Case of low‐grade neuroendocrine carcinoma of the skin presenting metastases to lymph nodes and peritoneum

Abstract

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.

Primary Cutaneous Neuroendocrine Tumor of the Vulva: A Case Report

“…The diagnosis of a primary CNET was first discussed in 1975 by van Dijk and ten Seldam (4). Since then, case reports of primary CNET from different skin locations have been described in literature (5)(6)(7)(8)(9)(10). These tumors usually present as single flesh-colored nodules with a predilection for the scalp and trunk.…”

Subcutaneous metastasis from an atypical pulmonary carcinoid tumor

“…It is unknown whether patients with symptomatic cutaneous metastatic PC may benefit from palliative surgical resection. However, surgical excision has been reported in cases of primary cutaneous neuroendocrine tumors [9]. The presentation of cutaneous metastasis in surgical scar tissue secondary to resection of the primary tumor has been described in cases of colon, breast, and endometrial cancer [10][11][12].…”

Skin involvement in neuroendocrine neoplasia

“…Merkel cell carcinoma represents the high grade NEN of skin meaning a more aggressive profile (12,13). Opposite to this, LGNECS are asymptomatic nodules and due to their rarity a specific index of suspicion is necessary while specific investigations like whole body octreoscan might help (12,13). Another potential scenario is the co-presence of carcinoid syndrome like diarrhoea, flush, respiratory problems like wheezing or bronchospasm etc.…”

“…Another potential scenario is the co-presence of carcinoid syndrome like diarrhoea, flush, respiratory problems like wheezing or bronchospasm etc. (13). Metastasis from primary skin NEN have been reported, especially at local lymph nodes (13,14).…”

“…(13). Metastasis from primary skin NEN have been reported, especially at local lymph nodes (13,14). PCTS seem to affect people of a median 66 years, equally between sexes, and their evolution is less aggressive than NEN metastasis at the same level (15).…”