Archives of Sexual Behavior, Vol. 4, No. 6, 1975
Brief Report Sella Turcica in Male-to-Female Transsexuals P. O. Lundberg, M.D.,1 A. Sj6vall, M.D.,I and J. Wfilinder, M.D.2
Roentgenological examination o f the skull in 11 male-to-female transsexuals revealed considerable asymmetry (2.5-3 ram) o f the sellar floor in three cases. There was no asymmetry exceeding 1.5 mm in 103 male controls. Asymmetry o f the sella turcica suggests the presence o f an intrasellar pituitary tumor. This finding in three patients with transsexualism is o f interest in view o f reports o f endocrine disorders or hormonal secretion abnormalities in patients with atypical sexuality or gender identity problems. KEY WORDS: transsexualism; sella turcica; hormone; gender identity; pituitary.
INTRODUCTION Two male patients with transsexualism were referred to one of the authors (P. O. L.) because of the accidental funding of pronounced asymmetry of the sella turcica. It is known that an asymmetrical sella turcica may be the only roentgenological sign of an intrasellar pituitary tumor (R~dberg, 1963; McLachlan et al., 1970; Newton and Potts, 1971; Deck, 1973; Hardy, 1973; Vezina and Sutton, 1974). It is also known that transsexualism and other psychosexual disorders are sometimes seen in combination with tumors of the endocrine glands or with other endocrinological disorders (Bleuler, 1954; Sendrail and Gleizes, 1961; Routier et al., 1964, 1970). Thus it seemed justified to study the sella turcica in a larger number of patients with transsexualism and to compare it with that of nontranssexual persons.
1Departments of Neurology and Diagnostic Radiology, University Hospital, Uppsala, Sweden. 2Psychiatric Research Center, St. J6rgen's Hospital, Hisings Backa, Sweden. 657 Q 1 9 7 5 P l e n u m Publishing C o r p o r a t i o n , 2 2 7 West 1 7 t h S t r e e t , N e w Y o r k , N . Y . 1 0 0 1 1 . No part o f this p u b l i c a t i o n m a y be r e p r o d u c e d , stored in a retrieval s y s t e m , or t r a n s m i t t e d , in a n y f o r m or b y a n y means, e l e c t r o n i c , m e c h a n i c a l , p h o t o c o p y i n g , m i c r o f i l m i n g , r e c o r d i n g , or o t h e r w i s e , w i t h o u t w r i t t e n permission o f the publisher.
658
Lundberg, Sj~Jvall,and W~linder MATERIAL
The two original patients and a further nine males with transsexualism who had been referred to one of the authors (J. W.) were submitted to roentgenography of the skull. The diagnosis of transsexualism was used for a condition in which the subjects are convinced that they belong to the opposite sex and external sex characteristics are a source of disgust and torment. These people are driven to have the body, appearance, and social status of the opposite sex. Otherwise, our patients were all healthy males and only one of them had received any kind of hormonal treatment (estrogens) before the investigation. The age range at the time of the roentgenographic examination was 16-33 years and the mean age was 23.3 years. It has been shown (Bergstr6m et aI., 1973) that the volume and shape of the sella turcica are fairly constant in adult males of different ages. On the other hand, older females have a significantly larger sella turcica than younger females. For this reason, it did not seem appropriate to include females in the present investigation.
CONTROLS A total of 103 male patients aged 15-60 years who had undergone skull roentgenography because of suspected skull fracture or sinusitis served as controls. Nothing is known about the psychiatric or endocrine condition of these patients, but it seems reasonable to assume that they adequately represent the normal population since the indication for X-ray was an acute emergency situation. Whether the control group included any person with atypical sexuality is not known. Regarding the prevalence rate of transsexualism, it has been estimated to be at least one out of every 40,000 males and one out of every 100,000 females (W~linder, 1967). In a more recent investigation, Hoenig and Kenna (1974) arrived at similar figures. While homosexuality is more prevalent than transsexualism, it still seems unlikely that the control group includes sufficient persons with atypical sexuality to invalidate our results.
METHOD The volume of the sella turcica was determined according to di Chiro (1960), but with slight modifications as described in an earlier report (Bergstr6m et al., 1973). The degree of symmetry of the sellar floor was determined by measurement of the difference in height between the lateral borders of the sella and a line parallel to the sphenoidal plane in anteroposterior frontal projections.
