Appendiceal Mucoceles - Lieberman's eRadiologyeradiology.bidmc.harvard.edu/learningLab/musculo/Pernar.pdf · mucocele ’ 5 Luise Pernar ... • Appendiceal mucoceles are rare and

Luise Pernar, HMS IVGillian Lieberman, MD

Appendiceal Mucoceles

Luise Pernar, Harvard Medical School IV

Gillian Lieberman, MD

September 2006

2


Patient 1: JH

• 68 yo woman with history of myelodysplastic syndrome

• Admitted to BIDMC for induction of chemotherapy for acute myelogenous leukemia

• During course of induction patient developed fever and neutropenia

• CT scan was performed to search for possible site of infection

3


Patient 1: JH - CT

PACS, BIDMC - Courtesy of Karen Lee, MD

Cecum

Terminal Ileum

Cyst

(27 HU)

Focal wall calcification

4


Patient 1: JH - CT

• Findings summary:– Cystic structure adjacent to cecum near

ileocecal junction; appendix not seen separately

– Density ~ 27HU– Suggestion of rim-enhancement of cystic wall

with focal calcification– No surrounding stranding suggestive of

inflammationOfficially read as: ‘likely an appendiceal

mucocele’

5


Patient 2: LC

• 54 yo woman with history of breast cancer diagnosed in 2000; treated with L mastectomy, chest wall radiation therapy, tamoxifen

• Presented with complaints of abdominal distention and mild abdominal pain

• Paracentesis yielded 1.5L of ascites fluid with malignant cells

• CT scan was performed to determine possible source

6


Patient 2: LC - CT

PACS, BIDMC - Courtesy of Karen Lee, MD

Cecum

Terminal Ileum

Cyst (34 HU)

Rim-enhancement

Ascites fluid

Omental caking

7


Patient 2: LC - CT

• Findings summary:– Cystic structure adjacent to cecum and ileum;

appendix not seen separately – Density ~ 34HU– Suggestion of rim-enhancement of cystic wall– No surrounding stranding suggestive of

inflammation– Omental caking and ascites

Officially read as: ‘could represent an appendix mucocele’

8


Appendiceal Mucocele - Definition

• Appendiceal lesion characterized by – Appendiceal lumen dilation– Mucosal lining alteration– Hypersecretion of mucus– Potential for extension outside the appendix

This definition is problematic since it is descriptive and does not convey information about the primary underlying disease

Higa et.al. Cancer 1973

9


Appendiceal Mucocele - Definition• Histologically mucoceles can be divided into

– Mucosal hyperplasia (25%)– Mucinous cystadenoma (63%)– Mucinous cystadenocarcinoma (12%)– Retention cysts have also been described

• Malignancy of mucoceles has been variably defined by – Histologic type of epithelial cells in resected specimen– Dissection of the appendiceal wall by mucin– Presence of epithelial cells in mucin if there has been

egress into the peritoneal cavity

Lo and Sarr Hepatogastroenterology 2003; Higa et.al. Cancer 1973

10


Incidence and Diagnosis• Frequency: 0.1% - 0.4% of all appendectomy specimens

show findings consistent with mucocele• F:M = 1.2-4:1• Age at diagnosis 50’s-60’s• 49% symptomatic

– Malignant appendiceal mucoceles more frequently become symptomatic

– Common presenting complaints are • abdominal pain (27%)• palpable abdominal mass (16-25%)• abdominal distention (14%)• weight loss (10%)

• Laboratory analysis may show elevated CEA, WBC, and ESR

Stocchi et.al. Arch Surg 2003; Lo and Sarr Hepatogastroenterology 2003; Blair et.al. Am J Surg 1993; Landen et.al. Surg Gynecol Obstet 1992

11


Differential Diagnosis• Intraperitoneal

– Other appendiceal neoplasm (lipoma, fibroma, neuroma, carcinoid, lymphoma)

