Argentaffin endocrine carcinoma (carcinoid) of the pancreas with concomitant breast metastasis: an immunohistochemical and electron microscopic study

The rare entity of bilateral and unilateral neuroendocrine metastases to the breast: a case series and literature review

Introduction

Primary neuroendocrine neoplasms (NENs) in the breast are very rare. Until 2011, the prevalence was 0.1% of all breast lesions and 1% of all NENs, whereas metastatic breast NENs represent 1%–2% of all breast tumours. However, it seems that over the last 5 years the diagnostic frequency of breast NENs has increased, probably for more alert specialists and advanced diagnostic tools, leading to a prevalence of 2%–5% of diagnosed breast cancers, mostly in the elderly population. Breast metastases from extramammary malignancies are uncommon and bilateral ones are even more uncommon, with few reported in the literature. We describe four clinical settings of breast metastases from different NENs and the multidisciplinary approach for diagnosis and treatment.

Methods

Four patients were found to have NEN primaries metastasised to the breast. A literature review was conducted to identify similar cases and characterise breast metastases from neuroendocrinal tumors (NETs).

Results

Two patients presented with bilateral breast metastases (one with well-differentiated panNET and another with atypical lung carcinoid) and two had unilateral (one with moderately differentiated lung NET and one with atypical lung carcinoid). There are about 13 cases of NEN breast metastases reported in the English literature. The ileum is the most common primary site, followed by the appendix, duodenum, pancreas and lung.

Conclusion

Breast lesions from extramammary primary often pose a diagnostic challenge, since a breast nodule can be the first and often the only presentation of the disease. However, differentiating between primary and secondary NEN breast lesions is essential, owing to different clinical management and prognosis.

Ileal Carcinoid Metastatic to the Breast. Report of a Case

We report a case of ileal carcinoid which clinically presented as a primary breast carcinoma. Review of the literature demonstrated only 9 cases of carcinoids metastatic to the breast. In spite of the rarity of this event, the differential diagnosis between primary and metastatic carcinoid of the breast should be considered in view of the different clinical management of these two settings.

Metastatic carcinoid tumor to the breast: report of two cases and review of the literature

The breast is an unusual site for carcinoid metastasis. Due to increasing survival rates for carcinoid tumors, however, awareness of their rare complications is important. Carcinoid metastasis to the breast typically presents as a palpable breast mass or a mass on screening mammogram. Because imaging findings are nonspecific, the diagnosis is established through histological findings of neuroendocrine features corresponding with the known primary carcinoid pathology. Correctly distinguishing metastatic carcinoid from primary breast carcinoma is crucial to avoid more invasive procedures required for the latter. Two cases of metastatic carcinoid to the breast are presented with review of the literature.

Comparison of metastatic neuroendocrine neoplasms to the breast and primary invasive mammary carcinomas with neuroendocrine differentiation

Metastatic neuroendocrine neoplasms to the breast may show considerable morphologic overlap with primary mammary carcinomas, particularly those showing evidence of neuroendocrine differentiation, and may be misdiagnosed as such. Accurate distinction between these two entities is crucial for determination of appropriate clinical management. The histologic and immunohistochemical features of metastatic neuroendocrine neoplasms to the breast were studied and compared with the features of primary invasive mammary carcinomas with neuroendocrine differentiation, which served as controls. Of the metastatic neuroendocrine neoplasms, 15 were well-differentiated neuroendocrine tumors with carcinoid tumor-type morphology and 7 were poorly differentiated/high-grade neuroendocrine carcinomas with small-cell or large-cell neuroendocrine carcinoma morphology. The majority of the metastatic neoplasms originated in the lung and gastrointestinal tract. There were histologic similarities between metastatic neuroendocrine neoplasms and invasive mammary carcinomas with neuroendocrine differentiation, both of which exhibited neuroendocrine histologic features (nested and trabecular architecture, minimal tubular differentiation, and characteristic nuclear features). Only one case of the invasive mammary carcinomas with neuroendocrine differentiation was modified Bloom-Richardson grade 1 (largely due to minimal tubular differentiation on most such tumors), and the invasive mammary carcinomas with neuroendocrine differentiation were often associated with in situ carcinoma. Immunohistochemistry was helpful in distinguishing metastatic neuroendocrine neoplasms from invasive mammary carcinomas with neuroendocrine differentiation. Whereas the majority of invasive mammary carcinomas with neuroendocrine differentiation were positive for estrogen receptor and GATA3, metastatic neuroendocrine neoplasms were typically negative for estrogen receptor and GATA3, and metastatic well-differentiated neuroendocrine tumors often showed immunoreactivity for site-specific markers. Although the histologic and immunohistochemical features of a breast tumor may raise the suspicion of a metastatic neuroendocrine neoplasm, the pathologic findings should be interpreted in the context of the clinical history and imaging findings in order to establish an accurate diagnosis.