Sella Turcica in Male-to-Female Transsexuals
659
All measurements were made with an accuracy of 0.5 mm. It has been shown (R~dberg, 1963) that neither the presence nor the degree of asymmetry can be ascertained in lateral projections alone.
RESULTS In the control group, there were no cases of asymmetry or central depres, sion of the sellar floor exceeding 1.5 mm. This is in agreement with the findings of McLachlan et al. (1970). The mean sellar volume was 623 mm 3 , range 220-1070 m m 3 (Fig. 1). Three of the transsexual patients had asymmetry of the sellar floor exceeding the findings in the control group, 2.5 mm in one case and 3 m m in two cases (Figs. 2 and 3). The mean sellar volume in the group of transsexual patients w a s 680 m m 3 . None of the patients had a central depression of the sellar floor exceeding 1 mm. The difference in volume between the two groups is not statistically significant. In none of the patients did the sellar volume exceed the limits set by the
__
m
j 3
#]I
m m
o,o
2
4 6
i
I I l
8 m
10
i
12 14 16
Fig. 1. Histogram of sellar volume measurements in mm a . Above line, the transsexual cases; below, the control cases; n denotes number of cases. Numbers within squares (2.5, 3, and 3, respectively) denote asymmetry of seUar floor in mm.
660
Lundberg, Sj~vall, and W~linder
Fig. 2. Lateral view o f the sella in one o f the transsexual patients with an asymmetrical sellar floor.
Fig. 3. Posteroantefior seUar view o f one o f the patients with an asymmetrical sellar floor. Arrows point at the asymmetrical floor.
Seila Turcica in Male-to-Female Transsexuals
661
control group. Two of the patients with asymmetrical sellar floors had volumes near the upper limit, 955 and 988 mm 3 , while the third patient had a volume of 675 mm 3 (Fig. 1).
DISCUSSION It has been shown that in about 40% of cases o f surgically verified pituitary adenomas asymmetry o f the pituitary fossa is found (T6nnis et al., 1957; Ross and Greitz, 1966) and that an overall enlargement of the sella is not always present. Intrasellar pituitary adenomas not large enough to cause an increase in sellar size but give asymmetry to the sellar floor are sometimes referred to as microadenomas. These tumors, verified by transsphenoidal surgery, are usually less than 10 mm in diameter and may be localized in different parts of the anterior pituitary. A correlation seems to exist between clinical symptomatology and anatomical localization (Hardy, 1973). An asymmetry o f the sellar floor may be an early sign o f a pituitary tumor, but it may also be found in nontumorous, progressive enlargements o f the sella turcica, the so-called empty sella syndrome (Kaufman et al., 1973). The finding o f sellar abnormalities in the present three cases is suggestive of a pituitary pathology. Of course, this observation must be interpreted with great caution. However, we consider it worth reporting since during recent years an increasing number o f publications have appeared describing endocrine disorders or hormonal secretion abnormalities in patients with atypical sexuality or gender identity problems (Erhardt and Money, 1967; Erhardt et al., 1968; Erhardt, 1969; Loraine et al., 1970; Kolodny et al., 1971; D6rner et al., 1972; Money, 1972a,b; Kolodny et al., 1972; Margolese and Janiger, 1973; Yalom, 1973).
REFERENCES BergstriSm, K., Lundberg, P. O., and Sj6vall, A. (1973). The volume of the sella turcica in patients with anorexia nervosa. Eur. Neurol. 9: 183-189. Bleuler, M. (1954). Endokrinologische Psychiatrie, G. Thieme Veflag, Stuttgart. Deck, M. D. F. (1973). Radiographic and radioisotopic techniques in diagnosis of pituitary tumors. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment of Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 71-85. di Chiro, G. (1960). The width (third dimension) of the sella turcica. Am. J. Roentgenol. 84: 26-37. D6rner, G., Rohde, W., and Krell, L. (1972). AusRisung eines positiven OstrogenfeedbackEffekt bei homo sexuellen Mgnnern. Endokrinologie 3:297-301. Erhardt, A. (1969). Zur Wirkung ftStaler Hormone auf Intelligenz und geschlechtsspezifisches Verhalten. Dissertation, DUsseldorf. Erhardt, A., and Money, J. (1967). Progestin-induced hermaphroditism: IQ and psychosexual identity in a study of ten girls. J. Sex. Res. 3: 83-100.
