Rare syndromes

Primary Mesenteric Carcinoid Tumor Presenting with Carcinoid Syndrome

Neuroendocrine neoplasms (NENs) are a diverse group of tumors arising throughout the body with a common origin from neuroendocrine cells. Well-differentiated NENs, also known as neuroendocrine tumors (NETs), are generally indolent and are often found incidentally, while poorly differentiated tumors are more aggressive. Carcinoid tumors are NETs arising from the gastrointestinal tract and less commonly from the lungs, thymus, and kidneys. NETs in the mesentery arise from metastasis from primary tumor, and carcinoid syndrome in this setting results from concomitant metastasis to the liver. Primary mesenteric carcinoid tumors are very rare. We present a 64-year-old man with carcinoid syndrome from a mesenteric carcinoid tumor without evidence of liver metastasis or other primary tumor sites.

Red face revisited: Flushing

The term red face is reserved for lesions located exclusively or very predominantly on the face that result from changes in cutaneous blood flow triggered by multiple different conditions. Facial erythema may not only present clinically as a distinct entity, but can also be a sign of other diseases. Patients with a red face challenge clinicians to consider a broad differential diagnosis. Diagnosis is based on date and mode of appearance, characteristics of the erythema, functional signs, and associated systemic manifestations. In most cases, the cause is a benign disease such as rosacea, contact dermatitis, photodermatosis, and climacterium, and a thorough history and physical examination is enough to make a diagnosis; facial erythema may also present as a symptom of drug allergies, cardiac disease, carcinoid syndrome, pheochromocytoma, mastocytosis, and anaphylaxis, as well as some rare causes such as medullary carcinoma of the thyroid, pancreatic cell tumor, and renal carcinoma where further laboratory, radiologic, or histopathologic studies are required. In this review, the mechanisms of flushing, its clinical differential diagnosis, and management of various conditions that cause flushing are discussed.

Multiple Glucagon-Producing Pancreatic Neuroendocrine Tumors in a Horse (Equus caballus)

Pancreatic neuroendocrine tumors of glucagon-producing cells are extremely rare in domestic animals. In this report, we describe for the first time, to our knowledge, the incidental finding of multiple glucagon-producing neuroendocrine tumors of the pancreas of a horse. The animal was euthanized due to severe local infection after tooth extraction. On postmortem examination, multiple white nodules of up to 4 cm in diameter were observed in the pancreas. Histologically, pancreatic nodules had the appearance of neuroendocrine neoplasms with positive immunoreactivity for glucagon, synaptophysin, chromogranin A, and neuron-specific enolase. Electron microscopy revealed numerous electron-dense granules, similar to those observed in normal pancreatic alpha cells, in the neoplastic cells. In addition, the left adrenal gland showed multiple hyperplastic foci and adenomas in the medulla that were identified as pheochromocytomas. Based on the morphologic appearance and immunohistochemical staining pattern of pancreatic nodules, a diagnosis of multiple glucagon-producing neuroendocrine tumors was made.

Skin lesions in hereditary endocrine tumor syndromes

OBJECTIVE

To review the main cutaneous manifestations of hereditary endocrine tumor syndromes and discuss currently known molecular mechanisms involved in their pathogenesis.

METHODS

On the basis of our collective experience and a comprehensive MEDLINE literature search of the English-language literature published between January 1957 and September 2010 using the search terms "skin," "cutaneous," "multiple endocrine neoplasia," "Carney complex," and "McCune-Albright syndrome," we reviewed the dermatologic findings in multiple endocrine neoplasia type 1 and type 2, Carney complex, and McCune-Albright syndrome.

RESULTS

Although the category of hereditary endocrine tumor syndromes consists of a broad spectrum of conditions, only the aforementioned few are prominently associated with cutaneous features. Because the cutaneous findings associated with these diseases are generally benign, they are often ignored or dismissed as ancillary findings in the context of severe systemic involvement. Accordingly, the pertinent literature is relatively scarce and often fails to provide a comprehensive insight about this issue. Nevertheless, timely recognition of such dermatologic manifestations may have a critical role in the early diagnosis and appropriate management of the related syndromes. Moreover, specific genotype-phenotype correlations may convey important prognostic implications.

