Pediatric Dermatology Vol. 22 No. 2 175–176, 2005 175 Address correspondence to Arun C. Inamadar, M.D., Professor & Head, Department of Dermatology, Venereology & Leprology, BLDEA’s SBMP Medical College, Hospital & Research Center, Bijapur – 586103, Karnataka, India, or e-mail: aruninamadar@rediffmail.com. Blackwell Publishing, Ltd. CLINICOPATHOLOGIC CONFERENCE Editors: Anne W. Lucky, M.D., and Julie S. Prendiville, M.B., M.R.C.P.I., F.R.C.P.C. Painful Nodules with Episodic Hyperhidrosis Arun C. Inamadar, M.D.,* Aparna Palit, M.D.,* V. V. Sampagavi, D.V.D.,* and B. R. Yelikar, M.D.† *Department of Dermatology, Venereology & Leprosy, and †Department of Pathology, BLDEA’s SBMP Medical College, Hospital & Research Center, Bijapur, Karnataka, India CASE REPORT An 11-year-old girl presented with three nodular lesions on the medial aspect of the right knee that have been present since early childhood. There was a gradual increase in the size of the lesions, associated with occa- sional pain. On handling, beads of clear fluid would appear over the lesions (Fig. 1). The nodules were closely set, dome-shaped, and about 2.5 × 2.5 cm in size. The overlying skin was smooth and hyperpigmented, with a bluish hue. The consistency of the nodules was firm, asso- ciated with tenderness and localized sweating following palpation. The local temperature was normal and no pul- sation or bruit was appreciated. A radiograph of the right knee joint was normal. An excision biopsy was performed and the histopatho- logic findings are demonstrated in Fig. 2. WHAT IS YOUR DIAGNOSIS? Diagnosis: Eccrine Angiomatous Hamartoma HISTOPATHOLOGIC FINDINGS The hematoxylin and eosin-stained tissue section showed an acanthotic epidermis. In the deeper part of the dermis were aggregates of mature eccrine sweat glands, intermingled with numerous thin walled blood vessels (Fig. 2). Adipose tissue and hyperplastic nerve bundles were seen adjacent to the previously mentioned structures. An Alcian blue stain did not reveal the presence of mucin. DISCUSSION Eccrine angiomatous hamartoma (EAH) is a very rare, benign tumor (1). The clinical features were first described by Lotzbeck in 1895 (2). The term EAH was coined by Hymen in 1968 (2). In addition to the mature and functional eccrine glandular and vascular proliferation, the lesion may contain lipomatous tissue, lymphatic structures, pilar structures, nerve bundles, or a myxomatous stroma consistent with its hamartomatous nature (3). The lesions of this entity can be present at birth or appear in early childhood (4). The onset in adulthood and the appearance of lesions following radiotherapy have also been reported (5). The most common site of involvement is any extremity. Bilateral symmetrical lesions or multiple nodules all over the body have been described (4). The most common morphology is a bluish or brown nodule or plaque, but EAH may present as a hypertrichotic or hyper- hidrotic patch (1). The lesions are associated with pain and tenderness. Characteristic beads of sweat appear at the periphery of the lesion following manipulation. However, these symptoms and signs are variable in occurrence. Histopathologic diagnosis is based on the presence of hyperplastic, normal, or dilated eccrine glands in close association with hyperplastic foci of capillaries, with vari- able occurrence of hair follicles, adipose tissue, mucin, or lymphatic structures (1). The lesion is well-demarcated, nonencapsulated, and situated deep in the dermis (5). A mucinous stroma surrounding the lesion (5) and epidermal proliferation (3) may be seen. Immunohistochemical studies are suggestive of apocrine differentiation of the hyperplastic secretory cells (2). Address correspondence to Arun C. Inamadar, M.D., Professor & Head, Department of Dermatology, Venereology & Leprology, BLDEA’s SBMP Medical College, Hospital & Research Center, Bijapur – 586103, Karnataka, India, or e-mail: aruninamadar@rediffmail.com.