662
Lundberg, Sj~vall, and W~linder
Erhardt, A., Epstein, R., and Money, J. (1968). Fetal androgens and female gender identity in the early-treated adrenogenital syndrome. Johns Hopkins Med. J. 122: 160-167. Hardy, J. (1973). Transsphenoidal surgery ofhypersecreting pituitary tumors. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment o f Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 179-194. Hoenig, J., and Kenna, J. C. (1974). The prevalence of transsexualism in England and Wales. Brit. J. Psychiat. 124: 181-190. Kaufman, B., Pearson, O. H., and Chamberlin, W. B. (1973). Radiographic features of intrasellar masses and progressive asymmetrical non-tumorous enlargements of the sella turcica, the "empty" sella. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment o f Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 100-129. Kolodny, R. C., Masters, W. H., Hendryx, J., and Toro, G. (1971). Plasma testosteron and semen analysis in male homosexuals. New Engl. J. Meal. 185: 1170-1174. Kolodny, R. C., Jacobs, L. S., Masters, W. H., Toro, G., and Daughaday, W. H. (1972). Plasma gonadotrophins and prolactin in male homosexuals. Lancet ii: 18-20. Loraine, J. A., Ismail, A. A. A., Adamopoulos, D. A., and Dove, G. A. (1970). Endocrine function in male and female homosexuals. Brit. Med. J. 4: 406-408. Margolese, M. S., and Janiger, O. (1973). Androsterone/etiocholanolone ratios in male homosexuals. Brit. Med. J. 3i 207-210. McLachlan, M. S. F., Wright, A. D., and Doyle, F. H. (1970). Plain ffilm and tomographic assessment of the pituitary fossa in 140 acromegahc patients. Brit. J. Radiol. 43: 360-369. Money, J. (19'/2a). Phyletie and idiosyncratic determinants of gender identity. Dan. Med. Bull. 19: 259-262. Money, J. (1972b). Identification and complementation in the differentiation of gender identity. Dan. Med. Bull. 19: 265-268. Newton, T. H., and Potts, D. G., eds. (1971). Radiology of the SkullandBrain: The Skull, Vol. 1/Book 1, Mosby, St. Louis, Missouri, pp. 374-377. Radberg, C. (1963). Some aspects of the asymmetric enlargement of sella turcica. Acta Radiol. (Diagn.). 1: 152-163. Ross, R., and Greitz, T. (1966). Changes of the sella turcica in chromophobic adenomas and eosinophilic adenomas. Radiology 86: 892-899. Routier, G., Paget, M., Ernst, J., Langeron, P., Wiart, P., Duthoit, F., and Cousin, J. (1964). Tumeur f~minisante de la surr6nale et transsexualism. Ann. Endocrinol. 25: 680-685. Routier, G., Ernst, J., and Paget, M. (1970). Le transsexualisme: Valeur respective des d6terminants biologiques et psychiques. Sere. Hop. Paris 46: 947-952. Sendrail, M., and Gleizes, L. (1961). Le trans-sexualisme feminin et le probl~me de ses conditions psychiques ou hormonales. Rev. Fr. Endocrinol.-Clin. 2: 35-43. T6nnis, W., Friedmann, G., and Albrecht, H. (1957). Zur r6ntgenologischen Differentialdiagnose der Hypophysenadenome (Unter besonderer Berticksichtigung der prim~iren und sekund//ren Sellaver~inderungen). Fortsehr. Geb. ROntgenstrahlen 87: 677-686. Vezina, J. L., and Sutton, T. J. (1974). Prolactin-secreting pituitary microadenomas: Roentgenologic diagnosis. Am. J. Roentgenol. 120: 46-54. • W~linder, J. (1967). Transsexualism: A Study o f Forty-three Cases, Scandinavian University Books, AkademifiSrlaget, G~teborg. Yalom, I. D. (1973). Prenatal exposure to female hormones: Effect on psychosexual development in boys. Arch. Gen. Psychiat. 28: 554-561.
