Jotirnal of Cutaneous Pathology 1975: 2: 225-231

Trichoepithelioma and Pigmented Nevus. A Combined Malformation HOMAYOON R A M U A R I

AND

AMIU

H.

MEMREGAN

Dcpiirtment of Dermatology and Syphilology, Wayne State University School of Medicine, and Detroit General Hospital, Detroit, U.S.A. The occasional occurrences of combined hamartomas composed of nevus cell nevi and adnexal tumors are not chance happenings. Pigmented nevi are malformations consisting of nevus cells together with various connective tissue and epithelial components. The proliferation of these components results in the combined malformations, whose occurrence, we believe, is moie supporting evidence for the idea that pigmented nevi may have other components besides nevus cells. (Received for publication July 25, 1975)

Combinations of pigmented nevi and various forms of cutaneous adnexal hamartomas have been reported before (Mehregan & Staricco 1962, Mehtegan & Coskey 1972, Sigal & Saunders 1967, Foilman 1969, Mishima 1973, Halkin 1932, Schellander et al. 1974). This association has been considered a ehanee occtirrence (Sigal & Saunders 1967); a remarkable and an unexplained entity (Schellander et al. 1974); and a reason to assume that nevus cells may take their origin from sweatforming cells (Follman 1969). We are reporting seven instances in which nevus cell nevi occurred in combination with adnexal hamartomas. The significance of this association is discussed.

All lesions had manifested a recent change in size or appearance. Cases V and VI had developed a verrucous surface. In case II the lesion exhibited a central raised white area which clinically appeared similar to a milial cyst. All lesions had been present for months to years before any change had been noted. The age of the patients t anged from 11 to 66 years. All the lesions were located on the head. B. Histopathology Paraffin-embedded tissue sections were stained with hematoxylin-eosin; van Gieson's; acid orcein-giemsa; Gomori's retictiliim stain; and by a combination of aleian blue-periodic acid Schiff technique.

Material and Methods

Results

A. Cases Seveti cases taken from the files of our dermatopathology laboratory were studied. The clinical data are summarized in Table 1.

The histopathological features of the lesions in all cases studied were found to be similar. The lesions were elevated, domeshaped growths. The overlying epidermis

226

RAHBAKl AND MEHREGAN

Table 1. Clinical data on seven cases of combined malformations Case no.

Age in yrs.

Sex and race*

Duration

Appearance

Clinical diagnosis

Location of the lesion

I

26

F

Many years

Smooth surfaced nodule

Intraderma! nevus

Left temple

H

11

F

Years

Tan papule with raised white area

Pigmontcd nevus witb milial cyst

Righl check

HI

45

F

Years

"Dermal nevus"

Irritated dermal nevus

Right forehead

IV

66

F

5-10 years

Firm nevus

Dermal nevus

Cheek

27

M

Many years

Smooth surfaced nevus with a small verrucous lesion arising on tbe side

Intradermal nevus with ?verruca vtilgaris '.'basal cell epithelioma '.'seborrheic wart

Nose

VI

47

M

Months

"Reddened softened area with whitish calcifie area"

VH

20

F

Years

"Nevus"

Posterior ear

Dermal nevus

Left cheek

* All the subjects were white.

in one ease showed hyperkeratosis and mild acanthosis. In other cases the epidermal changes were not signifieant. Tbe growth appeated to displace the dermis and form a well-defined nodular mass below the epidermis. This tumor nodule was composed of two distinetive but intimately mixed eellular eomponents (Fig. 1). The first component, the nevus cells, lormed nests of various sizes and intermingled with the second component — the basaloid cells (Fig. 2). The basaloid cells formed small solid nests or thin branching strands. Tbe nests atid the strands of basaloid cells were seattered throughout the entire growth, mixed in with the nests of the nevus cells all embedded in a well-organized fibrovascular stroma. In several areas the nevus eell nests connected with the strands of

basaloid cells (Fig. 3). A few sections also showed nests of nevus cells at the dertnoepidermal junction. Seattered throughout some of the lesions were small keratin cysts in between or within the strands of basaloid cells. Some of these cysts showed eentral foci of calcification surrounded by whorls of keratinous material (Fig. 4). The cellular components of the growth were embedded it! a stroma made up of newly formed capillary blood vessels and connective tisstie fibers. Thin strands of eollagen and elastie fibers were present about the intermingled nests of nevus cells and strands of basaloid eells. The clastic and collagen fibers of the original dermis, present around the growth, were much coarser and evidently different from the newly formed fibers (Fig. 5). There were incteased numbers of capillary atid

TRICHOEPITHELIOMA AND PIGMENTED NEVUS

227

Fig. 1- Basaloid cells and nevus cells are intimately mixed. Acid orcein-giemsa, X 120.

Fig. 2. Higher magnification showing intermixture of the two components. Long arrow: nevus cells; short arrow: epithelial componenl. Acid orcein-giemsa, X 250.

228

RAHHARI AND MEHREGAN

'••:'^r'l:r--mM

Fig. 3. Notice the solid masses and branching strands of basaloid cells in between the nevus cells. H & E , X 120.

Fig. 4. Keratin cysts with foci of calcification (arrow.s) connected with the strands of basaloid cells. Acid orcein-gietnsa, X 200.

TRICHOEPITHELIOMA AND PIGMENTED NEVUS

229

Fig. 5. The thinner and finer newly-formed connective tissue fibers of the malformation (left) with the thicker and coarser fibers of the original dermis (right). Van Gieson. X 250.

