A clinico-histopathological study of appendageal skin tumors, affecting head and neck region in patients attending the dermatology opd of a tertiary care centre in eastern India.

INTRODUCTION: Appendageal skin tumors (ATs) are those neoplasms that differentiate toward/arise from pilosebaceous apparatus, apocrine, or eccrine sweat glands. Pilosebaceous apparatus are concentrated in head-neck area; thus it is expected that ATs would account for a major fraction of skin tumors over this site. AIMS: This study aims at finding the clinico-histopathological correlation in cases ATs in head-neck region among attendees of dermatology OPD.
MATERIALS AND METHODS: Cross-sectional descriptive study, conducted over 1-year period. All clinically suspected cases of ATs were evaluated and subjected to histopathological examination. Confirmed cases of ATs were finally analyzed.
RESULTS: Among twenty eight thousand four hundred sixty six new patients attending OPD, 30 suspected cases of ATs underwent histopathological examination. Histopathology was confirmatory in only 23 (76.67%) cases. Out of 23, syringoma were found in 9 (39.13%), trichoepithelioma in 6 (26.08%), syringocystadenoma papilliferum in 4 (17.39%), sebaceous gland hyperplasia in 3 (13.04%), and vellous hair cyst in 1 (4.34 %). Females (65.21%) outnumbered males (34.78%) in our study population.
CONCLUSIONS: ATs of head-neck region constitute a meager population (0.08%) attending dermatology OPD, and were more common among young population. Often it is over-diagnosed clinically thus necessitating histological confirmation. Young females being cosmetically more conscious are more eager to seek advice for this condition.

Introduction

Appendageal tumors (ATs) are neoplasms which differentiate toward or arise from pilosebaceous apparatus, apocrine gland or eccrine sweat gland.[1] Head–neck region is unique because of its rich distribution of pilosebaceous apparatus, apocrine as well as eccrine sweat glands. It has also been previously documentedthat ATs predominate over head–neck area.[1] Clinical diagnosis of different entity is often difficult, as most of the ATs present as asymptomatic papules or nodules. Anatomic location, number and distribution of lesions provide important clue but histopathology is invaluable in confirmation of the diagnosis.[2]

Majority of these tumors are benign[34] and the malignant ones are usually irregularly shaped, solitary, rapidly growing plaques or nodules that have a tendency to ulcerate. Risk of malignant degeneration varies with individual lesions.[2] Local recurrence is well recorded but metastases is rare with the exception of the malignant eccrine and apocrine gland derived tumors and sebaceous carcinoma.[3]

The study aims at finding the relative attendance of patients with ATs in head–neck region among the attendees of dermatology OPD of a tertiary care centre of Eastern India along with clinico-histopathological correlation in those cases.

Materials and Methods

It was a cross-sectional, descriptive study, conducted over a period of 1 year from June 2007 to May 2008. Total numbers of patients attending dermatology OPD were recorded and clinically suspicious cases of ATs were evaluated. Histopathological examination was advised in all suspected cases and only those subjects consenting for histopathology were included for the study. Confirmed cases of AT were considered as the finally analyzable subjects.

Results

Twenty eight thousand four hundred sixty six new patients attended the OPD of which 37 (0.129%) were suspected to have appendageal tumors. Seven patients refused to give consent for biopsy. Thirty patients underwent histopathological examination among which the diagnoses of ATs were confirmed in 23 (76.67%) cases. In the remaining seven patients, histopathology revealed either milia or epidermal cyst or basal cell epithelioma.

The occurrence of appendageal tumor represented very small population of patients attending the dermatology OPD [Table 1] with the confirmed cases comprising 0.08% of total attendance. In our study, 76.66% of clinically suspicious cases were proved to be of appendageal origin. Syringoma constituted the bulk of the tumor (40%) followed by trichoepithelioma (26%), syringocystadenoma papilliferum (17%), sebaceous hyperplasia (13%), and vellus hair cyst (4%), respectively [Table 2].

Table 1

Comparison of profile of patients with appendageal tumor against the total OPD attendees

Table 2

Demographic profile of the patients with appendageal tumors in head and neck region

Mean presenting age of our study population was 29.19 ± 11.68 years (ranging from 9.5 to 55 years). Mean age of onset was 24.15 ± 8.44 years and the duration of complaints 6.40 ± 6.31 years. Age of onset was highest for syringoma (26.11 ± 8.16 years) and lowest for trichoepithelioma (16.91 ± 7.21 years); whereas age at presentation was found to be highest in syringocystadenoma papilliferum (39.50 ± 15.41 years) so also the duration before presentation (12.25 ± 8.95 years). Minimum presenting age was found in trichoepithelioma (22.41 ± 7.13 years) and duration before presentation was found to be lowest in syringoma (4.44 ± 4.21 years).

Regarding site of involvement, we found all cases of trichoepithelioma were concentrated around nose and surrounding area [Figure 1]. Periorbital area and cheeks were found to be the commonest site for syringoma. In one case of syringoma, lesions were also seen over the forearm along with involvement of cheek.

Figure 1

The bar diagram showing the site of occurrence of different appendageal tumors. (It is to be noted that there were patients with more than one site of affection.)

Similar patterns of involvement among family members were found in two out of nine subjects with syringoma. Solitary lesion was found in two out of six subjects with trichoepithelioma. Pre-existing nevus sebaceous was found in three out of four cases of syringocystadenoma papilliferum [Table 2].