Brief Report Sella Turcica in Male-to-Female Transsexuals P. O. Lundberg, M.D.,1 A. Sj6vall, M.D.,I and J. Wfilinder, M.D.2
Roentgenological examination o f the skull in 11 male-to-female transsexuals revealed considerable asymmetry (2.5-3 ram) o f the sellar floor in three cases. There was no asymmetry exceeding 1.5 mm in 103 male controls. Asymmetry o f the sella turcica suggests the presence o f an intrasellar pituitary tumor. This finding in three patients with transsexualism is o f interest in view o f reports o f endocrine disorders or hormonal secretion abnormalities in patients with atypical sexuality or gender identity problems. KEY WORDS: transsexualism; sella turcica; hormone; gender identity; pituitary.
INTRODUCTION Two male patients with transsexualism were referred to one of the authors (P. O. L.) because of the accidental funding of pronounced asymmetry of the sella turcica. It is known that an asymmetrical sella turcica may be the only roentgenological sign of an intrasellar pituitary tumor (R~dberg, 1963; McLachlan et al., 1970; Newton and Potts, 1971; Deck, 1973; Hardy, 1973; Vezina and Sutton, 1974). It is also known that transsexualism and other psychosexual disorders are sometimes seen in combination with tumors of the endocrine glands or with other endocrinological disorders (Bleuler, 1954; Sendrail and Gleizes, 1961; Routier et al., 1964, 1970). Thus it seemed justified to study the sella turcica in a larger number of patients with transsexualism and to compare it with that of nontranssexual persons.
1Departments of Neurology and Diagnostic Radiology, University Hospital, Uppsala, Sweden. 2Psychiatric Research Center, St. J6rgen's Hospital, Hisings Backa, Sweden. 657 Q 1 9 7 5 P l e n u m Publishing C o r p o r a t i o n , 2 2 7 West 1 7 t h S t r e e t , N e w Y o r k , N . Y . 1 0 0 1 1 . No part o f this p u b l i c a t i o n m a y be r e p r o d u c e d , stored in a retrieval s y s t e m , or t r a n s m i t t e d , in a n y f o r m or b y a n y means, e l e c t r o n i c , m e c h a n i c a l , p h o t o c o p y i n g , m i c r o f i l m i n g , r e c o r d i n g , or o t h e r w i s e , w i t h o u t w r i t t e n permission o f the publisher.
658
Lundberg, Sj~Jvall,and W~linder MATERIAL
The two original patients and a further nine males with transsexualism who had been referred to one of the authors (J. W.) were submitted to roentgenography of the skull. The diagnosis of transsexualism was used for a condition in which the subjects are convinced that they belong to the opposite sex and external sex characteristics are a source of disgust and torment. These people are driven to have the body, appearance, and social status of the opposite sex. Otherwise, our patients were all healthy males and only one of them had received any kind of hormonal treatment (estrogens) before the investigation. The age range at the time of the roentgenographic examination was 16-33 years and the mean age was 23.3 years. It has been shown (Bergstr6m et aI., 1973) that the volume and shape of the sella turcica are fairly constant in adult males of different ages. On the other hand, older females have a significantly larger sella turcica than younger females. For this reason, it did not seem appropriate to include females in the present investigation.
CONTROLS A total of 103 male patients aged 15-60 years who had undergone skull roentgenography because of suspected skull fracture or sinusitis served as controls. Nothing is known about the psychiatric or endocrine condition of these patients, but it seems reasonable to assume that they adequately represent the normal population since the indication for X-ray was an acute emergency situation. Whether the control group included any person with atypical sexuality is not known. Regarding the prevalence rate of transsexualism, it has been estimated to be at least one out of every 40,000 males and one out of every 100,000 females (W~linder, 1967). In a more recent investigation, Hoenig and Kenna (1974) arrived at similar figures. While homosexuality is more prevalent than transsexualism, it still seems unlikely that the control group includes sufficient persons with atypical sexuality to invalidate our results.
METHOD The volume of the sella turcica was determined according to di Chiro (1960), but with slight modifications as described in an earlier report (Bergstr6m et al., 1973). The degree of symmetry of the sellar floor was determined by measurement of the difference in height between the lateral borders of the sella and a line parallel to the sphenoidal plane in anteroposterior frontal projections.
