Indian ft. Pediat. 40: 246, 1973

ENDOCRINE GLANDS IN ANENCEPHALY* SAMIR C. MITRA AND G. VENKATARAMAN

Pondicherry H u m a n aneneephalic monsters are

not rare. Ballantyne (1904) estimated the incidence to be one in 1460 births. It is well known that in anencephaly the whole or a major part of the brain undergoes degeneration in early foetal life leading to a deficiency of the cranial vault. This intimate relationship between the proper growth of brain and that of its bony coverings has been effectively demonstrated by Fowler and Watterson

(1953). Apart from this, anencephaly is also associated with defects in many of the endocrine glands, of which particular mention is to be made of hypophysis, suprarenals, thyroid, thymus and gonads. Early workers in the field believed that hypotrophy of the supra- renals was the causative factor for anence- phaly. Subsequent workers have amply substantiated the contention that endo- crine abnormalities are not the cause but the effect of anencephaly. Penrose (1957) noted that geographical location influenced the incidence of anencephaly. Hamilton, Boyd and Mossman (1962) thought that this may be due not to climatic differences but to ethnic

differences. This has prompted the authors to

study whether differences in geogra- phical location alter the findings in the endocrine glands of anencephalics.

Mater ia l and Methods In order to study the endocrine

glands of human anencephalic foetuses

born in South India which is in the *From the Department of Anatomy, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondichery--6. Received on March 2, 1973.

torrid zone and has a population ethni- cally different from that in European countries, ten anencephalic foetuses of different sexes and different degrees of anencephaly conceived and born in South India of South Indian parents have been studied. All the endocrine and exo-endocrine glands of these foetuses were dissected out, weighed and studied histologically. Glands taken from ten normal foetuses of both sexes, also born in South India and of nearly the same intrauterine ages as the anencephalics, were studied in a similar way to serve as controls.

Both sets of specimens were studied histologically and hyperplasia, hypo- plasia or absence of parts were noted. A convenient weight parameter-- the organ index--has been utilized. The organ index is calculated by multiplying the weight of an organ by 100 and dividing the product by the body weight. In the case of suprarenals and gonads the combined weight of organs of both sides was taken into account for calculating the organ index. The body weight in the case of anencephalics was referred

to as estimated body weight and calcu- lated by adding ten per cent to their actual body weight, because brain index, on an average, is 11 in normal foetuses (Table 1). This compensates for the absence of brain in anencephalics.

Observat ions The various organ indices in 10

normal foetuses are shown in Table 1 and the indices and histological findings of anencephalic foetuses in Tables 2 and 3 respectively.

MITRA AND VENKATAP, AMAN~ENDOCRINE GLANDS I~ A~s ~7

~

o

0 0 0 0 ~ 0 c~ d c~ o c; o d o o c;

c~ c~ d c~ o ~ o c~ c5 c~

o ~

0,..~

.I

~ 0 ~

o d d c~ c~ o o o d d

d o o d 0 d c~ d o c~

~:~ ~ ~ ' ~ ' C~. ~ ~ ~ ~

.-g

0 ~

MITRA AND VENKATARA~fAN--ENDOCRINE GLANDS IN ~NENCIEPFIALY ~

~3

.m ~

o

N Z ~ ~ Z Z

cO 0

0 o~

r~

O O

~ ~, ~- ~- ~- ~ ~ o

QJ

O

~cc~ o Z

~ 0 I~IDIAN a.rou~NAL OP P~rATRIC~ Voz.. 40, No, 306

As endocrine, pancreas and

parathyroids did not show any variation from controls, either in weight or in histological appearance, these have not been included in any of the tables.

Hypophyses in anencephalic foetuses consist only of adenohypophysis without any trace of nemohypophysis. The weights of hypophyses in them are infinitesmaL Suprarena~ cornices on both sides in the anencephalic foetuses consist

only of adult cortex without any trace of foetal cortex beneath it unlike in normal foetuses. The weights of suprarenals in anencephalic foetuses were much less.