– Appendicitis– Cyst (ovarian, mesenteric, omental)– Mesenteric hematoma or tumor– Abdominal abscess– Hydrosalpinx

• Retroperitoneal– Inflammation– Tumor– Hemorrhage

Horgan et.al. AJR 1984

12


Imaging of Mucoceles• Correct preoperative diagnosis is key for

appropriate surgical intervention (more on this later)

• Diagnostic imaging modalities used in preoperative diagnosis include– US– X-ray– Barium enema– Endoscopy– CT

13


Mucocele on US – Companion Patient 1

Trans-abdominal US showing:

• Elongated, unilocular cystic structure with internal echos

• Enhanced through- transmission suggested cyst is fluid-filled

• Indistinct cystic wall

Pickhardt et.al. RadioGraphics 2003

14




• Elongated, unilocular cystic mass (M) with internal echos

• No distinct cyst wall• No posterior or lateral

shadowing

Sasaki et.al. Abdom Imaging 2003

15




• Cystic mass with echogenic layers ‘onion-skin’ sign

Caspi et.al. J Ultrasound Med 2004

16


Mucocele on X-ray – Companion Patient 4

Coned-down plain film of RLQ showing:

• Round mass (Arrowheads)

• Curvy-linear calcifications (White arrows)


17


Mucocele on X-ray – Companion Patient 5

Plain film of RLQ showing:

• Rounded mass suggested by wall cacifications (Arrows)

Higa et.al. Cancer 1973

18


Mucocele on Barium Enema – Companion Patient 6

Single contrast barium enema showing:

• Smooth, broad-based filling defect (Arrowhead) in the medial cecum adjacent to the ileocecal valve


19


Mucocele on Barium Enema – Companion Patient 7

Air-barium double contrast enema showing:

• Smooth, submucosal filling defect (M) in the medial cecum


20


Mucocele on Colonoscopy – Companion Patient 6

Colonoscopy, performed on patient 6 seen previously, showing:

• Bulbous, smooth submucosal lesion (M) protruding into the cecum

• Mass’s movement with respiration is thought classic for a mucocele


21


Mucocele on Colonoscopy – Companion Patient 8

Colonoscopy showing:• Bulbous, smooth

submucosal lesion protruding into the cecum at the site of the appendiceal orfice

• Appendiceal orfice seen at the center of the mound is the ‘volcano’ sign considered classic for a mucocele

Zanati et.al. Gastrointest Endosc 2005

22


Mucocele on CT – Companion Patient 6

CT scan, of patient 6 seen previously, showing:• Cystic lesion (Arrowhead) adjacent to cecum extending into the

peritoneal cavity (Arrow)• Density range for mucoceles seen on CT ~ 10-45HU• Note absence of peri-appendiceal inflammation or abscess


23


Mucocele on CT – Companion Patient 9

CT scan showing:• Low-density, well-

capsulated mass (Arrow) adjacent to the cecum in the expected location of the appendix

Sasaki et.al. Abdom Imaging 2003

24


Imaging of Mucoceles – Summary of Findings

• US – Elongated, unilocular cyst-like mass with internal echos; indistinct wall; ‘onion-skin’ sign may be pathognomonic

• X-ray – RLQ rounded mass with curvilinear calcification• Barium enema – Smooth, broad-based filling defect in

the cecum• Endoscopy – Bulbous, smooth, submucosal lesion

protruding into the cecum near site of the appendiceal orfice; ‘volcano sign’ and movement of the mass with respirations are considered classic for appendiceal mucocele

• CT – RLQ mass adjacent to the cecum with low- attenuating content (0-45HU) and wall calcification

Zanati et.al. Gastrointest Endosc 2005; Caspi et.al. J Ultrasound Med 2004; Pickhardt et.al. RadioGraphics 2003; Sasaki et.al. Abdom Imaging 2003; Higa et.al. Cancer 1973

