endometrial epithelial anomalies

Examples

  metaplasia of the endometrium
 endometrial atrophy
 endometrial hyperplasia
 endometrial dysplasia

Evaluation of endometrium (Sternberg approach)

Reference : Mills, SE: Sternberg’s Diagnostic Surgical Pathology (4th Ed); Lippincott Williams & Wilkins, 2004

Based on low power microscopic appearance

 Pattern 1: proliferations composed of glands and supportive non-neoplastic endometrial stroma ; must evaluate gland to stroma ratio , glandular and stromal features , appearance of vessels and pattern uniformity

• Gland to stroma ratio:
  • 1:1 associated with normal cycling endometrium , dysfunctional uterine bleeding and infertility
  • Glands > stroma associated with menstruation , late secretory phase , endometrial hyperplasia and endometrial carcinoma
  • Glands @<@ stroma associated with normal decidua , atrophy and monophasic stromal proliferations

• Glandular features:
  • Must evaluate cytologic features and architecture of glands to determine if endometrial atrophy, weakly proliferative endometrium , proliferative endometrium , presence of endometrial cytologic atypia , secretory endometrium (early, mid-, late), Arias-Stella reaction , disintegrating glands / shedding and budding or branching of glands

• endometrial stromal features:
• Usual stroma in proliferative phase has minimal cytoplasm and spindled or oval nuclei ; in secretory phase or pregnancy , has decidual changes of abundant eosinophilic or clear cytoplasm , large round / oval nucleus

• endometrial vasculature :
  • In proliferative phase , vessels are delicate branching network throughout endometrial stroma
  • secretory phase vessels have thicker walls, are coiled (aka spiral arteries )
  • thick walled vessels in fibrotic stroma are characteristic of endometrial polyp

• Pattern uniformity:
  • cycling endometrium has uniform pattern throughout, except for lower uterine segment / isthmus (spindled stromal cells separated by collagen, hybrid endocervical-endometrial glands) and stratum basalis layer (unresponsive to hormones, appears weakly proliferative throughout menstrual cycle )

 Pattern 2: biphasic proliferations of glands and abundant stroma (possibly neoplastic stroma )

• Includes endometrial polyp , atypical polypoid adenomyoma , MMMT, adenosarcoma , sarcoma , endometrial stromal neoplasms and adenomatoid tumor

 Pattern 3: predominantly endometrial monophasic spindle cell proliferations

• Includes endometrial smooth muscle tumors, endometrial stromal tumors, spindled epithelial tumors, pure heterologous uterine sarcomas and undifferentiated sarcoma
• endometrial epithelial neoplasms typically express CD10 , EMA , cytokeratin / CK
• uterine smooth muscle tumors express smooth muscle actin, desmin and h-caldesmon

 Pattern 4: sheetlike proliferations of large, round undifferentiated cells

• Includes undifferentiated malignancies such as high grade endometrial adenocarcinoma , MMMT , undifferentiated sarcomas, extension of cervical primary, metastatic carcinoma , melanoma , leukemia and lymphoma
• metastasis of lobular carcinoma of breast looks deceptively bland

 Pattern 5: extensive necrosis, inflammation and disintegration

• Necrosis suggests malignancy ; also cervical stenosis , pyometra and xanthomatous endometritis
• Inflammatory cells common in post-partum endometrium ; also bacterial infection
• Disintegration associated with menstruation , hyperplasia ; may mimic carcinoma due to stromal collapse

 Pattern 6: scanty samples that raise question of sampling adequacy

• May be due to atrophy or obstructing lesion that shields endometrium from sampling

See also

 uterine anomalies
 endometrium