PubMed · 6345922
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
E A Vasiukova, G S Zefirova. 1983. [Itsenko-Cushing syndrome].. https://pubmed.ncbi.nlm.nih.gov/6345922/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
BACKGROUND: Nasopharyngeal carcinoma is endemic in Southern China and the majority of patients present with local symptoms due to the tumor. METHODS: This report describes two unusual cases of occult nasopharyngeal carcinoma in which the patients initially presented with endocrine manifestations. RESULTS: The first patient presented with Cushing's syndrome secondary to ectopic adrenocorticotropic hormone (ACTH) production. Nasolaryngoscopy showed a growth in the left nasal fossa and biopsy revealed a poorly differentiated nasopharyngeal carcinoma that exhibited positive immunostaining for ACTH. The second patient presented with a 10-month history of bone pain over both lower limbs. She was normocalcemic but her serum alkaline phosphatase was markedly elevated. A bone biopsy showed both osteoclastic and osteoblastic activity with widespread fibrosis suggestive of Paget's disease. Three months later, she developed third cranial nerve palsy. Computed tomography investigation revealed a soft tissue mass filling the sphenoid and ethmoid sinuses. Biopsy showed a poorly differentiated nasopharyngeal carcinoma. The bone biopsy was reviewed and immunohistochemistry demonstrated the presence of cells positive for the epithelial marker AE1/3 within the fibrous stroma. Radio-labeled in situ hybridization showed that Epstein-Barr virus early RNA was present in these tumor cells and the bone lesions were in fact metastases. CONCLUSIONS: Nasopharyngeal carcinoma can present with rather atypical symptoms that may lead to a delay in diagnosis. Therefore, in high risk populations, it is important to consider nasopharyngeal carcinoma as a possible primary tumor in patients with occult carcinomas.
Ectopic ACTH secretion occurs in highly differentiated and rather indolent tumors like bronchial carcinoids or, in contrast, in various types of aggressive and poorly differentiated neuroendocrine tumors. We explored this phenomenon using the recently cloned human pituitary V3 vasopressin receptor as an alternate molecular marker of the corticotroph phenotype. Expression of V3 receptor, corticotrophin releasing hormone (CRH) receptor, and proopiomelanocortin (POMC) genes was examined in tumors of pituitary and nonpituitary origin. A comparative RT-PCR approach revealed signals for both V3 receptor and CHR receptor mRNAs in 17 of 18 ACTH-secreting pituitary adenomas, and 6 of 6 normal pituitaries; in six growth hormone- or prolactin-secreting adenomas, a very faint V3 receptor signal was observed in three cases, and CRH receptor signal was undetected in all. Six of eight bronchial carcinoids responsible for the ectopic ACTH syndrome had both POMC and V3 receptor signals as high as those in ACTH-secreting pituitary adenomas; in contrast, no POMC signal and only a very faint V3 receptor signal were detected in six of eight nonsecreting bronchial carcinoids. Northern blot analysis showed V3 receptor mRNA of identical size in ACTH-secreting bronchial carcinoids and pituitary tumors. Other types of nonpituitary tumors responsible for ectopic ACTH syndrome presented much lower levels of both POMC and V3 receptor gene expression than those found in ACTH-secreting bronchial carcinoids. In contrast with the V3 receptor, CRH receptor mRNA was detected in the majority of neuroendocrine tumors irrespective of their POMC status. These results show that expression of the V3 receptor gene participates in the corticotroph phenotype. Its striking association with ACTH-secreting bronchial carcinoids defines a subset of nonpituitary tumors in which ectopic POMC gene expression is but one aspect of a wider process of corticotroph cell differentiation, and opens new possibilities of pharmacological investigations and even manipulations of this peculiar ACTH hypersecretory syndrome.
We report a rare case of ectopic ACTH syndrome associated with undifferentiated carcinoma of the ascending colon. A 62-year-old woman developed hypokalaemia and metabolic alkalosis associated with markedly elevated serum cortisol and plasma ACTH levels. High-dose dexamethasone (8 mg/day) did not suppress increased urinary 17-hydroxycorticosteroid and 17-keto-steroid excretion. Barium enema and abdominal computerised tomography showed a Borrmann II type tumour in the ascending colon, multiple metastatic nodules in the liver and bilateral enlargement of the adrenal glands. Histological examination of the resected primary colon cancer and metastatic liver tumour showed undifferentiated carcinoma with areas of distinct neuroendocrine, exocrine, and squamous differentiation. ACTH production by the tumour was confirmed by radioimmunoassay and immunohistochemistry. This is a unique case report of carcinoma of the colon with distinct multidirectional differentiation causing ectopic ACTH syndrome.