Low-grade mucinous appendiceal neoplasm mimicking an ovarian lesion: A case report and review of literature

Table 1 Appendiceal neoplasms mimicking adnexal lesions (cases identified by the PubMed search, published in English language until January 2021)

Case	Age	Cardinal symptom	Clinical context	Imaging modality	Tumor marker	Presumed diagnosis	Treatment	Appendix: Histopathology
1[24]	32	Abdominal pain	Acute abdomen (38 wk pregnancy)	US (cystic mass 32 mm × 35 mm × 59 mm)	N/A	Right ovarian torsion	Laparotomy: Appendectomy C-Section	Mucocele (torsion)
2[25]	49	Pelvic pain	Chronic pain (1 yr)	US (heterogenous mass 70 mm × 35 mm × 40 mm). MRI (cystic mass 70 mm × 63 mm × 29 mm)	CEA 10.5 μg/L (↑). CA125 normal	Right adnexal mass of paraovarian origin	Laparoscopy: Appendectomy. Peritoneal washing	LAMN. Peritoneal citology: Negative
3[2]	81	Abdominal pain	Chronic pain (several months)	US (heterogenous cystic mass 110 mm × 90 mm). MRI (heterogenous cystic mass 120 mm × 100 mm)	CA125 13.18 U/mL. CA19.9 20.8 U/mL. CEA 1.76 ng/mL. CA15.3 6.7 U/mL	Right adnexal mass	Laparotomy: Appendectomy and a right hemicolectomy with ileo-transverse anastomosis. Total abdominal hysterectomy and bilateral salpingo-oophorectomy due to pelvic organ prolapse	Appendiceal mucinous neoplasm with low malignancy potential
4[17]	61	Incidental imaging finding	Preventive gynecological check-up	US (heterogenous solid mass 104 mm × 40 mm)	CA19.9 40 U/mL (↑). CA125 9 U/mL. CA15.3 13 U/mL. AFP 2 ng/mL	Left adnexal mass	Laparotomy: Appendectomy. Excisional biopsy of the omentum	LAMN
5[26]	41	Pelvic pain	Chronic pain	US (cystic mass 60 mm × 28 mm). MRI (70 mm × 40 mm × 30 mm)	CEA and CA19.9 normal	Right adnexal mass	Laparoscopy converted to laparotomy: Right hemicolectomy with side to side ileocolic stapler anastomosis	LAMN
6[27]	15	Abdominal pain	Acute abdomen	US; CT (no precise description reported)	N/A	Right ovarian torsion	Laparoscopy: Appendectomy	Mucocele
7[28]	46	Incidental pelvic examination finding	Preventive gynecological check-up	US (cystic mass 115 mm × 40 mm)	N/A	Right adnexal mass (hydro-pyosalpinx, tubo-ovarian abscess or ovarian cyst)	Laparotomy: Appendectomy	Mucocele
8[15]	71	Pelvic pain	Acute pain	US (cystic mass 50 mm × 70 mm). MRI (cystic mass 40 mm × 80 mm)	CA125 9.1 U/mL. CA19.9 5.09 U/mL. AFP 2.4 ng/mL. β-hCG 0.01 mIU/mL	Righ adnexal mass	Laparotomy: Appendectomy. Total abdominal hysterectomy and bilateral salpingo-oophorectomy due to pelvic organ prolapse	Mucocele
9[29]	80	Abdominal pain	Chronic pain (several months)	US (mixed echogenic mass 61 mm × 43 mm × 51 mm). CT (calcified cyst 70 mm × 60 mm × 50 mm)	CA125 normal	Righ adnexal mass (ovarian cyst)	Laparotomy: Appendectomy	Mucinous cystadenoma
10[30]	61	Pelvic pain	Chronic pain (several months)	US (cystic mass). CT (homogenous mass 110 mm × 35 mm)	Normal (not specified)	Right adnexal mass (ovarian cyst or hydrosalpynx)	Laparoscopy: Appendectomy	LAMN
11[31]	26	Pelvic pain	Chronic pain	US (cystic mass 30 mm × 30 mm)	N/A	Right adnexal mass (ovarian cyst)	Laparoscopy: Appendectomy	Mucinous cystadenoma with mild-moderate dysplasia