In anencephalic foetuses the thyroid exhibited hyperplasia (evidenced by colloid accumulation in distended at,hi) and increased weight in three, hypoplasia (evidenced by shrunkecj acini) in two and decreased weight in the same. The thymus in anencephalic foetuses showed hyperplasia (evidenced

hy large cortical areas packed with thymocytes) and increased weight in three, hypoplasia (evidenced by large medullary areas thinly populated with thymocytes but with large Hassall's corpuscles) and decreased weight in two.

The ovaries in anencephalic foetuses we;e hyperpIa~t~c (evidenced by the presence of innumerable ovarian follicles) in four with an increase in weight, None of the ovaries showed hypopla~ia or considerable decrease in weight, The testes in anencephalic foetuses showed hyperplasia of endocrine components

(evidenced by the presence of coasider- able intercellular substance) in one only with a considerable increase in weight, In all the others, the weight and histo- logical appearance were normal.

Discussion Most of the ~tudies on anencepha-

lies have been undertaken in Western countries which are in the temperate zone and have a population ethnically different from that in South India. Bansal et ah (1965) studied five anence-

phalic foetuses in India but they did not go into details of the weights and histo- ~ogi~aI appearances of the e~d~crine glands of these,

Zander (1890) made a detailed study of the measurements and weights of organs from forty-two European

anencephalics. Among others who worked in the field were Covell (1927), Angevine (1938) and Ch'in (1938). The latter worked on Chinese foetuses, and the

other two on American ones. As reported so far, most human

aneneephatie monsters have a very small pituitary with an absence of neurohy- pophysis, small suprarenals with absence of the foetal cortex, hyperplastic thyroid and thymus and hopoplastic gonads. The

findings in our study conform to the above except in the case of gonads which were not found to be hypoplastic. In the majority of c~ses the ovaries were

hyperplastic and the testes normal. This

variation may be related to climatic or ethnic influences

SuzQmary

Geographic and ethnic differences influence the incidence of anencephaly. This study was undertaken to assess the influence of such differences on the endocrine defects associated with anence-

phaly. All endocrine and exo-endocrine glands of t en h u m a n anencephalie monsters, conceived aad born of South

MIrRA AND VENKATARAMAN--ENDOGRINE GLANDS IN ANg.N~EPHALY 251

I n d i a n parents in South I n d i a , and

control specimens were subjected to

m i c r o a n a t o m i c a l e x a m i n a t i o n . The

gonads were not found to be hypoplast ic

or reduced in weight even in a single

case. I t has been suggested that this

d i sc repancy in g o n a d a l f indings may be

due to c l imat ic or e thn ic differences.

We are thankful to Prof. K Krishnaswamy and Prof. Indra Bhargava for allowing us to study foetuses in their respective departments.

References

Angevlne, D.M. (1938). Pathologic anatomy of hypophysis and adrenals in anence- phaly. Arch. Path. 26, 507.

Ballantyne,J.W. (1904). Manual of Antenatal Pathology and Hygiene Vol. 2. The Embryo. William Green & Sons, Edinburgh.

Bansal, P.C., Vare, A.M. and Indurkar,

G.M. (1965). Anencephalie monsters. Indian 07. Pediat. 32, 197.

Ch'in, K.Y. (1938). The endocrine glands of anencephalic foetuses: A quantitative and morphological study of 15 cases. Chinese Med. 07. Supp. 2, 63.

Covell, W.P. (1927). A quantitative study of the hypophysis of the human anencephalic foetus. Amer. 07. Path. y, 17.

Fowler, I. and W~tterson, R.L. (1953). The role of the neural tube in development of the axial skeleton of the chick. Anat. Ree. 117, 555.

Hamilton, W.J., Boyd, J.D. and Mossman, H.W. (1962). Human Embryology. W. Heifer & Sons Ltd., Cambridge. p. 147.

Penrose, L.S. (1957). Genetics of anence- phaly. 07. Ment. Def. Res. 1, 4.

Zander, R. (1890). Uber functionelle und genetische Beziehungen der Nebennieren zu anderen Organen, specielle zum Grosshirn. Beitr. Path. Anat. 7, 439.