British Joumal of Dermatology (1975) 92, 659.
Adnexal polyp of neonatal skin A.HIDANO AND T.KOBAYASHI Department of Dermatology, Tokyo Women's Medical College, and Section of Dermatology, Tokyo Metropolitan Police Hospital, Tokyo Accepted for publication 16 September 1974
SUMMARY
The adnexal polyp of neonatal skin is a small, usually solitary tumour of the skin occurring mostly on the areola of the nipple of the neonate. Our statistics reveal an incidence of 40",, in 3,257 newborn infants. Histologically it always contains hair follicles, eccrine glands and vestigial sebaceous glands, hence the term 'adnexal polyp of neonatal skin' is proposed. No similar report has been hitherto recorded.
The adnexal polyp of neonatal skin (APN) is an elastic, firm and polypoid tumour, about one mm in diameter or less. The surface is smooth, and the colour is normal or pink (Fig. i). It can easily be
FIGURE 1. Adnexal polyp on the left breast. Correspondence address: A. Hidano, Department of Dermatology, Tokyo Women's Medical College, Kawadacho, Shinjuku, Tokyo 162, Japan.
66o
A.Hidano and T.Kobayashi
removed by the fingertip to leave minute bleeding. This tumour becomes dry and brownish and falls off spontaneously within a few days after birth. We made a statistical observation of all newborn infants born in the Tokyo Metropolitan Police Hospital from November 1968 to October 1973, and found the APN in 129 (40".,) of 3,257 infants. The majority were Japanese, but we found the tumour in one black infant from Zaire. While most of the affected infants had only one tumour, ten had two tumours and one had three. This brought the total to 141 tumours. In some infants the tumours were observed symmetrically on both nipples. As shown in Table i, the site of predilection is the areola of the nipple. Apart from one tumour on TABLE I. Site of the adnexal polyp of neonatal skin Right Left Lower eyelid Check Preauricular region Scapular region AxUla
Arm Areola of the nipple Hypochondrium Scrotutii Labia majora Total
0
I
I
2
I
0
0
2
I 0
0 I
55
68
0
I
I 0
2 I
59
the sternal region and three perimanmiary tumours in which the side was not noted, seventy-eight were found on the left side and fifty-nine on the right side. Usually they were found several millimetres medial to the nipple. They seem to fall off within a week after birth, as they were not observed in infants older than one week. One 26-day-Qld infant was an exception. Histology
The microscopic findings of the APN are typical. The epidermis is usually normal. At times it is covered by a thin crust, and in several tumours a small portion of the entire epidermis was necrotic and accompanied by subepidermal blisters. The most characteristic finding is the presence of adnexal elements in the centre of the tumour. There arc hair follicles, vestigial sebaceous glands and well developed eccrine glands (Fig. 2). Several follicles were curved and, at times, open to the surface. Keratinization of the hair was also noted, but no hair growing onto the skin surface. There arc no epithelial strands budding from the follicles. The sebaceous gland is not always found, and when noted, it is poorly developed and attached to the follicular infundibulum (Fig. 3). There is no arrector pili. Although apocrinc glands are absent, eccrine glands are usually well developed, and connection with the intraepidermal eccrine duct can be observed. The dermis contains fairly numerous small vessels, but no inflammatory infiltrate. The PAS stain and alcian blue stain are negative. The perifollicular collagen is rather loose. All of the tumours contain adnexal structures except for those in which the epidermis seems to have dried out. These old tumours contain only one or a few keratinous cysts surrounded by a thin epithelial wall and the dermal collagen is more or less eosinophilic and dense.
Adnexal polyp of neonatal skin
FIGURE 2, In the centre of the lesion arc found several hair follicles and eccrine glands (low magnification).
FIGURE 3. Vestigial sebaceous glands (high magnitication).
