Table of Contents
Definition / general | Prognostic factors | Microscopic (histologic) description | Microscopic (histologic) images | Molecular / cytogenetics description | Additional referencesCite this page: Ehdaivand S. Serous borderline tumor, micropapillary variant / noninvasive low grade serous carcinoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorserousmicropapillary.html. Accessed January 24th, 2021.
Definition / general
- Also called low grade serous carcinoma
- Behaves like low grade adenocarcinoma; appear to be derived from serous borderline tumor or adenofibroma
- Recurs as classic serous carcinoma
- 10 year survival is 70% versus ~100% for borderline tumors
- Invasive if destructive infiltrative growth; most are noninvasive
Prognostic factors
- Survival: dependent on stage and invasiveness of implants
- Stage I invasive or noninvasive has 100% disease free survival
- Stage II / III noninvasive or invasive with noninvasive implants has 80% disease free survival
- Stage II / III noninvasive with invasive implants has 55% 10 year survival
- Stage II / III invasive with invasive implants has 45% 10 year survival
Microscopic (histologic) description
- Filigree or cribriform pattern:
- Filigree pattern of small, uniform, elongated, stroma-poor or stroma-free papillae, at least five times as long as wide, arising directly in a nonhierarchical fashion from large fibrotic, edematous, or myxoid papillary stalks or from cyst walls
- Or a cribriform pattern of epithelial cells lining the stalks or cyst walls
- Or both; either or both patterns should be present on a confluent area at least 5 mm in greatest dimension on at least one slide; occasionally also have large macropapillae
- Noninvasive:
- Numerous delicate micropapillae (length > 5x width) with no / rare fibrovascular cores
- Radiates in "medusa" nonhierarchical branching pattern from thick fibrous stalks
- May be cribriform due to fusion
- Micropapillae are covered by cuboidal / columnar cells with minimal cytoplasm, variable psammoma bodies, no cilia, no / rare mitotic figures
- More recurrences but similar survival as serous borderline tumors (Am J Surg Pathol 2002;26:1129)
- Invasive:
- By definition, has destructive infiltrative growth
- Invasive areas may be > 3 mm or larger
- Stromal invasion is characterized by micropapillae and solid epithelial nests surrounded by a cleft or space and fibroblastic stroma
- May also have noninvasive component
- Variable psammoma bodies
- Rarely mitotic figures or atypical mitotic figures
- Macropapillary component may signify invasive disease (Am J Surg Pathol 2008;32:1800)
- Single cells or small clusters of cells appearing to be in spaces within nonreactive stroma are considered to NOT represent stromal invasion
Microscopic (histologic) images
Images hosted on other servers:
Large fibrovascular core entirely surrounded by long, slender micropapillae
Low grade nuclei
Ovary with non-invasive low grade serous carcinoma
Ovary with non-invasive component represented by an APST
Atypical proliferative (borderline) ovarian tumor
Mixture of macro and micropapillae
Molecular / cytogenetics description
- Chromosomal imbalances intermediate between serous borderline tumors and serous carcinomas (Hum Pathol 2002;33:47)
Additional references