Females outnumbered (65.21%) males (34.78%) in our study population with the sex ratio of about 1:2 (male: female); though the male:female ratio among the OPD attendees was almost 1.5:1 [Table 1].

Discussion

ATs are relatively rare and only 0.08% of patients attending the OPD were found to be suffering from ATs our study.ATs are classified into 4 types according to their differentiation toward apocrine gland, eccrine gland, sebaceous gland and hair follicle.[5] Importance of diagnosing ATs lies in the fact that in some instances the presence of ATs may lead to the recognition of a genetic syndrome, like Muir-Torre syndrome associated with sebaceous tumors, Cowden's syndrome with trichilemmomas, etc.[3]

It is currently believed that ATs are derived from cells that have the ability to differentiate toward any of the appendages. In many lesions, the differentiation is uniform and the tumor can be recognized and categorized based on its resemblance to a normal appendage or part of it. In other cases, the pluripotent cell may differentiate toward more than one type of appendage giving rise to a tumor that contains element of two or more appendage in varying degrees of maturation.[3] Various studieshad been done showing these combined characteristics of ATs.[67] In our study, though such combined nature was not detected.

The clinical appearance of appendageal tumor is mostly non-specific[1] and their diagnosis lie firmly in the realm of histopathologists. In our study, 23.3% (7 out of 30) of clinically suspected cases were proved to be non-AT after histopathological examination. Milia were mistaken as syringoma, basal cell epithelioma as desmoplastic trichoepithelioma and epidermal cyst as poroma. Hence, these entities should be kept in mind before making a diagnosis of ATs.

The long duration (6.40 ± 6.31 years) of the tumors seen in our study as well as their asymptomatic nature, in most cases, points toward benign nature of the tumors. In our study, histopathological features of malignancy was absent in all cases and supports the usual benign course of the ATs. Cases were seen most frequently in younger age group (25 ± 14.33 years), which is in concordance with other studies.[1-3]

In our study, syringoma [Figure 2a,b] constituted the bulk of the cases (40 %). We found two subjects (22.22%) with syringoma having positive family history supporting the text book data that syringoma does not always run in family.[2] Eruptive variety of syringoma is an uncommon entity which occurs over sites other than face,[2] and in our study we found the eruptive variety in only one subject. Affection of eyelids and cheeks were found to be an exclusive feature of syringoma.

Figure 2

(a) Syringoma in a 26-year-old female;(b) Histopathology of syringoma showing cords of epithelial cells resembling tadpole (H & E stain, 100×).

In our study, all cases of trichoepithelioma [Figure 3a,b] were distributed around nose suggesting that trichoepithelioma remains the primary differential diagnosis of ATs centered around nose. Trichoepithelioma was found to be solitary only in two cases (33%), which is contradictory to the previous study where solitary variety was found to be more common than multiple.[5]

Figure 3

(a) Multiple trichoepitheliomas over the nasolabial fold in 30-year-old male; (b) Histopathology of trichoepithelioma showing variably sized tumor masses with cribriform appearance and horn cyst (H & E stain, 100×)

Among four subjects of syringocystadenoma papilliferum [Figure 4a,b], three (75%) arose from nevus sebaceous and one developed (25%) de novo. This is quite expected because de novo variant of syringocystadenoma papilliferum is much less common.[2] Childhood presentations can occur in syringocystadenoma papilliferum but is reported to be very rare. In our study, none of the patients had affection since childhood. The long duration of the tumor before presentation (12.25 ± 8.95 years) can be explained by the fact that in our study population most cases were preceded by a pre-existing nevoid condition.

Figure 4

(a) Syringocystadenoma papilliferum over a pre-existing nevus-sebaceous; (b) Histopathology of syringocystadenoma papilliferum showing cystic invagination of surface epithelium with papillary folds (H & E stain, 100×)

Sebaceous hyperplasia [Figure 5a,b], a hyperplastic condition of sebaceous gland, was the fourth variant of appendageal tumor of our study. We found three subjects of this variety but none were found to be associated with Muir-Torre syndrome.

Figure 5

(a) Sebaceous hyperplasia in a 28-year-old male; (b) Histopathology of sebaceous hyperplasia large mature sebaceous lobules (H & E stain, 400×)

Vellus hair cyst [Figure 6a,b] usually occurs over mid chest and proximal upper extremities and axillae.[23] We found only one such case, where multiple dome shaped cysts were present over the forehead. The case was unique by the virtue of its site of occurrence.

Figure 6

(a) Multiple vellus hair cyst on the forehead of a 35-year-old male; (b) Histopathology of multiple vellus hair cyst showing cystic structure in the dermis with hair shafts and keratin material in the lumen (H & E stain, 50×).

To summarize, ATs of head–neck region is relatively uncommon and constitutes a meager population (0.08%) attending dermatology OPD. Though site of affection and clinical appearance can serve as vital clue at times, but not always clinically suspected cases conform to ATs. This highlights the need for histological confirmation. The higher attendance of females of any age group and younger male, with this condition may be explained by the fact that they are cosmetically more conscious. There is a dearth of studies regarding the clinico-pathological correlation of ATs over head–neck region in English literature published in index journals; hence, this study makes a modest attempt to fill up this lacuna.