12[16]	70	Incidental pelvic examination finding	Preventive gynecological check-up	US (solid mass 60 mm × 60 mm × 40 mm)	CA125 120 mg/dL (↑). CEA normal	Right adnexal mass	Laparotomy: Appendectomy. Total abdominal hysterectomy and bilateral salpingo-oophorectomy.	Mucinous cystadenoma
13[32]	68	Incidental pelvic examination finding	Abnormal uterine bleeding	US (cystic mass 39 mm)	N/A	Right adnexal mass (ovarian cyst)	Laparoscopy: Appendectomy	Mucocele
14[18]	50	Pelvic pain	-	US (tubular mass 96 mm × 40 mm × 33 mm). MRI (no precise description reported)	N/A	Left adnexal mass (hydrosalpynx)	Robotic: Appendectomy Right hemicolectomy	Low grade mucinous adenocarcinoma
15[33]	42	Incidental imaging finding	1st trimester bleeding	US (cystic mass 120 mm × 108 mm × 58 mm)	CA125 16 U/mL	Right adnexal mass (ovarian cyst)	Laparotomy: Appendectomy	Mucocele
16[34]	31	Pelvic pain	Fever	US; MRI (no precise description reported)	CA125 12.2 U/mL. CEA 5.2 U/mL. CA19.9 0.8 ng/mL	Right adnexal mass (hydrosalpynx)	Laparotomy: Appendectomy	Mucocele
17[35]	79	Incidental imaging finding	Preventive gynecological check-up	US (uniloculated mass, characterizedby dishomogeneous content, distal shadowing 59 mm × 43 mm × 40 mm). MRI (cystic mass 80 mm)	CEA 1.26 ng/mL. CA125 8.1 U/mL. CA19.9 3.44 U/mL. CA15.3 14.1 U/mL	Right adnexal mass (ovarian cyst)	Laparoscopy: Appendectomy	Mucocele
18[36]	80	Pelvic pain	Chronic pain	US (cystic/solid mass 83 mm × 65 mm × 64 mm). CT (cystic mass 100 mm × 80 mm)	CEA 54.2 ng/mL	Right adnexal mass	Laparotomy: Appendectomy. Omentectomy, total abdominal hysterectomy, and bilateral salpingo-oophorectomy	LAMN
19[37]	83	Incidental imaging finding	Preventive gynecological check-up	US (cystic/solid mass 87 mm). MRI (cystic mass 90 mm)	CEA 5.3 ng/mL (↑). CA15.3 31.4 U/mL	Right adnexal mass	Laparotomy: Appendectomy	LAMN
20[38]	78	Asymptomatic	Known adnexal mass on ultrasound follow-up	US (cystic mass 58 mm × 42 mm × 35 mm). MRI (bilocular cystic mass 41 mm × 19 mm)	CEA, CA125 and CA19.9 normal	Right adnexal mass	Laparotomy: Appendectomy. Total abdominal hysterectomy and bilateral salpingo-oophorectomy due to pelvic organ prolapse.	Mucinous cystadenoma
21[39]	28	Pelvic pain	Acute abdomen	CT (cystic mass 33 mm × 50 mm)	N/A	Right adnexal mass (ovarin cyst rupture)	Laparoscopy: Appendectomy	Mucocele (torsion: Hemorrhagic transmural necrosis)
22[40]	36	Pelvic pain	-	US (cystic complex mass)	CEA ↑; CA19.9 ↑	Right adnexal mass	Laparotomy: Appendectomy	Mucinous cystadenoma
23[41]	75	Asymptomatic	Adnexal mass on ultrasound (investigation due to CEA↑)	US. CT (cystic mass 90 mm)	CEA 17.7 ng/mL (↑). CA125 and CA19.9 normal	Right adnexal mass (ovarian malignancy)	Laparotomy: Appendectomy	Mucinous cystadenoma

↑: Above the upper limit of normal; AFP: Alpha-Fetoprotein; C-section: Cesarean section; CA125: Cancer antigen 125; CA15.3: Cancer antigen 15.3; CA19.9: Carbohydrate antigen 19.9; CEA: Carcinoembryonic antigen; CT: Computed Tomography; MRI: Magnetic resonance imaging; N/A: Not available; US: Ultrasound; LAMN: Low-grade mucinous appendiceal neoplasm; β-hCG: β-human chorionic gonadotropin.