent rate(61 - 89%) Crysdale et al ,Catone et al & Bridger et al: “sublingual gland removal should be the primary treatment of all ranula”

Unroofing -> drainage of it contents Inferior compression by tongue during function will force the opposing granulation tissue walls together -> rapid healing with minimum fibrosis. Not eliminate source of leakage -> recurrence at a higher rate than reported

2 reasons for reconsidering sublingual gland removal as primary treatment 1.A number situations present as ranula that do not arise from the sublingual gland. 2.A slight variation to the standard marsupialization procedure can reduce the incident of recurrence to 10% to 12%.

Treating Ranula-Like Lesion Not Arising From the Body of the Sublingual Gland Mucocele of the incisal gland Retention cyst of Wharton’s duct Submandibular duct injury with salivary fluid leakage Retention cysts of the sublingual gland

Mucocele of the incisal gland Incisal gland: small group of mucous accessory glands on the floor of oral cavity behind lower incisors treated with unroofing & removal of all glandular tissue with or without peripheral margin suturing

Retention cyst of Wharton’s duct Small(0.5cm) to moderately sized(1.5cm) superficial Cyst-like lesions. Area of caruncular sublingualis extending posteriorly along the course of plica sublingualis.

- May simulate retention cysts of the ducts of Rivini. - Examination of cystic secretions help to differentiate - Wharton’s duct retention cysts -> assosiated with obstructive submandibular gland symptoms & never larger than 1.5 cm.

Treatment procedure - Unroofing the cyst, inserting lacrimal probe into duct lumen & sialodochoplasty - Postoperative care -> sour food & ductal dilation with probes.

Submandibular duct injury with salivary fluid leakage - Iatrogenic injury to antr section of wharton’s duct. Treatment - Locate the damaged duct after excising overlying mucosa.

- Isolate the duct & milk the gland -> show the extent of injury. - Sialodochoplasty Longitudinal incision(1-1.5 cm) in supr wall of duct, postr to the leakage Insert lacrimal probe into lumen, directed toward the gland.

Suture the margins of duct to adjacent mucosa with 2 gut sutures Single suture -> placed through supr wall at proximal end of incision to engage overlying mucosa Postoperative care

Retention cysts of the sublingual gland Small to moderate size Treatment : unroofing with or without peripheral sutures Acini -> atrophy or secrete through Bartholin’s duct Rarely recur

Treating Ranula from the body of the sublingual gland “Why the majority of large ranulae which originate from the body of the sublingual gland, develop without any history of trauma?”

Harrison & Garrett: -effect of ligating the sublingual duct in cats with the chorda tympani nerve intact. -In all cases, initial extravasation of mucus -> first 20 days -One half developed mucoceles -Duct obstruction led to the extravasation of mucous from ruptured acini rather than from duct leakage

Glen, a veterinarian: -Sialograms on dogs with ranulae -Ducts showed no evidence of leakage

Trauma -> initiating factor in ranula Most cases -> iatrogenic Most common cause: after sialolithomy>>improper incisional design or excessive trauma to gland Wharton’s duct -> on medial surface of sublingual gland Incision->medial & parallel to the plica sublingualis

Incision lateral to the plica-> injure the gland-> ranula on lateral of gland Correct incision -> dissection at antr portion of duct(supr in oral floor) Excessive glandular disruption->ranula medial to gland Mucoceles develop up to 3 months after stone removal

Harrison & Garrett: One half of cats failed to develop mucoceles Showed severe inflammatory reaction # macrophages Extensive connective tissue response sealed the leakage-> atrophy of acini

This observation was the rationale for modifying the standard marsupialization technique to decrease recurrence rate Adding gauze packing into cavity after unroofing -> pressure of pack seals the leak.

Refined marsupialization tectnique with packing Insert lacrimal probe into wharton’s duct for protection Unroof the cyst. Cavity should be packed to its depth Interrupted suture around margins. Keep the packing in place 7-10 days

Variations of the Deep Ranula Superficial dissecting ranula- -bilateral & exceptionally large in size Excessive amounts of mucous leakage & more resistance inferiorly -> excessive superior pressure But origin is always unilateral and the ranula arises from deep medial surface of sublingual gland The side of origin appear a bit more prominent

Procedure - Place tongue suture Horizontal mucosal incision across midline Unroof the cyst Insert gauze packing to the full depth of the site of origin Mucosal margins are sutured with interrupted absorbable sutures.

Plunging ranula: Large perforation of mylohyoid muscle -> fluid enter the submadibular space Large external swelling with intraoral mass in the oral floor CT or MRI -> aid in diagnosis

Recommended primary treatment->Removal of sublingual gland. Additional indications: Recurrent ranula after a single marsupialization with packing Hypertrophied sublingual glands that interfere with prosthetic reconstruction

Technique Sublingual gland-> intraoral removal Primary attention – Avoid injury to lingual nerve or Wharton’s duct Insert lacrimal probe before incision and keep in place for entire procedure -> make the duct identifiable Longitudinal incision posteroanterior direction midway between plica sublingualis & lingual of mandible (2nd molar to cuspid area)

Dissection begins on lateral side of the antr 2/3 of gland and is carried down to surface of mylohyoid muscle Place several retracting suture to facilitate the dissection of medial surface of the antr 2/3 of gland Moistened gauze pad or “peanut” in front of elevator -> safe blunt dissection Use retraction sutures to lift gland superiorly & anteriorly

Continue blunt dissection on medial postr portion of gland until lingual nerve is identified & isolated Remove the gland from oral floor after 1 week of healing, use lacrimal probe to prevent ductal stenosis

References Dym H, Ogle OE: Atlas of Minor Oral Surgery. Philadelphia, W.B.Saunders,2001 Bailey BJ: Surgery of the oral cavity. 1989 Yoel J: Pathology and Surgery of the salivary glands. Thomas ,1975 Baurmash HD: Mucoceles and Ranulas. J Oral Maxillofac Surg 61:369-378,2003

ผศ.ทพ.อนันต์ พงศ์สุวารียกุล Special Thanks ผศ.ทพ.อนันต์ พงศ์สุวารียกุล