An analysis of skin appendageal tumors: 10 year study

Introduction: Skin appendageal tumors are wide spectrum of disorders that differentiate towards one or more adnexal structures. Objective: To determine the prevalence of skin appengeal tumours. Materials and methods: This is a record based cross sectional study from the Department of pathology, Dr SMCSI Medical College between 1 st January 2004 to 1 st November 2014 who were diagnosed with skin tumours by histopathology and these cases were reviewed classified and analysed according to the patient's age, gender, and localization. Results: 166 cases were studied during this study period, males 68 and females 98. Mean age of presentation in this study was 34 years. Tumours with follicular differentiation constituted the maximum, 81 cases (48.8%), followed by eccrine differentiation constituting 22 cases (13.25%): tumours with apocrine differentiation 21cases (12.66%) and sebaceous differentiation 9 cases (5.4%). One case each of sebaceous adenoma and sebaceous carcinoma were the only malignant tumours. Conclusion: Skin adnexal tumours are relatively uncommon and the incidence of benign skin adnexal tumours are more common compared to the malignant ones.


Introduction
Skin appendageal tumours of the skin are really complex and have confusing nomenclature. Different types show marked variation in histological appearance and there is significant morphological overlap between the different types [1]. Even though most of the adnexal tumors are benign lesions, malignant variety also occur.
There are many inherited syndromes in which cutaneous adnexal tumors are a feature, and failure to recognize these associations may have serious implications [1]. Most of the benign present as a symptomatic papules or nodules and often troublesome to diagnose clinically however anatomic location, number and distribution of lesions provide important clue [2]. Few clinicopathological studies are available on adnexal tumours. The clinical history is essential for diagnosing skin appendageal tumours on biopsy [3].
Appendageal tumors are clinically non-descript, flesh colored, solitary or multiple papules or nodule. Some of them found to have penchant for certain parts of body like eccrine poroma which is most common is lower limb, but can occur in other parts also [4,5]. No known provoking conjucture is evident in the vast majority of appendgael tumours. There are some cases in which the reason is an autosomal dominant mutation in a tumour suppressor gene [6,7]. Adnexal tumours arising from the skin are usually missed clinically and often confirmed by histopathology [7,8]. They are however confirmed by histopathology, and immuno histochemistry may help in confirming the diagnosis. This study is done to determine the prevalence of skin appendageal tumours

Materials and Methods
Place and type of study: The present study includes the cases from 1st January 2004 to 1st November 2014. The study was done in the Department of pathology from Dr SMCSI Medical College. This is a record based cross sectional study.

Sampling method, collection and inclusion criteria:
The clinic pathological data was taken from the medical record department in Dr SMCSI Medical College for the given period. The cases which are included were

Original Research Article
Pathology Update: Tropical Journal of Pathology & Microbiology Available online at: www.pathologyreview.in 266 | P a g e diagnosed with skin tumours by histopathology and these cases were reviewed classified and analyzed according to the patient's age, gender, and localization and from which department the specimen was received.

Results
166 cases were studied during this study period. Among them, males were 68 (41%) and females were 98 (58%). Mean age of presentation in this study was 34 years.
The features of benign tumors are symmetrical, vertically orientated with V-shape with uniform collection of epithelial cells, dense fibrotic stromal reactions and absence of necrosis, atypia, and mitosis. Whereas the malign tumours show asymmetry, horizontal orientation of tumor, irregular arrangement of cells with infiltration, necrosis, atypia, mitosis, and diminished sclerotic stroma. Therefore, it is very important to examine the slide under scanner view to evaluate the configuration of adnexal tumours to differentiate benign and malignant ones. In this study we have used these criteria [14,18,19,20]. Males were 68 (41%) and females were 98 (58%  [15], El Ochi et al [16] also observed the same mean age. But Sharmaet al [14] got 40-60 years and Nair [17] got 10 -20 years. In our study tumours with follicular differentiation constituted the maximum, 81 cases (48.8%), followed by eccrine differentiation constituting 22 cases (13.25%) : tumours with apocrine differentiation 21 cases (12.66%) and sebaceous differentiation 9 cases (5.4%). Similar observation were seenin study of Kaur et al [12] and El Ochi et al [16] while Sharma et al [14] Nair [ 17], Vaishnav et al [21], Reddy et al [22] Gayathri et al [23] and Pujani et al [24] found sweat gland differentiation to be most common followed by follicular and seb-aceous differentiation. Pilomatricoma constituted the commonest tumour in benign nature. Similar observation was found in Rajalekshmi et al [15], El Ochi et al [16] and Kaur et al [12].  [13] and Nair [17] found syringoma as most common one. We got an interesting case of a man presented with a lower extremity swelling and was diagnosed as giant ectopic Hidradenoma papilliferum. It usually occurs in women in the perineal and perianal region [1,25,26]. In males, the most common site is perianal region. It is usually a few millimeters in size but in our case it was measuring 5.5 x 4.4 cm. Vang R also reported an ectopic hidradenoma pappileferum in a male in the lower extremity. In contradiction toanogenital hidradenoma papilliferum, nearly one half of the patients with ectopic hidradenoma papilliferum are men [27].

Conclusion
Skin appendageal tumoursare relatively uncommon. Clinical diagnosis of appendageal tumors is immensely troublesome because most of the tumors have similar clinical presentation and most of their symptoms are non specific. Benign tumours are more common compared to the malignant ones and malignancy is often hard to diagnose clinically. Histopathological examination becomes essential in diagnosis and it is the gold standard in the diagnosis of skin appendageal tumours.

What is new in this study?
A case of giant ectopic hidradenoma papilliferum was diagnosed in lower extremity. Ectopic sites of hidradenoma papilliferum are usually eyelid, nasal area, and breast. In lower extremity it has been the second case reported so far.
Funding: Nil, Conflict of interest: None initiated Permission from IRB: Yes