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Von Zumbusch generalized pustular psoriasis (GPP) is the most severe type of psoriasis with possible life-threatening complications. We report the case of a 22-year-old woman who presented with a severe eruption of generalized pustular psoriasis 48 hours after receiving an injection of etanercept (Enbrel).

OBJECTIVES/OBJECTIVE:Neuroendocrine tumors (NETs) are uncommon tumors that exhibit a wide range of neuroendocrine differentiation and biological behavior. Primary NETs of the kidney, including carcinoid tumor, small cell carcinoma (SCC), and large cell neuroendocrine carcinoma (LCNEC) are exceedingly rare. MATERIALS AND METHODS/METHODS:The clinicopathologic features of renal NETs diagnosed at a single institution were reviewed along with all reported cases in the worldwide literature. RESULTS:Eighty renal NETs have been described, including nine from our institution. Differentiation between renal NETs and the more common renal neoplasms (renal cell carcinoma, transitional cell carcinoma) can be difficult since clinical, radiographic, and histopathologic features overlap. Immunohistochemical staining for neuroendocrine markers, such as synaptophysin and chromogranin, can be particularly helpful in this regard. Renal carcinoids are typically slow-growing, may secrete hormones, and pursue a variable clinical course. In contrast, SCC and LCNEC often present with locally advanced or metastatic disease and carry a poor prognosis. Nephrectomy can be curative for clinically localized NETs, but multimodality treatment is indicated for advanced disease. CONCLUSIONS:A spectrum of NETs can rarely occur in the kidney. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. Diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical neuroendocrine markers.

OBJECTIVES/OBJECTIVE:To report cases of primary neuroendocrine tumours (NETs) of the kidney, including carcinoid tumour, large cell neuroendocrine carcinoma (LCNEC) and small cell carcinoma (SCC), which show a wide range of NE differentiation and biological behaviour, and are exceedingly rare. PATIENTS AND METHODS/METHODS:The clinicopathological features of all nine renal NETs diagnosed during a 7-year period were reviewed. RESULTS:Six carcinoids, two SCC and one LCNEC were identified from 2780 kidney tumours. No patient had carcinoid syndrome or other NE symptoms. Three of six carcinoids and no SCC/LCNEC arose in horseshoe kidneys. The mean size of the six carcinoids and three SCC/LCNEC was 4.8 cm and 12.2 cm, respectively. No carcinoid had tumour necrosis or mitosis. By contrast, three SCC/LCNEC had extensive tumour necrosis and brisk mitosis. All renal NETs were positive for synaptophysin but were variably positive for chromogranin and CD56. Three of six carcinoid tumours were confined to the kidney, and four of five patients were disease-free at a mean (range) of 26 (6-74) months. One patient with nodal metastases has had no recurrence and another died with liver metastases. Three patients with SCC/LCNEC each presented with locally advanced disease and extensive lymphadenopathy; two of them died from distant metastasis or local tumour progression, and the third is currently alive with disease. CONCLUSIONS:Various NETs can occur in the kidney, but rarely. Renal carcinoids have a variable clinical course; SCC and LCNEC are associated with poor clinical outcomes. The diagnosis of NETs, especially LCNEC, requires awareness of their rare occurrence and prudent use of immunohistochemical NE markers.