Endometrioid carcinoma, with papillary features of intermediate grade (grade II)
Histopathology:
- Striking areas of papillary, micropapillary, glandular and tubular pattern
- Areas of low grade as well as areas of high grade nuclear atypia along with foci of loss of polarity are seen
- high grade areas show distinct nucleoli and moderate nuclear atypia
- Hobnail features are not seen, rather smooth lining of papilla
- Foci of squamous differentiation is also seen.
- Areas of necrosis and occasional mitotic figures are seen.
- Non-squamous solid area is less than 5%, but considering the significant nuclear atypia, best fitted diagnosis is Endometrial endometrioid carcinoma FIGO Grade 2.
Points of Pathoclinics:
- Always consider serous papillary carcinoma in the differentials. Absence of prominent pleomorphism and high mitotic activity in present case rules out its possibility. Note that occasionally serous carcinoma lacks marked cytologic atypia and increased nuclear/cytoplasmic ratio. Stain with p53, p16, and Ki-67 are helpful in differentiation.
- Presence of tumor necrosis is suggestive of aggressive behaviour
- Endometrioid carcinoma, with papillary features of intermediate grade has higher possibility of lympho-vascular invasion and lymph node metastasis
- Undifferentiated component and tumor infiltrating lymphocytes raise the possibility of Lynch syndrome associated endometrioid carcinoma.
Reference:
Gatius S, Matias-Guiu X. Practical issues in the diagnosis of serous carcinoma of the endometrium. Mod Pathol. 2016 Jan;29 Suppl 1:S45-58. doi: 10.1038/modpathol.2015.141. PMID: 26715173.