661
662
A.Hidano and T.Kobayashi
Comment The characteristics of the APN are summarized as follows: (1) It is a small, usually solitary tumour of the skin observed exclusively in the newborn infant. (2) The majority of the tumours are found on the areola of the nipple. (3) Within a few days the tumour falls ofl spontaneously. (4) Microscopically, hair follicles, vestigial sebaceous glands and eccrine glands are noted in the centre of the tumour. No similar tumour has been recorded in the literature. In newborn infants, accessory auricles and supernumerary breasts are not infrequently observed, but they We different from the APN both clinically and histologically. In the classification of tumours of hair follicle origin, Lever (1967) described the pigmentary hair naevus as an organic hamartoma, and the trichofolliculoma as an organoid hamartoma. Pinkus & Mehregan (1969) considered hair naevus, hair follicle naevus and trichofolliculoma as the best organized tumour of the pilosebaceous complex. For Duperrat & Mascaro (1965), naevus pilaire, trichofolliculoma and dermatosis papulosa nigra are 'hamartome parfait' of follicular origin. Apart from the presence of eccrine glands and the lack of epidermal hyperplasia, the APN is histologically quite similar to dermatosis papulosa nigra which contains immature hair follicles showing little tendency to sebaceous differentiation and occasional keratinous cysts. The degree of differentiation of the APN is about the same as organoid hamartomata. However in neither tumour nor naevus, as cited above, has the coexistence of eccrine glands been reported. On the other hand, in the eccrine naevus there is no pilosebaceous apparatus mixed in the tumour. Naevus syringosebaceus and naevus syringopilosebaceus in Nikolowski's paper (1958) show the coexistence of apocrine and sebaceous or pilosebaceous hamartomata, but in these tumours the apocrine and pilosebaceous elements grow side by side, not mixing as in the APN. Therefore, the APN is considered a unique hamartoma of syringo-pilo-sebaceous origin. The reason why the tumour falls off spontaneously remains unsolved. In tumours obtained from 4- or 5-day-old infants, the epidermis seems to be dried, but neither necrosis nor thrombosis could be observed in tbe corium. The adnexal components have regressed and only keratinous cysts are occasionally found in the centre of the tumour. We hesitate to call a naevus or hamartoma a tumour when it falls off spontaneously within a few days of life. For this reason, the term adnexal polyp of neonatal skin is proposed. REFERENCES DUPERRAT, B. & MASCARO, J . M . (1965) Essai de classification des tumeurs cuian^cs issues du follicule pilaire Aiinales de dermaiologie el de syphiligraphic, 92, 241.
LEVER, W . F . (1967) Hisioparbology of ihe skin, 4lh edn., p. 535. Lippincott, Philadelphia. MASCARO, J.M. (1963) Dermatosis papulosa nigra de Castcllani, aper^ hiscologique. BuUeiiti de la Soditi fraiifaise de dermatologie ei de syphitigraphie, 70, 535. NiKOLOWSKi, W. C195H) Tricho-Adenom. Archiv flir klinische und experimemelle Dermaiologie, 207, 34. PINKUS, H . & MEHRFGAN, A , H . (i96g) A Gitide to Dermaro-histaparhohgy, p. 441. Applcton-Ccntury-Crofts,
New York.
Adnexal polyp of neonatal skin A.HIDANO AND T.KOBAYASHI Department of Dermatology, Tokyo Women's Medical College, and Section of Dermatology, Tokyo Metropolitan Police Hospital, Tokyo Accepted for publication 16 September 1974
SUMMARY
The adnexal polyp of neonatal skin is a small, usually solitary tumour of the skin occurring mostly on the areola of the nipple of the neonate. Our statistics reveal an incidence of 40",, in 3,257 newborn infants. Histologically it always contains hair follicles, eccrine glands and vestigial sebaceous glands, hence the term 'adnexal polyp of neonatal skin' is proposed. No similar report has been hitherto recorded.
The adnexal polyp of neonatal skin (APN) is an elastic, firm and polypoid tumour, about one mm in diameter or less. The surface is smooth, and the colour is normal or pink (Fig. i). It can easily be
FIGURE 1. Adnexal polyp on the left breast. Correspondence address: A. Hidano, Department of Dermatology, Tokyo Women's Medical College, Kawadacho, Shinjuku, Tokyo 162, Japan.
66o
A.Hidano and T.Kobayashi
removed by the fingertip to leave minute bleeding. This tumour becomes dry and brownish and falls off spontaneously within a few days after birth. We made a statistical observation of all newborn infants born in the Tokyo Metropolitan Police Hospital from November 1968 to October 1973, and found the APN in 129 (40".,) of 3,257 infants. The majority were Japanese, but we found the tumour in one black infant from Zaire. While most of the affected infants had only one tumour, ten had two tumours and one had three. This brought the total to 141 tumours. In some infants the tumours were observed symmetrically on both nipples. As shown in Table i, the site of predilection is the areola of the nipple. Apart from one tumour on TABLE I. Site of the adnexal polyp of neonatal skin Right Left Lower eyelid Check Preauricular region Scapular region AxUla
Arm Areola of the nipple Hypochondrium Scrotutii Labia majora Total
0
I
I
2
I
0
0
2
I 0
0 I
55
68
0
I
I 0
2 I
59
the sternal region and three perimanmiary tumours in which the side was not noted, seventy-eight were found on the left side and fifty-nine on the right side. Usually they were found several millimetres medial to the nipple. They seem to fall off within a week after birth, as they were not observed in infants older than one week. One 26-day-Qld infant was an exception. Histology
The microscopic findings of the APN are typical. The epidermis is usually normal. At times it is covered by a thin crust, and in several tumours a small portion of the entire epidermis was necrotic and accompanied by subepidermal blisters. The most characteristic finding is the presence of adnexal elements in the centre of the tumour. There arc hair follicles, vestigial sebaceous glands and well developed eccrine glands (Fig. 2). Several follicles were curved and, at times, open to the surface. Keratinization of the hair was also noted, but no hair growing onto the skin surface. There arc no epithelial strands budding from the follicles. The sebaceous gland is not always found, and when noted, it is poorly developed and attached to the follicular infundibulum (Fig. 3). There is no arrector pili. Although apocrinc glands are absent, eccrine glands are usually well developed, and connection with the intraepidermal eccrine duct can be observed. The dermis contains fairly numerous small vessels, but no inflammatory infiltrate. The PAS stain and alcian blue stain are negative. The perifollicular collagen is rather loose. All of the tumours contain adnexal structures except for those in which the epidermis seems to have dried out. These old tumours contain only one or a few keratinous cysts surrounded by a thin epithelial wall and the dermal collagen is more or less eosinophilic and dense.