Sella Turcica in Male-to-Female Transsexuals
659
All measurements were made with an accuracy of 0.5 mm. It has been shown (R~dberg, 1963) that neither the presence nor the degree of asymmetry can be ascertained in lateral projections alone.
RESULTS In the control group, there were no cases of asymmetry or central depres, sion of the sellar floor exceeding 1.5 mm. This is in agreement with the findings of McLachlan et al. (1970). The mean sellar volume was 623 mm 3 , range 220-1070 m m 3 (Fig. 1). Three of the transsexual patients had asymmetry of the sellar floor exceeding the findings in the control group, 2.5 mm in one case and 3 m m in two cases (Figs. 2 and 3). The mean sellar volume in the group of transsexual patients w a s 680 m m 3 . None of the patients had a central depression of the sellar floor exceeding 1 mm. The difference in volume between the two groups is not statistically significant. In none of the patients did the sellar volume exceed the limits set by the
__
m
j 3
#]I
m m
o,o
2
4 6
i
I I l
8 m
10
i
12 14 16
Fig. 1. Histogram of sellar volume measurements in mm a . Above line, the transsexual cases; below, the control cases; n denotes number of cases. Numbers within squares (2.5, 3, and 3, respectively) denote asymmetry of seUar floor in mm.
660
Lundberg, Sj~vall, and W~linder
Fig. 2. Lateral view o f the sella in one o f the transsexual patients with an asymmetrical sellar floor.
Fig. 3. Posteroantefior seUar view o f one o f the patients with an asymmetrical sellar floor. Arrows point at the asymmetrical floor.
Seila Turcica in Male-to-Female Transsexuals
661
control group. Two of the patients with asymmetrical sellar floors had volumes near the upper limit, 955 and 988 mm 3 , while the third patient had a volume of 675 mm 3 (Fig. 1).
DISCUSSION It has been shown that in about 40% of cases o f surgically verified pituitary adenomas asymmetry o f the pituitary fossa is found (T6nnis et al., 1957; Ross and Greitz, 1966) and that an overall enlargement of the sella is not always present. Intrasellar pituitary adenomas not large enough to cause an increase in sellar size but give asymmetry to the sellar floor are sometimes referred to as microadenomas. These tumors, verified by transsphenoidal surgery, are usually less than 10 mm in diameter and may be localized in different parts of the anterior pituitary. A correlation seems to exist between clinical symptomatology and anatomical localization (Hardy, 1973). An asymmetry o f the sellar floor may be an early sign o f a pituitary tumor, but it may also be found in nontumorous, progressive enlargements o f the sella turcica, the so-called empty sella syndrome (Kaufman et al., 1973). The finding o f sellar abnormalities in the present three cases is suggestive of a pituitary pathology. Of course, this observation must be interpreted with great caution. However, we consider it worth reporting since during recent years an increasing number o f publications have appeared describing endocrine disorders or hormonal secretion abnormalities in patients with atypical sexuality or gender identity problems (Erhardt and Money, 1967; Erhardt et al., 1968; Erhardt, 1969; Loraine et al., 1970; Kolodny et al., 1971; D6rner et al., 1972; Money, 1972a,b; Kolodny et al., 1972; Margolese and Janiger, 1973; Yalom, 1973).
REFERENCES BergstriSm, K., Lundberg, P. O., and Sj6vall, A. (1973). The volume of the sella turcica in patients with anorexia nervosa. Eur. Neurol. 9: 183-189. Bleuler, M. (1954). Endokrinologische Psychiatrie, G. Thieme Veflag, Stuttgart. Deck, M. D. F. (1973). Radiographic and radioisotopic techniques in diagnosis of pituitary tumors. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment of Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 71-85. di Chiro, G. (1960). The width (third dimension) of the sella turcica. Am. J. Roentgenol. 84: 26-37. D6rner, G., Rohde, W., and Krell, L. (1972). AusRisung eines positiven OstrogenfeedbackEffekt bei homo sexuellen Mgnnern. Endokrinologie 3:297-301. Erhardt, A. (1969). Zur Wirkung ftStaler Hormone auf Intelligenz und geschlechtsspezifisches Verhalten. Dissertation, DUsseldorf. Erhardt, A., and Money, J. (1967). Progestin-induced hermaphroditism: IQ and psychosexual identity in a study of ten girls. J. Sex. Res. 3: 83-100.