CONCLUSION

Many physicians are unfamiliar with the cutaneous findings in the hereditary endocrine tumor syndromes described in this review. Nonetheless, knowledge of their existence can have a major role in establishing an early diagnosis of these syndromes and determining the patient's prognosis.

Skin manifestations of hormone-secreting tumors

Endocrine and metabolic diseases, besides affecting other organs, can result in changes in cutaneous function and morphology and can lead to a complex symptomatology. Dermatologists may see some of these skin lesions first, either before the endocrinologist, or even after the internist or specialist has missed the right diagnosis. Because some skin lesions might reflect a life-threatening endocrine or metabolic disorder, identifying the underlying disorder is very important, so that patients can receive corrective rather than symptomatic treatment. In this issue, we will review various hormone-secreting tumors, including pituitary disorders (Cushing's syndrome and acromegaly), hyperthyroidism, glucagonoma, carcinoid syndrome, mastocytosis, and hyperandrogenism. We will focus on clinical manifestations, mainly cutaneous, followed by a brief discussion on how to make the diagnosis of each condition in addition to treatment options.

Carney complex and lentiginosis

Initially described as the 'complex of myxomas, spotty skin pigmentation and endocrine overactivity,' Carney complex (CNC) is known as an autosomal dominant multiple neoplasia syndrome involving skin and cardiac myxomas, pigmented skin lesions and endocrine tumors. Pigmented cutaneous manifestations in CNC are important diagnostically because they can be used for the early detection of the disease and, thus, the prevention of life-threatening complications of CNC related to heart myxomas and endocrine abnormalities. Specific for the disease skin lesions are present in more than half of the CNC patients. A major challenge is to distinguish pigmented skin lesions associated with CNC from other skin pathology, and thus accurately estimate the risk of cancer in affected patients; curiously, patients with CNC do not appear to have predisposition to skin cancers whereas this is not the case with other genetic syndromes associated with melanotic and other cutaneous lesions. In this paper, we review the current knowledge on cutaneous pathology associated with CNC and the most recent data on the molecular basis of the disease.

[Skin signs of systemic diseases]

Many aspects of cutaneous signs are of importance to nondermatologists, as skin manifestations can reflect internal disease states, either directly or as a result of a complication or treatment and therefore can lead to the diagnosis of systemic illness. Serious morbidity and mortality can be avoided by early recognition of only minor cutaneous manifestations signaling internal problems. Limited forms of collagen vascular disease exemplify the important marker function of the skin for diagnosis as well as for prognosis with their typically favorable course permitting a less aggressive treatment. The utmost important prerequisite of diagnosing skin conditions is an accurate and thorough examination of the skin, the adjacent mucous membranes and the integumentary appendages. In a first step, the primary site of the cutaneous condition should be identified (e.g. epidermal, dermal or subdermal) and then the form, the pattern, and distribution should be recognized. There are many comprehensive and excellent textbooks available for guidance. This article focuses on the more common dermatologic conditions linked to different organ systems involved (excluding infectious diseases, metabolic diseases and drug induced conditions).

Lessons from the skin--cutaneous features of familial cancer

As the molecular basis of disease continues to be elucidated, familial cancer syndromes, which consist of a range of neoplastic and non-neoplastic features, are emerging. The usual pathway of referral to a genetics clinic or familial cancer centre is via an oncologist, when high-risk features that suggest a possible hereditary basis for the presenting cancer are recognised. Traditionally, these high-risk features include more than two family members with similar cancers over two or more generations, a young age of onset, and more than one synchronous or metachronous tumour. These features are effective in ascertaining a substantial proportion of families with hereditary breast and ovarian cancer due to a BRCA mutation, or the more common bowel-cancer predisposition syndromes, such as hereditary non-polyposis colon cancer and familial adenomatous polyposis. However, there are a range of familial cancer syndromes that are not easily detected and that can remain undiagnosed when history and examination are not extended to include non-malignant features. The identification of cutaneous signs associated with rare familial-cancer syndromes provides individuals and their families with the opportunity to undertake early surveillance for malignant and non-malignant complications that might in time be shown to improve outcomes.