Primary low-grade neuroendocrine carcinoma of the skin: An exceedingly rare entity.

Low-grade neuroendocrine tumors (NETs), also known as carcinoid tumor, commonly arise from the gastrointestinal (GI) and pulmonary tracts, but rarely occur in the skin. Cutaneous NET typically occurs as metastases or high-grade primary lesions, called Merkel cell carcinoma. In the few cases described in literature, primary low-grade neuroendocrine carcinomas of the skin (LGNECS) are usually indolent cutaneous nodules, presenting on the head and trunk of elderly patients. LGNECS tumors are histologically similar to its counterparts arising in other anatomic locations. As there is no NET cut-off for the skin due to their rarity, the GI scale was used instead; low-grade NETs have a Ki-67 proliferative index of less than 3%. The distinction between primary and metastatic NET, however, is not absolute and can be difficult. A primary vs metastatic NET diagnosis relies on clinical exclusion of a NET in other, more common, anatomic locations. Here, we present a case of an LGNECS on the scalp of a 72-year-old female patient. Whole body imaging failed to identify any octreotide-avid lesions elsewhere in the patient, aside from 2 positive cervical lymph nodes, which were confirmed with a node dissection and histologic evaluation. This is the 19th reported case of LGNECS and the 2nd reported case of LGNECS with nodal metastasis.

Clear cell carcinoma in a background of endometriosis. Case report of a finding in a midline abdominal scar 5 years after a total abdominal hysterectomy.

BACKGROUND: Endometriosis is considered a premalignant process whose association with carcinoma is well documented. We discuss a case of clear cell carcinoma with an unusual presentation in that it was located outside the abdominal cavity and was the only lesion noted clinically and radiologically. The histopathologic diagnostic criteria will be reviewed, as will the association of carcinomas with endometriosis. Furthermore, we will review the current literature of extraovarian clear cell carcinoma associated with endometriosis with regard to clinical outcome. CASE: A 42-year-old Hispanic woman presented to the Fine Needle Aspiration (FNA) Clinic at Parkland Hospital, Dallas, Texas, in August 2005 secondary to a growing area of firmness associated with her midline abdominal hysterectomy scar. A single mass anterior to the abdominal wall was identified radiologically. The FNA sample was reported as highly atypical cells suspicious for adenocarcinoma. Excision of this mass revealed a clear cell carcinoma in a background of endometriosis. CONCLUSION: Clear cell carcinoma is one of the most prevalent carcinomas associated with endometriosis, whether identified in the ovary or extraovarian site. This case is perplexing because the mass was a solitary lesion and the patient never had documented endometriosis. The unusual presentation may make survival difficult to predict.