25


Why Pre-op Diagnosis?• Feared complication of appendiceal mucocele,

due to any cause, is PSEUDOMYXOMA PERITONEI

– Diffuse, gelatinous, cellular ascites– Origin thought to be

• Dissemination of mucinous cells from appendiceal mucocele due to rupture of appendix or metastatic spread OR

• Neoplastic transformation of peritoneum following mucinous metaplasia of mesothelium

– Often fatal without treatment as it causes intestinal obstruction

Hinson and Ambrose Br J Surg 1998; Prayson et.al. Am J Surg Pathol 1994

26


Pseudomyxoma Peritonei on US – Companion Patient 10

Rectal ultrasound showing:

• Thick, gelatinous fluid (F) in the pouch of Douglas

Khan et.al. Ultrasound Obstet Gynecol 2002

27


Pseudomyxoma Peritonei on CT – Companion Patient 11

CT scan showing:• Diffuse intraperitoneal

locules with mass effect on adjacent bowel

• Bowels do not float centrally

• Omental caking is present


28


Pseudomyxoma Peritonei on CT – Companion Case 12

CT scan showing:• Scalopping of solid

organs by mucinous implants

• Septal calcifications in mucinous fluid (Arrowheads)


29


• US – Thick gelatinous fluid; usually not mobile with maneuvers; fluid septations may be seen

• CT – Increased abdominal girth; diffuse intraperitoneal locules; mass-effect and distortion of bowel; scalloping of surfaces of solid organs

Imaging of Pseudomyxoma Peritonei – Summary of Findings

Pickhardt et.al. RadioGraphics 2003; Khan et.al. Ultrasound Obstet Gynecol 2002; Dachman et.al. AJR 1985

30

Luise Pernar, HMS IVGillian Lieberman, MD Treatment

Dhage-Ivatury and Sugarbaker J Am Coll Surg 2006; Witkamp et.al. Br J Surg 2001

Mucocele Diagnosed Pre-operatively?

Perform laparotomy•To prevent mucocele rupture•To allow thorough examination of peritoneal cavity for mucinous fluid

If employing laparoscopic approach, convert to laparotomy

• Appendectomy typically sufficient• Proceed to right hemicolectomy if

•Appendiceal or ileocecal lymph nodesare positive

•Resection margin is positive

• If no fluid is present workup is complete• If fluid is present

• Harvest all mucinous fluid• Submit to pathology for examination

for epithelial cells

If epithelial cells are present• Diagnose pseudomyxoma peritonei• Refer patient for

•debulking surgery (complete resection of gelatinous masses, greater omentum, major viscera, as appropriate)

•Intraperitoneal chemotherapy (mitomycin C +/- 5-fluorouracil)

Yes No

31


Outcomes• 91-100% survival after resection of mucocele

due to mucosal hyperplasia, mucinous cystadenoma, and mucinous cystadenocarcinoma if not complicated by pseudomyxoma peritonei

• 25-33% survival in presence of pseudomyxoma peritonei

• Debulking surgery with intraperitoneal chemotherapy yields 3 year survival between 61-86% with an associated 35% risk of morbidity including bowel perforation, fistula formation and anastomotic leak

Dhage-Ivatury and Sugarbaker J Am Coll Surg 2006; Witkamp et.al. Br J Surg 2001; Sugarbaker and Jablonski Ann Surg 1995; Landen et.al. Surg Gynecol Obstet 1992; Higa et.al. Cancer 1973

32


Summary

• Appendiceal mucoceles are rare and are often found incidentally; incorrect intraoperative handling may lead to major complications

• Suggestive and characteristic imaging findings can help establish the pre-operative diagnosis of mucoceles highlighting the role radiologists play in pre-operative planning and in ensuring good patient outcomes

33

Luise Pernar, HMS IVGillian Lieberman, MD Bibliography

• Blair NP; Bugis SP; Turner LJ; MacLeod MM. Review of the pathologic diagnoses of 2,216 appendectomy specimens. Am J Surg (1993) 165: 618-620.

