Indian Journal of Dermatology
: 2013  |  Volume : 58  |  Issue : 1  |  Page : 84-

An asymptomatic papule on forearm

Vijay Adhe, Atul Dongre 
 Department of Dermatology, Seth GS Medical College & KEM Hospital, Parel, Mumbai, India

Correspondence Address:
Vijay Adhe
Department of Dermatology, Seth GS Medical College & KEM Hospital, Parel, Mumbai

How to cite this article:
Adhe V, Dongre A. An asymptomatic papule on forearm.Indian J Dermatol 2013;58:84-84

How to cite this URL:
Adhe V, Dongre A. An asymptomatic papule on forearm. Indian J Dermatol [serial online] 2013 [cited 2022 Jun 26 ];58:84-84
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Full Text

A 35-year-old male presented with an asymptomatic skin coloured raised lesion on right forearm for past 3 months. The lesion increased gradually in size over 3 months. Patient complained of pain in lesion on trivial trauma.

Cutaneous examination showed single, skin coloured, sessile, soft to firm and smooth surfaced papule of size about 0.5 × 0.5 cm on extensor surface of right forearm [Figure 1]. Tenderness could be elicited on palpation. Rest of the physical examination was normal.{Figure 1}

An excision biopsy of the lesion was done. Histopathology showed a solid-cystic tumor islands in the dermis without any connection to epidermis [Figure 2]. This tumor mass consisted of two types of cells [Figure 3], dark cells having round nuclei and scant cytoplasm and pale cells with round nuclei and ample cytoplasm [Figure 4]. At places, duct-like structures were seen within the tumor island [Figure 4]. The stroma was vascular and showed eosinophilic hyaline material deposition. No cytologic atypia or mitotic figures were seen.{Figure 2}{Figure 3}{Figure 4}


What is your diagnosis?


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Dermal duct tumor

Review of literature

Dermal duct tumor (DDT) is a benign tumor of the intradermal portion of the eccrine sweat ducts and was first described by Winkelmann and McLeod in 1966 as a distinct tumor. [1]

It is now considered as a histopathological variant of poroma[2] where tumor islands are confined to dermis and no connection with the epidermis is seen.

Clinically, it has non-specific appearance and presents as flesh colored or reddish papules or plaques of size ranging from a few millimetres to 2 cm. It is commonly seen on the head and neck, but can also occur on the extremities and trunk. [1,3,4] Clinically, it may resemble a dermal nevus, achrocordon, sebaceous adenoma, dermatofibroma and other adenexal tumors and can be differentiated on histological examination. [1,3]

Microscopically, [5,6] DDT shows intradermal masses consisting of poroid and cuticular cells in varying proportion. Poroid cells form a dominant population. Poroid cells have round basophilic nucleus, scant cytoplasm and appears dark, while cuticular cells have large amount of cytoplasm and appears pale. The duct formation usually occurs in the areas of cuticular cells. Some tumors may show few clear cells, which have a vacuolar appearance of the cytoplasm, due to large amount of glycogen material. It has been suggested that the poroid cell, which forms the major population of poroma can differentiate into cuticular and clear cells. [5]

Four histopathological variants of poroma have been described viz hidroacanthoma simplex (HS) (intraepidermal poroma), poroma, DDT and poroid hidradenoma (PH). [5,6] Histologically, all these variants in common have poroid, cuticular and clear cells in varying proportions with some differences. HS is purely intraepidermal collection of the neoplastic cells. A poroma is connected to the epidermis and extends into the dermis, as cords and broad columns, while PH is present in the dermis and has a solid-cystic appearance. Occurrence of more than one variant in a single lesion has been reported. [5]

The ductal lining of apocrine and eccrine ducts are indistinguishable from each other. Earlier, poroma was considered to be of eccrine origin and designated as eccrine poroma, but currently, due to evidence of sebaceous and follicular differentiation in some cases, it is believed to have both eccrine and apocrine origin. [7]

Histochemistry of the tumor demonstrates staining for phosphorylase, periodic acid-Schiff (PAS), adenosine triphosphatase, succinic dehydrogenase, cytochrome oxidase, and keratin. [3,5]

Simple surgical excision is recommended and recurrence is rare, following complete removal. [8]

The Winners of this Quiz are:

1. Shenoy M.V., Bangalore

2. Rameshwar M. Gutte, Mumbai


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3Hu CH, Marques AS, Winkelmann RK. Dermal duct tumor: A histochemical and electron microscopic study. Arch Dermatol 1978;114:1659-64.
4Faure M, Colomb D. Dermal duct tumor. J Cutan Pathol 1979;6:317-22.
5Kakinuma H, Miyamoto R, Iwasawa U, Baba S, Suzuki H. Three subtypes of poroid neoplasia in a single lesion: Eccrine poroma, hidroacanthoma simplex, and dermal duct tumor. Histologic, histochemical, and ultrastructural findings. Am J Dermatopathol 1994;16:66-72.
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8Apisarnthanarax P, Mullins JF. Dermal duct tumor. Arch Dermatol 1975;111:1171-3.