662
Lundberg, Sj~vall, and W~linder
Erhardt, A., Epstein, R., and Money, J. (1968). Fetal androgens and female gender identity in the early-treated adrenogenital syndrome. Johns Hopkins Med. J. 122: 160-167. Hardy, J. (1973). Transsphenoidal surgery ofhypersecreting pituitary tumors. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment o f Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 179-194. Hoenig, J., and Kenna, J. C. (1974). The prevalence of transsexualism in England and Wales. Brit. J. Psychiat. 124: 181-190. Kaufman, B., Pearson, O. H., and Chamberlin, W. B. (1973). Radiographic features of intrasellar masses and progressive asymmetrical non-tumorous enlargements of the sella turcica, the "empty" sella. In Kohler, P. O., and Ross, G. T. (eds.), Diagnosis and Treatment o f Pituitary Tumors, Excerpta Medica, Amsterdam, pp. 100-129. Kolodny, R. C., Masters, W. H., Hendryx, J., and Toro, G. (1971). Plasma testosteron and semen analysis in male homosexuals. New Engl. J. Meal. 185: 1170-1174. Kolodny, R. C., Jacobs, L. S., Masters, W. H., Toro, G., and Daughaday, W. H. (1972). Plasma gonadotrophins and prolactin in male homosexuals. Lancet ii: 18-20. Loraine, J. A., Ismail, A. A. A., Adamopoulos, D. A., and Dove, G. A. (1970). Endocrine function in male and female homosexuals. Brit. Med. J. 4: 406-408. Margolese, M. S., and Janiger, O. (1973). Androsterone/etiocholanolone ratios in male homosexuals. Brit. Med. J. 3i 207-210. McLachlan, M. S. F., Wright, A. D., and Doyle, F. H. (1970). Plain ffilm and tomographic assessment of the pituitary fossa in 140 acromegahc patients. Brit. J. Radiol. 43: 360-369. Money, J. (19'/2a). Phyletie and idiosyncratic determinants of gender identity. Dan. Med. Bull. 19: 259-262. Money, J. (1972b). Identification and complementation in the differentiation of gender identity. Dan. Med. Bull. 19: 265-268. Newton, T. H., and Potts, D. G., eds. (1971). Radiology of the SkullandBrain: The Skull, Vol. 1/Book 1, Mosby, St. Louis, Missouri, pp. 374-377. Radberg, C. (1963). Some aspects of the asymmetric enlargement of sella turcica. Acta Radiol. (Diagn.). 1: 152-163. Ross, R., and Greitz, T. (1966). Changes of the sella turcica in chromophobic adenomas and eosinophilic adenomas. Radiology 86: 892-899. Routier, G., Paget, M., Ernst, J., Langeron, P., Wiart, P., Duthoit, F., and Cousin, J. (1964). Tumeur f~minisante de la surr6nale et transsexualism. Ann. Endocrinol. 25: 680-685. Routier, G., Ernst, J., and Paget, M. (1970). Le transsexualisme: Valeur respective des d6terminants biologiques et psychiques. Sere. Hop. Paris 46: 947-952. Sendrail, M., and Gleizes, L. (1961). Le trans-sexualisme feminin et le probl~me de ses conditions psychiques ou hormonales. Rev. Fr. Endocrinol.-Clin. 2: 35-43. T6nnis, W., Friedmann, G., and Albrecht, H. (1957). Zur r6ntgenologischen Differentialdiagnose der Hypophysenadenome (Unter besonderer Berticksichtigung der prim~iren und sekund//ren Sellaver~inderungen). Fortsehr. Geb. ROntgenstrahlen 87: 677-686. Vezina, J. L., and Sutton, T. J. (1974). Prolactin-secreting pituitary microadenomas: Roentgenologic diagnosis. Am. J. Roentgenol. 120: 46-54. • W~linder, J. (1967). Transsexualism: A Study o f Forty-three Cases, Scandinavian University Books, AkademifiSrlaget, G~teborg. Yalom, I. D. (1973). Prenatal exposure to female hormones: Effect on psychosexual development in boys. Arch. Gen. Psychiat. 28: 554-561.
