Ovary tumor
Mucinous tumors
Mural nodules in mucinous cystic neoplasms

Senior Author: Kruti P. Maniar, M.D.
Editorial Board Member: Carlos Parra-Herran, M.D.
Editor-in-Chief: Debra Zynger, M.D.
Brandon Umphress, M.D.
Kruti P. Maniar, M.D.

Topic Completed: 8 January 2019

Revised: 28 June 2019

Copyright: (c) 2003-2019, PathologyOutlines.com, Inc.

PubMed Search: Ovarian mural nodules

Related Topics: Sarcoma-like, Sarcomatous, Anaplastic carcinoma foci

Brandon Umphress, M.D.
Kruti P. Maniar, M.D.
Page views in 2018: 777
Page views in 2019 to date: 1,249
Cite this page: Umphress B, Maniar KP. Mural nodules in mucinous cystic neoplasms. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/ovarytumormuralnodules.html. Accessed September 22nd, 2019.
Definition / general
  • Grossly circumscribed nodules, most associated with primary ovarian mucinous neoplasms (less frequently other ovarian tumor types)
  • May be microscopically invasive but still separate / distinct from the associated mucinous tumor (Int J Gynecol Pathol 1994;13:62)
Essential features
  • May be reactive (sarcoma-like), benign neoplastic (leiomyomatous) or malignant (anaplastic carcinoma, sarcoma, carcinosarcoma)
  • Associated mucinous tumor may be benign, borderline or malignant
  • Can present a diagnostic challenge as the discrimination between truly malignant versus reactive mural nodules can be difficult
Terminology
  • General term: ovarian mucinous neoplasm with mural nodule
  • Various classification schema used (Int J Gynecol Pathol 1994;13:62, Cancer 1979;44:1332, Am J Surg Pathol 2008;32:383):
    • Reactive (sarcoma-like mural nodules)
      • Pleomorphic and epulis-like
      • Pleomorphic and spindle celled
      • Giant cell histiocytic
    • Benign neoplastic
    • Malignant neoplastic
      • Anaplastic carcinoma: rhabdoid, spindled or pleomorphic
      • Sarcoma
      • Carcinosarcoma
ICD coding
Epidemiology
Sites
  • Ovary (almost always unilateral)
Pathophysiology / etiology
  • Unclear histogenesis; however, may evolve through divergent differentiation of mucinous neoplasm or through a collision phenomenon (Int J Gynecol Pathol 2015;34:19)
  • Sarcoma-like mural nodules: likely common histogenesis for different subtypes, favored to be reactive and of histiocytic origin (Cancer 1979;44:1332, Am J Surg Pathol 2002;26:1467)
  • Malignant mural nodules clonally related to accompanying mucinous tumor and may represent dedifferentiation (Am J Surg Pathol 2017;41:1261)
  • Targeted next generation sequencing has shown a clonal relationship between carcinomatous mural nodules and the ovarian mucinous tumor, indicating a dedifferentiation process (Am J Surg Pathol 2017;41:1261)
Clinical features
Radiology images

Images hosted on other servers:

Mural anaplastic carcinoma

Mural leiomyoma

Prognostic factors
Case reports
Treatment
  • Appropriate treatment depends on nature of mural nodule (benign / reactive versus malignant) as well as type of associated mucinous tumor and stage at presentation
  • Tumors with sarcoma-like nodules can be followed after oophorectomy
  • Staging surgery can be considered in malignant mural nodules, as well as systemic treatment (particularly in patients with extra-ovarian tumor spread)
  • Reported cases have been variably treated (Cancer 1979;44:1332, Am J Surg Pathol 2002;26:1467, Am J Surg Pathol 2008;32:383)
    • Surgical treatment: unilateral salpingo-oophorectomy, bilateral salpingo-oophorectomy or bilateral salpingo-oophorectomy with hysterectomy
    • Subset of patients also underwent omentectomy, appendectomy or lymphadenectomy
    • Subset of patients treated with adjuvant chemotherapy, especially in cases of malignant nodules
Gross description
Gross images

Images hosted on other servers:

Mural leiomyoma

Sarcoma-like mural nodule

Anaplastic carcinoma mural nodule

Clear cell mural nodule

Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Kruti P. Maniar, M.D.

Mural carcinosarcoma

Stromal invasion

Atypical spindled and epithelial cells

CK7

Vimentin


Mural neuroendocrine carcinoma

Stromal invasion

Marked atypia

Synaptophysin



Contributed by Jian-Jun Wei, M.D.

Mural anaplastic carcinoma

Marked atypia

Vascular / stromal invasion

Metastasis


Mural carcinosarcoma

Stromal invasion

Malignant cells



Images hosted on other servers:

Rhabdomyoblastic

Sarcomatoid anaplastic

Virtual slides

Images hosted on other servers:

Anaplastic carcinoma

Positive stains
Negative stains
Molecular / cytogenetics description
  • Recent next generation sequencing study found identical KRAS mutations in paired mucinous tumors and carcinomatous mural nodules (Am J Surg Pathol 2017;41:1261, Int J Gynecol Pathol 2015;34:19)
    • Identical CDH1 and p53 mutations may also be seen in both components
    • Unpaired p53 and PTEN mutations detected in 2 mural nodules
  • One case of different KRAS mutations in sarcomatous mural nodule and associated mucinous tumor - suggests different clones of same tumor (Int J Gynecol Pathol 2014;33:186)
  • Overall findings support neoplastic nature of carcinomatous mural nodules and clonal relationship with better differentiated mucinous tumor; acquisition of additional mutations within the mucinous neoplasm may result in transformation to anaplastic morphology (Am J Surg Pathol 2017;41:1261)
  • Further larger molecular studies still needed to clearly elucidate the mechanisms and molecular alterations underlying the different types of mural nodules
Differential diagnosis
Board review question #1
Which of the following features favors diagnosis as a true sarcomatous mural nodule?

  1. Monotonous spindle cells with infiltration into stroma
  2. Positivity for CD68
  3. Positivity for pankeratin AE1 / AE3
  4. Presence of extravasated red blood cells and blood lakes
  5. Scattered osteoclast-like multinucleated giant cells
Board review answer #1
A. Monotonous spindle cells with infiltration into stroma

Comment Here
Board review question #2
60 year old patient had a 30 cm mucinous ovarian tumor removed. Gross exam demonstrated a 5 cm mural nodule. Based on the histologic image of the mural nodule (right) and the overlying mucinous tumor (left), which of the following is most likely true regarding tumor behavior?



  1. Absence of vascular invasion indicates that the tumor is benign
  2. Presence of cytologic atypia within the mural nodule indicates that it is malignant
  3. Presence of a fibrous layer between the nodule and the mucinous tumor indicates that the mural nodule is benign
  4. Presence of infiltrative tumor nests between the nodule and the mucinous tumor indicates that the mural nodule is malignant
  5. Tumor behavior will be driven by the mucinous tumor, which appears benign
Board review answer #2
D. Presence of infiltrative tumor nests between the nodule and the mucinous tumor indicates that the mural nodule is malignant

All mural nodules are characterized by the presence of a fibrous stromal layer between the nodule and the mucinous tumor. However, tumor invasion into this stroma is indicative of malignancy. Vascular invasion may also be seen in malignant mural nodules but is not required for diagnosis as such. Cytologic atypia may be seen in both malignant mural nodules and benign sarcoma-like mural nodules. A malignant mural nodule can be associated with poor prognosis regardless of the benignity of the associated mucinous tumor.

Comment Here
Back to top