• Caspi B; Cassif E; Auslender R; Herman A; Hagay Z; Appelman Z. The onion skin sign; a specific sonographic marker of appendiceal mucocele. J Ultrasound Med (2003) 23: 117-121.

• Dachman AH; Lichtenstein JE; Friedman AC. Mucocele of the appenidx and pseudomyxoma peritonei. AJR (1985) 144: 923-929.

• Dhage-Ivatury S; Sugarbaker PH. Update on the surgical approach to mucocele of the appendix. J AM Coll Surg (2006) 202: 680-684.

• Higa E; Rosai J; Pizzimbono CA; Wise L. Mucosal hyperplasia, mucinous cystadenoma, and mucinous cystadenocarcinoma of the appendix; a re-evaluation of the appendiceal mucocele. Cancer (1973) 32: 1525-1541.

• Hinson FL; Ambrose NS. Pseudomyxoma peritonei. Br J Surg (1998) 85: 1332-1339.• Horgan JG; Chow PP; Richter JO; Rosenfield AT; Taylor KJW. CT and sonography in the recognition of mucocele

of the appendix. AJR (1984) 143: 959-962.• Khan S; Patel AG; Jurkovic D. Incidental ultrasound diagnosis of pseudomyxoma peritonei in an asymptomatic

woman. Ultrasound Obstet Gynecol (2002) 19: 410-412.• Landen S; Bertrand C; Maddern GJ; Herman D; Pourbaix A; deNeve A; Schmitz A. Appendiceal mucolceles and

pseudomyxoma peritonei. Surg Gynecol Obstet (1992) 175: 401-404.• Lo NS; Sarr MG. Mucinous cystadenocarcinoma of the appendix; the controversy persists: a review.

Hepatogastroenterology (2003) 50: 432-437.• Pickhardt PJ; Levy AD; Rohrmann CA; Kende AI. Primary neoplasms of the appendix: radiologic spectrum of

disease with pathologic correlation. RadioGraphics (2003) 23: 645-662.• Prayson RA; Hart WR; Petras RE. Pseudomyxoma peritonei; a clinicopathologic stduy of 19 cases with emphasis

on site of origin and nature of associated ovarian tumors. Am J Surg Pathol (1994) 18: 591-603.• Sasaki K; Komatsuda T; Suzuki T; Konno K; Ohtaka M; Sato M; Ishida J; Sakai T; Watanabe S. Appendiceal

mucocele: sonographic findings. Abdom Imaging (2003) 28: 15-18. • Stocchi L; Wolff BR; Larson DR; Harrington JR. Surgical treatment of appendiceal mucocele. Arch Surg (2003)

138: 585-590.• Sugarbaker PH; Jablonski KA. Prognostic features of 51 colorectal and 130 appendiceal cancer patients with

peritoneal carcinomatosis treated by cytoreductive surgery and intraperitoneal chemotherapy. Ann Surg (1995) 221: 124-132.

• Witkamp AJ; de Bree E; Kaar MM; van Slooten GW; van Doevorden F; Zoetmulder FAN. Extensive surgical cytoreduction and intraoperative hyperthermic intraperitoneal chemotherpay in patients with pseudomyxoma peritonei. Br J Surg (2001) 88: 458-463.

• Zanati SA; Martin JA; Baker JP; Streutker CJ; Marcon NE. Colonoscopic diagnosis of the mucocele of the appendix. Gastrointest Endosc (2005) 62: 452-456.

34


Acknowledgement

Thank you:• Karen Lee, MD – for giving me great

cases• Gillian Lieberman, MD – for directing and

teaching a rotation I wish I had taken earlier

• Pamela Lebkowski – for outstanding support and organization

• Larry Barbaras

Documents

Appendiceal Mucoceles - Lieberman's eRadiologyeradiology.bidmc.harvard.edu/learningLab/musculo/Pernar.pdf · mucocele ’ 5 Luise Pernar ... • Appendiceal mucoceles are rare and