Adnexal polyp of neonatal skin
FIGURE 2, In the centre of the lesion arc found several hair follicles and eccrine glands (low magnification).
FIGURE 3. Vestigial sebaceous glands (high magnitication).
661
662
A.Hidano and T.Kobayashi
Comment The characteristics of the APN are summarized as follows: (1) It is a small, usually solitary tumour of the skin observed exclusively in the newborn infant. (2) The majority of the tumours are found on the areola of the nipple. (3) Within a few days the tumour falls ofl spontaneously. (4) Microscopically, hair follicles, vestigial sebaceous glands and eccrine glands are noted in the centre of the tumour. No similar tumour has been recorded in the literature. In newborn infants, accessory auricles and supernumerary breasts are not infrequently observed, but they We different from the APN both clinically and histologically. In the classification of tumours of hair follicle origin, Lever (1967) described the pigmentary hair naevus as an organic hamartoma, and the trichofolliculoma as an organoid hamartoma. Pinkus & Mehregan (1969) considered hair naevus, hair follicle naevus and trichofolliculoma as the best organized tumour of the pilosebaceous complex. For Duperrat & Mascaro (1965), naevus pilaire, trichofolliculoma and dermatosis papulosa nigra are 'hamartome parfait' of follicular origin. Apart from the presence of eccrine glands and the lack of epidermal hyperplasia, the APN is histologically quite similar to dermatosis papulosa nigra which contains immature hair follicles showing little tendency to sebaceous differentiation and occasional keratinous cysts. The degree of differentiation of the APN is about the same as organoid hamartomata. However in neither tumour nor naevus, as cited above, has the coexistence of eccrine glands been reported. On the other hand, in the eccrine naevus there is no pilosebaceous apparatus mixed in the tumour. Naevus syringosebaceus and naevus syringopilosebaceus in Nikolowski's paper (1958) show the coexistence of apocrine and sebaceous or pilosebaceous hamartomata, but in these tumours the apocrine and pilosebaceous elements grow side by side, not mixing as in the APN. Therefore, the APN is considered a unique hamartoma of syringo-pilo-sebaceous origin. The reason why the tumour falls off spontaneously remains unsolved. In tumours obtained from 4- or 5-day-old infants, the epidermis seems to be dried, but neither necrosis nor thrombosis could be observed in tbe corium. The adnexal components have regressed and only keratinous cysts are occasionally found in the centre of the tumour. We hesitate to call a naevus or hamartoma a tumour when it falls off spontaneously within a few days of life. For this reason, the term adnexal polyp of neonatal skin is proposed. REFERENCES DUPERRAT, B. & MASCARO, J . M . (1965) Essai de classification des tumeurs cuian^cs issues du follicule pilaire Aiinales de dermaiologie el de syphiligraphic, 92, 241.
LEVER, W . F . (1967) Hisioparbology of ihe skin, 4lh edn., p. 535. Lippincott, Philadelphia. MASCARO, J.M. (1963) Dermatosis papulosa nigra de Castcllani, aper^ hiscologique. BuUeiiti de la Soditi fraiifaise de dermatologie ei de syphitigraphie, 70, 535. NiKOLOWSKi, W. C195H) Tricho-Adenom. Archiv flir klinische und experimemelle Dermaiologie, 207, 34. PINKUS, H . & MEHRFGAN, A , H . (i96g) A Gitide to Dermaro-histaparhohgy, p. 441. Applcton-Ccntury-Crofts,
New York.
![[Adnexal skin tumors].](/assets/img/hold.png)
