A 61‐year‐old Japanese man had a gradually growing, red‐colored nodule in his umbilicus from 3 years ago. He had no symptoms such as hot flush, diarrhea or wheezing. Computed tomography detected a 3.0 cm × 3.0 cm enhanced nodule on the umbilical portion, inguinal and axillary lymph node swelling, and peritoneal nodules. Upper and lower gastrointestinal endoscopy and cystoscopy did not show any other tumor. We resected the umbilical nodule and subjected the inguinal lymph node and peritoneal nodule to biopsy. Histopathological findings indicated that the cutaneous lesion was composed of variously sized nests that included small, monomorphic, round to polygonal cells, mainly in the dermis to the peritoneum. Mitotic figures were scant. The inguinal lymph node and peritoneal nodule were positive for metastasis. Immunohistochemistry was diffusely positive for cytokeratin (CK)‐7, CD56, chromogranin A, synaptophysin, estrogen receptor‐α, progesterone receptor, GATA3 and carcinoembryonic antigen, and focally positive for mammaglobin and gross cystic disease fluid protein 15. The Ki‐67 labeling index was 1.5%. The patient was diagnosed with a case of low‐grade neuroendocrine carcinoma of the skin (LGNECS) occurring on the umbilicus. This case exhibited distant peritoneal metastasis, as well as inguinal and axillary lymph node metastases; however, the patient is alive without chemotherapy at 23 months after the first visit. LGNECS is a newly proposed, extremely rare entity that has been reported under various names, including primary cutaneous carcinoid tumor. In the present case, this tumor shows a slow‐growing nature and favorable prognosis, even though it harbors metastatic potential.

Dear Editor, Steatocystoma, originating from nevoid malformations of the pilosebaceous duct junction, is classified into steatocystoma multiplex (SCM) and steatocystoma simplex (SCS). The clinical manifestations of SCM differ from those of SCS: SCS is a single lesion that usually develops on the head or neck, while SCM develops on the trunk or extremities and is often inherited as an autosomal dominant trait. Brownstein described 30 cases of SCS in 1982. 1 Eleven lesions were present on the face, and the others developed on the scalp, neck, back, chest and limbs. Although several cases of SCS have been reported since then, ultrasonic analysis of SCS was described only once by Sunohara et al. 2 Here, we describe and discuss sonographic findings in a patient with SCS.A 41-year-old man presented to our hospital with a soft subcutaneous nodule under his umbilicus. The tumor had been growing slowly for more than 1 year. Physical examination revealed a soft, well-defined tumor measuring 1 cm in diameter with a smooth surface (Fig. 1a). The patient's family history was unremarkable, and we could not find any other skin tumors. Ultrasonographically, the nodule was well circumscribed and exhibited heteroechogenicity with the lateral shadows; it was "doughnut" shaped, with a small hypoechoic cystic lesion in the center (Fig. 1b). When we divided the resected specimen in half, the cyst contained the serous fluid and the viscous contents (Fig. 1c). Histopathological examination revealed an empty cyst attached to sebaceous glands in the dermis. The cyst wall was composed of several layers of squamous epithelium and hyalinized eosinophilic cuticle in the inner epithelium surface (Fig. 1d,e). The differential diagnosis included epidermal cyst, vellus hair cyst and SCS. Epidermal cyst was excluded by adhesion of sebaceous gland. We excluded vellus hair cyst because the cyst included no vellus hair. Based on these findings, we diagnosed the tumor as SCS.Some case reports of SCM have been accompanied by the ultrasonographic findings. 3-5 Mester et al. reported a case of SCM with sonographic examination. They stated the lesions were well defined and hypoechoic, and some of them contained fluid-debris levels (i.e. because the oily component was hypoechoic and the keratinous debris was isoechoic, there was a fluid-debris level between these two materials). 3 Park et al. examined 18 SCM lesions in five women. Fifteen of the lesions were hypoechoic and the others were isoechoic. 4 Wan et al. described ultrasonic features of SMC associated with a 59-year-old woman. The patient had multiple small nodules on the chest wall, axillae and forearm. On ultrasonography, the nodules were hypoechoic, mixed echoic and isoechoic lesions with well-circumscribed margins. 5 Previous SCM case reports have not described the aforementioned "doughnut"-shaped features (hypoechoic lesion in the center of an isoechoic cyst) present in our patient. Sunohara et al. described two cases of SCS in 2-year-old and 4-monthold girls. Ultrasonography revealed a well-d...

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Dear Editor, Spitz nevus is a variant of melanocytic nevus characterized by spindle and/or epithelioid tumor cells. It usually develops on the face or neck; only three cases of Spitz nevus on the palm have been reported. 1-3 Herein, we describe a case of Spitz nevus on the palm, in which crista dots/dotted lines were observed by dermoscopic examination.A 16-year-old male presented to our hospital for evaluation of an asymptomatic pigmented lesion, located on the right palm ( Fig. 1a). He had noticed a pigmented spot 1 year previously but received no treatment. Afterwards, the spot enlarged gradually and comprised a striated pigmented lesion that measured 1 mm 9 5 mm. By dermoscopic examination, we detected non-typical parallel furrow pattern (PFP) with crista transverse dots/dotted lines and three subtle spike projections adjacent to the cristae cutis ( Fig. 1b). We resected the lesion, and histopathological examination revealed several small nests in the lower half of the epidermis, composed of large epithelioid-shaped melanocytes. Artifactual clefts were observed between tumor nests and epidermal cells ( Fig. 1c,d). No melanocytes were seen in the dermis. Based on these findings, we diagnosed the lesion as junctional Spitz nevus.Spitz nevus was first described by Sophie Spitz in 1948. It is also known as spindle and epithelioid cell nevus. It usually develops on the face or neck in the first two decades and consists of a dome-shaped; hairless; and red, skin-colored, brown or black nodule. 4 Because our case indicated a brown-colored striated lesion and melanin pigment in histopathological examination, a more precise diagnosis may be Reed nevus, a variant of Spitz nevus. Some cases of Spitz nevus are difficult to differentiate from malignant melanoma based on clinical and/or histopathological manifestation. Dermoscopic examination is useful in differentiating Spitz nevus and malignant melanoma. 2 Dermoscopic patterns most commonly associated with Spitz nevus are starburst; negative network; and thickened dark reticular, globular and homogenous patterns. 5 However, we could not detect these typical patterns; rather, we observed only PFP with crista transverse dots/dotted lines and subtle projections. In addition, dermoscopy showed dots/dotted lines on both furrows and ridges, which would correlate with nests of melanin-laden melanocytes on both cristae profundae limitans and intermedia.Dermoscopic examination was performed in two previous cases of Spitz nevus on the palm. Yasuma et al. described a 9year-old girl with a pigmented macule of 1-year duration on her palm. Dermoscopic examination revealed blackish diffuse pigmentation with starburst and PFP. 2 Histopathological examination revealed compound Spitz nevus. Vaccaro et al. described a 28-year-old woman with a 2-month history of a rapidly growing Spitz nevus on her palm. 3 PFP, large radial projections and a globular pattern were observed by dermoscopic examination. Histopathologically, this case was junctional Spitz nevus, similar to ours. In our case, PFP ...

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