Morphology and Histogenesis of Thymus as a Tool for Estimating Foetal Age: A Cross-sectional Study
Introduction: The thymus is located in the superior mediastinum and anterior part of the inferior mediastinum. It plays a crucial role in the development, differentiation, and clonal expansion of T lymphocytes. In forensic cases involving foetal death, accurate estimation of foetal age is essent...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
JCDR Research and Publications Private Limited
2023-09-01
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| Series: | Journal of Clinical and Diagnostic Research |
| Subjects: | |
| Online Access: | https://www.jcdr.net/articles/PDF/18443/66073_CE[Ra1]_F(SL)_QC(AN_OM)_PF1(RI_SS)_PFA(NC_OM)_PN(OM).pdf |
| Summary: | Introduction: The thymus is located in the superior mediastinum
and anterior part of the inferior mediastinum. It plays a crucial
role in the development, differentiation, and clonal expansion
of T lymphocytes. In forensic cases involving foetal death,
accurate estimation of foetal age is essential. When the foetus
is extensively damaged, other organs can be used to estimate
age. The thymus, being retrosternal and well-protected, is
easily accessible during dissection. Therefore, studying the
gross features and histogenesis of the thymus can be helpful in
estimating gestational age in cases of severely mutilated foetal
specimens.
Aim: To examine the morphological features and histogenesis
of the thymus in aborted and stillborn foetuses from normal
pregnancies.
Materials and Methods: A pilot study was conducted using a
cross-sectional design at the Department of Anatomy, BLDEDU’s
Shri BM Patil Medical College, Vijayapura, Karnataka, India,
from May 2016 to April 2018. The dimensions and histogenesis
of the thymus were studied in a total of 50 human foetal thymus
specimens, collected from normal pregnancies across different
gestational age groups ranging from 12 to 40 weeks. The
specimens were obtained from the Department of Pathology and
the Department of Obstetrics and Gynaecology. The dimensions
and weight of the thymus were recorded during autopsy. Slides
were prepared, stained with Haematoxylin and Eosin (H&E), and
examined under a compound microscope. The histogenesis of
the thymus was studied to observe its maturation.
Results: Foetal weight increased from 134.6±58.3 g at 12
weeks to 1942±598 g at 40 weeks. The weight of the thymus
ranged from 0.2 g at 12 weeks to 5.9 g at 40 weeks. Crown
rump length varied from 10.7 cm to 29.9 cm. The length of
the thymus measured between 0.5 cm and 3.3 cm, breadth
between 0.4 cm and 2.3 cm, and height between 0.2 cm and
0.9 cm from 12 to 40 weeks of gestation. Microscopic features
observed in the present study at different gestational ages
included a well-formed thick capsule at 17 weeks, lobulation
starting at 19 weeks, cortico-medullary differentiation beginning
at 17 weeks, appearance of epithelial cells around 19 weeks,
and initial appearance of Hassal’s corpuscles at 17 weeks, with
more numbers observed later on.
Conclusion: The thymus can be used in forensic investigations
to estimate the gestational age of mutilated foetuses. It exhibits
varying features at different gestational ages, which can aid in
thymectomy procedures. Additionally, these findings can be
considered during prenatal imaging studies. |
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| ISSN: | 2249-782X 0973-709X |