Detection of Fat Cells in Uterine Scars During Normal Pregnancy and with Placenta Accreta Spectrum

The aim was to investigate the presence of fat cells (adipocytes) using morphological methods in the uterus of women without signs of scarring, with well–off scars after cesarean section (CS), as well as in a group  of  patients  with  different  variants  of  atypical  placentation.

Material  and  methods.  A  retrospective histological and immunohistochemical study of the uterine wall material obtained during abdominal delivery in normal pregnancy without a previous CS in medical history (group 1, n=10), in normal pregnancy with a previous CS in anamnesis and the presence of a scar in the uterine wall (group 2, n=23) was performed, in pregnancy complicated  by  the  ingrowth  of placental  villi  (group  3,  n=22).

Results.  In  the  uteroplacental region,  the  fat component was found in all three groups. No adipocytes were found in group 1 (0%). In group 2, fields of fat cells of different sizes were found in 19 cases out of 23 studied (83%) and only in the scar zone: in serosa 40%, in the perivascular  zone 28%, among muscle bundles 15%. In the 3rd  group with the ingrowth of placental villi into the  scar zone, a “hernia” of the thinned uterine wall was detected in 68% of cases. The adipocytic component in this group was detected in 86% of cases (19 out of 22). Localization of adipocytes was observed in serosa (56%), in the perivascular zone (25%) and among muscle bundles (6%). No adipocytic component was found in the uterine wall outside the scar tissue.

Conclusion. An adipocytic component was identified, undoubtedly associated with traumatic damage to the uterus and the presence of a scar in the wall. What are the relationships between the presence of fat cells in the scar tissue and its predisposition to the pathology of ingrowth of villi is unknown and requires further research.

1. Milovanov AP, Nizyaeva NV, Fokina TV, Tikhonova NB, Kulikov IA, Shmakov RG. Clinical and morphological characteristics of the atypical placentation spectrum in the uterus. Arkhiv patologii. 2023 Jan 1;85(2):13–3. (In Russ.) doi: 10.17116/patol20238502113

2. Rogov KA, Tikhonova N.B., Boltovskaya MN, Milovanov AP. Morphological Aspects of the Disturbances of the Myometrial Repair After Cesarean Section. Kliničeskaâ i èksperimentalʹ naâ morfologiâ. 2018 Jan 1;(2(26). (In Russ.) doi: 10.31088/2226-5988-2018-26-2-48-54

3. Tikhonova NB, Milovanov AP, Aleksankina VV, Fokina TV, Boltovskaya MN, Aleksankin AP. The role of adipose tissue in the healing of rat uterine wall after a full-thickness surgical incision. Clinical and Experimental Morphology. 2021;10(4):72–80. (In Russ.) doi: 10.31088/CEM2021.10.4.72-80

4. Afrin S, El Sabah M, Ahmed M, Miyashita M, Reschke L, Borahay MA. Adipocyte coculture induces a pro-inflammatory, fibrotic, angiogenic, and proliferative microenvironment in uterine leiomyoma cells. Biochimica Et Biophysica Acta: Molecular Basis Of Disease. 2023 Jan 1;1869(1):166564–4. Doi 10.1016/j.bbadis.2022.166564

5. Gantov M, Pagnotta P, Lotufo C, Rindone G, Riera M, Calvo J, et al. Beige adipocytes contribute to breast cancer progression. Oncology Reports. 2020 Oct 27;45(1):317–28. doi: 10.3892/or.2020.7826

6. Hillock-Watling C, Gotlieb AI. The pathobiology of perivascular adipose tissue (PVAT), the fourth layer of the blood vessel wall. Cardiovascular Pathology. 2022 Nov 1;61:107459–9. doi: 10.1016/j.carpath.2022.107459

7. Khong TY. The pathology of placenta accreta, a worldwide epidemic. Journal of Clinical Pathology. 2008 Jul 19;61(12):1243–6. doi: 10.1136/jcp.2008.055202

8. Lofrumento DD, Di Nardo MA, De Falco M, Di Lieto A. Uterine Wound Healing: A Complex Process Mediated by Proteins and Peptides. Current Protein & Peptide Science. 2016 Dec 14;18(2):125–8.

9. Shook BA, Wasko RR, Mano O, Rutenberg-Schoenberg M, Rudolph MC, Zirak B, et al. Dermal Adipocyte Lipolysis and Myofibroblast Conversion Are Required for Efficient Skin Repair. Cell Stem Cell. 2020 Jun;26(6):880-895.e6. doi: 10.1016/j.stem.2020.03.013

10. Tikhonova N.B., Milovanov AP, Aleksankina VV, Fokina TV, Boltovskaya MN, Aleksankin AP, et al. Analysis of Healing of Rat Uterine Wall After Full-Thickness Surgical Incision. Bulletin of Experimental Biology and Medicine. 2021 Nov 17;172(1):100–4. doi: 10.1007/s10517-021-05340-y