Fig. 6. Abundant reticulum fibers enveloping and intermingling with the elements of the malformation. Gomori's retieulum stain, x 120.

RAHBARI AND MEHREGAN

230

lymphatic vessels, together with an appreciable number of mast eells in the matrix. Abundant retieulum fibers enveloped and were intermingled with the eellular element of the malformation, delineating the entire growth from the surrounding dermis (Fig. 6). The matrix of the lesion eontained alcian blue reaetive material. There was no evidence of inflammatory eell reaction in the stroma of the growth or irt the dermis surrounding the lesion. Discussion It is an accepted sequence of evetits that nevus eell nests develop at the dermoepidermal junetion, are soon surrounded by a fine network of retieulum fibers, and eventually become separated Irom the epidermis. The separated nevus eell nest in the dermis is engulfed by retieulum and collagen fibers and often by a network of elastic fibers. The presenee of prominent elastie fibers in eotijunetion with nevus eell nevi has been well doeumented (Mehregan & Stariceo 1962). In addition to this stroma, pigmented nevi often show an inerease in the tiumber of eapillary blood vessels and lymphatic spaees. There are often several forms of epithelial changes assoeiated with these eonnective tissue proliferations. The epidermis may show marked verrucous hyperplasia. The pilosebaceous struetures may be increased in number or occasionally be deficient. An increase in the number of pilosebaeeous struetures in conjunction with pigmented nevi is well known under the term "nevus pigmentosus et pilosus''. An abnormality of the hair follicles ill pigmented nevi oeeurs eommonly in the fortn of triehostasis spinulosa. Development of abortive hair follicles in pigmented nevi of the sole has been suggested in two eases (Mehregan & Coskey 1972). Follictilar cysts may form within or benealh the nevi which may break down giving rise

to the troublesome clinical condition eaused by ehronie inflammation, foreign body granuloma atid dermal fibrosis. Caleifieation and bone formation may occur as a sequela to the inflammation. Other adnexal struetures may also take part in the development of nevtis cell nevi. Follman (1969) showed the appearanee of nevus cell nests in conjunction with the eeerine sweat glands. Mishima (1973) very clearly demonstrated a elose relationship between nevus eell nests and eeerine sweat ducts under the title of eecrine-eentered nevus. Hal kin (1932) attempted to show the eombination of nevus eells and basal cell epitheliomas. Perhaps with the exception of his third case, we agree with Sehellander et al. (1974) that the eases presented by Halkin (1932) were probably pigmented basal eell epitheliomas rather than eombinations of basal cell epitheliomas and pigmented nevi. Sigal & Saunders (1967) presented two eases with the eombination of basal cell epithelioma and nevus eell nevi. Their first case fits our coneept of a combined malformation. Nevus eells are intermingled, with strands of basaloid eells and are embedded in a fibrotic stroma forming a unitary malformation. Sehellander et al. (1974) presented the most interesting examples. Their first three eases were almost identieal with ours in showing a eombination of nevus eell nevi together with strands of basaloid cells and small keratin cysts forming trichoepithelioma-like structures. We do not consider the occurrenee of these tumors as aecidental combined malformations but as supporting evidence for the idea that the nevus eell nevi are often eomplex neoplasms consisting of nevus cells together with the new formation of connective tissue and various types of epithelial elements. These latter constituents of the nevus cell nevi may proliferate and produce malformations ranging from verrueous epi-

TRICHOEPITHELIOMA AND PIGMENTED NEVUS dermal hyperplasia, stasis spinulosa, and epithelioma or basal junctioti with nevus

follieular cyst, trichoin extreme eases trichocell epithelioma in eotieell nevi.

Acknowledgments This study was supported in part by the Detroit Genetal Hospital Research Corporation. References Follman, E. (1969) Le probleme de l'origine de naevi cpitheliaux h la lumicre de naevus cellulaire sudoripare. Dcrttiatoloiiica 138, 251-262. Halkin, M. (1932) Les epitheliomas eutanes developpcs sur naevi pigmentaires. Bttlletin de I'Acadetnie rovale de tttedecitte dc Belgique 12, 447-457. Mehregan, A. H. & Starieeo, R. G. (1962) Elastic fibers in pigmented nevi. Jottrnal of Investigative Dertttatology 38, 271-276.

231

Mehregan, A. H. & Coskey, R. J. (1972) Pigmented nevi of sole. A report of two eases with histologic evidence of hair follicle formation. Arehives of Dertnatology 106, 886887. Mishima, Y. (1973) Eccrine-centered nevus. Archives of Deritiatology 107, 59-61. Pinkus, H. & Mehiegan, A. H. (1969) A Gttide to Dcrtitato/tistopathology, pp. 373. New York: Appleton-Century-Crofts, Inc. Schellander, F., Marks, R. & Wilson-Jones, E. (1974) Basal cell hamartoma and cellular naevus: an unusual combined malformation. British Jourttal of Dertnatology 9, 413—419. Sigal, C. & Saunders, T. S. (1967) Basal cell epithelioma and nevus pigmentosus, their simultaneous occurrence. Archives of Dertnatology 96, 520-523. Address: H. Rahbari, M.D. Pittktts Dertttatopathology Laboratoty 415 South Monroe Street P.O. Box 360 Monroe, Miehigatt 48161, U.S.A.

Trichoepithelioma and pigmented nevus. A combined malformation.

The occasional occurrences of combined hamartomas composed of nevus cell nevi and adnexal tumors are not chance happenings. Pigmented nevi are malform...
5MB Sizes 0 Downloads 0 Views