Tubular apocrine adenoma of the nose

ARTICLE

Auteur(s) : Tsuyoshi MITSUISHI tmitsu@nms.ac.jp, Seiji KAWANA

Department of Dermatology, Nippon Medical School, 1-1-5 Sendagi, Bunkyou-ku, Tokyo, 113-8603, Japan

A 61-year-old female was referred to our hospital for evaluation of a 6-month history of a solitary nodule on the nose. She did not have any notable medical history. On clinical examination, a hard, elastic, reddish nodule with a rough surface, 7 × 6 mm in diameter, was observed on the nose (figure 1A). The nodule was surgically removed under local anesthesia. Microscopic examination revealed many well-differentiated tubular structures, without connection to the follicular infundibulum, located in the dermis (figure 1B). The epidermis, with slight acanthosis, was almost intact and was not attached to the tumor masses. In the dermis, each irregularly shaped tubular structure was lined by 2 or more layers of cells, with the inner layer formed by cuboidal cells and outer layer formed by columnar cells. The cuboidal cells of the inner layer in the tubular structures showed decapitation secretion. The cuboidal and columnar cells showed absence of polymorphism, mitotic figures, and irregularly shaped nuclei. Cellular fragments and eosinophilic debris were observed in the tubular structure. The stroma of the tumor consisted of numerous fibroblasts (figure 1C). Immunohistochemical studies were performed on formalin-fixed, paraffin embedded tissue, using carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), cytokeratin (CK) 7, CAM 5.2, p63, smooth muscle antigen (SMA), Ki-67 (MIB1), androgen receptor, and gross cystic disease fluid protein (GCDFP)-15 antibodies. Among them, EMA, and CEA were predominantly stained in the inner surface of the tubular structure. SMA was slightly stained in the outer surface of the tubular structure. CK 7 and CAM 5.2 were stained in the numerous cells which consisted of the tubular structures (figure 1D). The GCDFP-15 showed focal diffuse cytoplasmic staining in most of the cells of the tubular structures (figure 1E). The proliferative index (MIB1) was approximately 5% (figure 1F). In contrast, the outer layer cells were positive for p63 (figure 1G). The androgen receptor was negative stained. These findings demonstrate characteristic clinicopathological features of tubular apocrine adenoma (TAA).

TAA is a rare sweat gland tumor that was first described by Landry and Winkelmann in 1972 [1]. The tumor presents as a well-defined nodule, mainly located on the scalp. Most lesions are less than 2 cm in diameter. Histopathologically, TAA is characterized by lobules of well differentiated tubular structures found in the dermis. The cells forming the tubular structures show apocrine differentiation with decapitation secretion [1]. As a differential diagnosis, TAA and syringocystadenoma papilliferum (SCAP) might represent a spectrum of single disease [2, 3]. Some authors have reported the coexistence of TAA and SCAP on the scalp [2, 3]. These two types of tumors show similar clinical, morphological, and immunohistochemical features and sometimes overlap. They occasionally appear in a sebaceous nevus [3]. Histopathologically, TAA is mostly located within the deep dermis and does not show cystically dilated invaginations or papillary projections, in comparison to SCAP [1-3]. Thus, our case was consistent with TAA. The tumor is usually located deep within the dermis of the scalp region. Rarely, TAA has been described in other locations such as the eyelid, chest, external auditory meatus, cheek, and vulva [4]. To our best knowledge, the present case represents the first description of TAA on the nose.

Deniake and Ackerman proposed that TTA in fact represents a malignant skin tumor [5]. Some authors have reported that aggressive clinical behavior may be observed [6]. Despite the lack of cellular atypia, TTA is considered as a locally aggressive malignancy [4, 6]. In our case, the cuboidal and columnar cells consisted of tubular structures showing an absence of polymorphism, mitotic figures, and atypical nuclei. Although surgical excision was performed for this tumor, careful follow-up should be recommended.

Disclosure

Financial support: none. Conflict of interest: none.

References

1 M Landry, R.K. Winkelmann An unusual tubular apocrine adenoma Arch Dermatol 1972; 105: 869-879.

2 CK Lee, KT Jang, Y.S. Cho Tubular apocrine adenoma with syringocystadenoma papilliferum arising from the external auditory canal J Laryngol Otol 2005; 119: 1004-1006.

3 BK Ahn, YK Park, Y.C. Kim A case of tubular apocrine adenoma with syringocystadenoma papilliferum arising in nevus sebaceus J Dermatol 2004; 31: 508-510.

4 DE Demellawy, D Daya, S. Alowami Vulvar apocrine tubular adenoma: an unusual location Int J Gynecol Pathol 2008; 27: 301-303.

5 Denianke K, Ackerman AB. Papillary eccrine adenoma is apocrine papillary carcinoma. Available at: www.derm101.com.

6 JM Burket, A.S. Zelickson Tubular apocrine adenoma with perineural invasion J Am Acad Dermatol 1984; 11: 639-642.