Bronchial adenocarcinoid tumor metastatic to skin

A case of advanced rectal adenocarcinoid tumor with long-term survival

Adenocarcinoid tumor most commonly occurs in the appendix and a tumor arising in the rectum is extremely rare. A 58-year-old man underwent total pelvic exenteration with extended lateral lymph node dissection for rectal adenocarcinoid tumor invading the urethra with lateral lymph node metastasis. Microscopically and immunohistochemically, the tumor consisted of carcinoid-like components and signet-ring-cell-carcinoma-like components, and an adenocarcinoid tumor was diagnosed. Postoperatively, the patient received combination chemotherapy of fluorouracil and leucovorin as an adjuvant therapy. Three years and 5 years after the initial surgery, the patient developed left groin and left external iliac lymph node recurrences, and lymphadenectomy was performed each time. As a result, the patient is alive more than 5 years after the initial surgery. There is no consensus on the indication of surgical treatment for adenocarcinoid tumor. However, in advanced cases, an aggressive surgical procedure might result in long-term survival when resectable.

Endobronchial adenocarcinoma with endometrioid features and prominent neuroendocrine differentiation. A variant of fetal adenocarcinoma

An endobronchial tumor, resected from a 77-year-old man, had an endometrioid histologic pattern consistent with fetal adenocarcinoma. A distinctive feature of the neoplasm was prominent neuroendocrine differentiation, including single, discrete neuroendocrine cells; aggregates of neuroendocrine cells resembling miniature carcinoid tumors; and a single focus of undifferentiated small cell carcinoma. Immunohistochemical staining of neuroendocrine cells revealed the presence of neuron-specific enolase, chromogranin, somatostatin, insulin, and serotonin. The heterogeneous cell populations caused problems in differential diagnosis and histologic classification. This case demonstrates that fetal adenocarcinoma may occur as a central endobronchial mass and express a variable degree of neuroendocrine differentiation.

Neoplastic nature of argyrophil cells in urachal adenocarcinoma

The histological, histochemical and electron microscopic features of the metastatic tumors of an urachal adenocarcinoma, were presented. Metastatic tumor nodules in the lungs and brain as well as the primary tumor showed tubular adenocarcinoma containing many argyrophil cells. Immunoperoxidase examination revealed three kind of endocrine cells which contained different endocrine hormones. Electron microscopic examination showed small, round endocrine granules in the endocrine cells and desmosome-like complexes in between these cells and the adjacent glandular neoplastic cells. These findings suggested that the endocrine cells were neoplastic in nature and originated from primitive neoplastic cells as well as glandular neoplastic cells.