The pituitary gland as a factor in acromegaly and giantism: (1) the pitu itary body is still functional; (2) dis turbances of its metabolism are the prin cipal factors in both acromegaly and giantism, the difference between the re sults being simply due to the stage of individual development at which the dis turbance of the function begins; (3) the nature of the overgrowth in both these diseases is primarily on the order of a pure functional hypertrophy, later, how ever, losing some of the definiteness of its impulse and either producing immature tissue of a mixed type or resulting in simple exudation, with either cyst-formation or complete break ing down of the tissue-mass; (4) it seems probable, although upon this head the evidence is still uncertain, that some part is played by this body in "dwarf ism," rickets, and the dwarf forms of cretinism; (5) a reflex disturbance of its function may possibly underlie the dys trophy accompanying pharyngeal ade noids; (6) it would appear to he a sort of "growth-centre," or propo•tion-regu lator of the entire appendicular skeleton. Woods Hutchinson (N. Y. Med. Jour., July 2S, 1900).
The pituitary body is sometimes en larged from the size of a pigeon's egg to that of a hen's egg; it dilates the pitui tary fossa and clinoid processes, and is lodged in a considerable depression in the base of the brain. • Case in a woman, 35 years old, in whom symptoms of confirmed acrome galy had been present for three years. In May, 1893, there were visual disturb ances, and double optic neuritis was found to be present. In July, 1595, there were noted: complete blindness of the right eye, continuous headache, and pain in the limbs; the patient became somno lent and died in a comatose condition.
Autopsy showed the thymus to be abnormally voluminous and the thyroid gland normal. Some signs of adhesive meningitis were present at the vertex. The pituitary body was enlarged, soft ened, and vascular. The dura mater of the sena Turcica had disappeared, and the bone had been worn away in that region. The hypertrophy of the pitui tary body had compressed the two optic tracts and the chiasm, the right optic tract being partly destroyed and the left optic tract completely so. No other lesion was found. The pituitary body showed. microscopically, the appearance of a gliosarcoma. Roxburgh and A. Collis (Brit. Med. Jour., July 11, 'S9).
Case of acromegaly with post-mortem, at which the thymus was found replaced by a mass of fibrous fat and lymphoid tissue. The thyroid was enlarged sym metrically and filled with small cysts.
The gland-substance was normal under the microscope, but there was increase in the interstitial tissue. Pituitary body was enlarged and a portion of it pre sented consistence and microscopical ap pearance of an adenoid tumor. Pearce Bailey (Phila. Med. Jour., Apr. 30, '9S).
Cases have been reported, however, in which, although typical symptoms of the disease were present, no disease of the pituitary body could be detected.
Case with numerous cystic cavities in the brain, but with a normal pituitary body. Waldo (Brit. Med. Jour., Mar. 22, '90).
Case in a man, aged 74 years, in whom there was no tumor of the hypophysis, but endarteritis with atrophy and sclero sis of the thyroid body. Bonardi (Ri forma Medica, Aug. 24, '93).
Again, hypertrophy of the pituitary gland may not give rise to the manifes tations of the disease.
in which hypertrophy- of the pituitary gland had caused no phenome non of acromegaly. Packard (Amer. Jour. Med. Sciences, June, '92).
The pressure of the growths of the pituitary body on the optic tracts gives rise to the ocular disturbances enumer ated.
Case in which the pituitary body, which was the size of a walnut, was very soft and vascular. The mass had so pressed upon both optic tracts and the chiasm as to cause total disappearance of the left tract and partial destruction of the right. On the left side of the mass there was a blood-clot the size of a large pea. Roxburgh and Collis (Brit. Med. Jour., July 11, '96).
The hypophysis cerebri generally lies wholly or partly in front of, not behind, the chiasm, and its anterior part is so much nearer the optic nerves than its posterior part is to the chiasm (on ac count of the nerves, chiasm, and tracts slanting upward posteriorly) that with a uniform enlargement of the gland the nerves in front of the chiasm would almost always be pressed upon sooner than the chiasin itself. Zander (Deutsche med. Woch., vol. iii, p. 13, '97).
The nervous symptoms sometimes observed may also find in the pressure upon the surrounding cerebral tissues one of their causes.
Case of acromegaly of many years' standing in a man, aged 54, who, in the last three years, had developed Jackso nian epilepsy limited to the right upper extremity mid right side of the face. Hypertrophy of the pituitary gland con stitutes a cerebral tumor capable of exciting from a distance the cortical psychomotor centres. Raymond and Souques (Centralb. f. Nerv., No. S2, '96).
The viscera may take part in the hypertrophic process. The liver fre quently shows fatty degeneration.