Case 5

• 42 YO lady • Abnormal vaginal bleeding• US endovaginal : endometrial polyp• Hysteroscopy and endometrial curettage :

endometrial polyp located in the uterineisthmus

Endometrial curettage : 1.5 X

Normal proliferative endometriumNumerous polypoid fragments

Polypoid fragments

Numerous irregular, branching endometrial glands haphazardly distributed with a complex architectureStromal component

Fibro-vascular tissueCrowded glands

Cytologic atypia with nuclear stratification, vesicular and rounded nuclei and nucleoli

sStromal component : composed of interlacing fascicles of smooth muscle cells

Diagnosis?

• Atypical Polypoid Adenomyoma (APA)

WHO 2003 mixed mullerian tumors

Benignepithelium

Malignantepithelium

Benign stroma AdenofibromaAdenomyoma(APA)

Carcinofibroma(?)

Malignantstroma

Adenosarcoma Carcinosarcoma

Polypoid adenomyoma

• A rare form of endometrial polyp (1%)• Stroma is composed of smooth muscle rather

than fibroblastic or fibro-vascular tissue • Two variants :

– Classic or typical– Atypical

• Associated with uterine adenomyosis (30%)

Polypoid adenomyomaadenomyomatous polyp

• Was first described by Mazur in 1981

• Two largest series 27 (Young et al, 1986) and 55 (Longacre et al, 1996) cases

• Perimenopausal and premenopausal (nulliparous) women (mean 40 [21-81 years]),

• Few cases associated with Turner syndrome

• May be a complication of long-term estrogenic stimulation of the endometrium (10% of cases)

• Uterine bleeding

Atypical polypoid adenomyoma

APA : gross

• Endometrial solitary polyp (1 to 9 cm, usually < 2 cm)

• May be multiple (10%)

• Classically located in the lower uterinesegment– isthmus : 57%

– cervix : 21%

– fundus : 21%

APA : histology

• Usually seen on curettage: fragment of a polypoid lesion in a background of uninvolved endometrium

APA: 13% found on hysterectomy

APA : histology

• Three signs:1.Glandular crowding with atypical cytology

(atypical complex hyperplasia)2.Morular or squamous metaplasia (90%)

with central necrosis of squamous nests (15%)

3.Stromal component composed of smooth muscle

APA : complex architecture

Stratification, vesicular nuclei, nucleoli

APA: squamous metaplasia

Smooth muscle stroma : desmin +short interlacing fascicles, no atypia and <2mitoses/10HPF

APA : differential diagnosis

1. Typical (classical) polypoid adenomyoma– no complexity of

glandular component– no cytologic atypia

APA : differential diagnosis

2 – Endometrioid adenocarcinoma with myometrial invasion:- no or little cribriforming- no fibroblastic stromal reaction- short interlacing immature smooth muscle fascicle, h-caldesmon negative (long elongated bundles of normal myometrium h-caldesmon +) Horita et al, 2011

APA - prognostic• Well circumscribed, but may show

superficial myoinvasion in cases with more complex architecture (20%)

• Coexistence with well differentiated adenocarcinoma in the APA or the adjacent endometrium (9 – 17% of cases)

• Recurrences or persistence disease after curettage 45% (Longacre et al, 1996) and 30% (review by Heatley 2006)

• No dead of disease

APA – prognostic and treatment

• Benign• Longacre et al 1996 proposed that cases

with markedly complex glands be designated as « APA-of low malignant potential »

• Simple hysterectomy • Hysteroscopic resection for patients who

desire to preserve fertility Matsumoto et al, 2013

TAKE HOME MESSAGESAtypical Polypoid Adenomyoma

• Endometrial polyp in the lower uterine segment

• 40 year-old premenopausal lady• Numerous glands with complex

architecture, cytologic atypia• Squamous metaplasia• Smooth muscle bundles in the stroma