Classification and pathology of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are composed of cells with a neuroendocrine phenotype. The old and the new WHO classifications distinguish between well-differentiated and poorly differentiated neoplasms. All well-differentiated neoplasms, regardless of whether they behave benignly or develop metastases, will be called neuroendocrine tumours (NETs), and graded G1 (Ki67 <2%) or G2 (Ki67 2-20%). All poorly differentiated neoplasms will be termed neuroendocrine carcinomas (NECs) and graded G3 (Ki67 >20%). To stratify the GEP-NETs and GEP-NECs regarding their prognosis, they are now further classified according to TNM-stage systems that were recently proposed by the European Neuroendocrine Tumour Society (ENETS) and the AJCC/UICC. In the light of these criteria the pathology and biology of the various NETs and NECs of the gastrointestinal tract (including the oesophagus) and the pancreas are reviewed.

Serotonin-producing enterochromaffin cell tumors of the pancreas: clinicopathologic study of 15 cases and comparison with intestinal enterochromaffin cell tumors

OBJECTIVES

Serotonin-producing tumors of the pancreas are rare endocrine neoplasms composed of enterochromaffin (EC) cells that have been mainly described in the literature as case reports. This study analyzes the clinicopathologic features of a series of pancreatic EC cell neoplasms and their similarities to and differences from intestinal EC cell tumors.

METHODS

The morphological, immunohistochemical, ultrastructural, and fluorescent in situ hybridization features of 15 pancreatic and 20 intestinal serotonin-producing neoplasms were compared. In addition, we reviewed the literature on pancreatic serotonin-producing tumors to better understand the clinicopathologic features of this rare tumor type.

RESULTS

The lack of substance P and acidic fibroblast growth factor immunoreactivity; the low immunohistochemical expression of CDX2, vesicular monoamine transporter 1, connective tissue growth factor, and prostatic acid phosphatase; the lack of S100-positive sustentacular cells; the strong expression of vesicular monoamine transporter 2; and peculiar ultrastructural features characterize pancreatic EC cell tumors and differentiate them from intestinal ones, although both categories show similar chromosome 18 cytogenetic alterations. The review of the literature indicates that pancreatic functioning tumors associated with the carcinoid syndrome arise in younger patients and are larger, more frequently malignant, and more aggressive neoplasms than pancreatic nonfunctioning ones.

CONCLUSIONS

Pancreatic EC cell tumors show several different morphological features compared with related intestinal tumors despite similar cytogenetic alterations on chromosome 18.

Site-specific biology and pathology of gastroenteropancreatic neuroendocrine tumors

The gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are composed of cells with a neuroendocrine phenotype. Well-differentiated tumors, well-differentiated carcinomas, poorly differentiated carcinomas, functioning tumors (with a hormonal syndrome), and nonfunctioning tumors are identified. To predict their clinical behavior, these neuroendocrine tumors are classified on the basis of their clinicopathological features, including size, local invasion, angioinvasion, proliferative activity, histological differentiation, and metastases, into neoplasms with benign, uncertain, low-grade malignant and high-grade malignant behavior. In addition, a tumor/nodes/metastases classification and a grading system are presented. In the light of these criteria, the various GEP-NET entities are reviewed.

Carcinoid tumors in the breast

BACKGROUND

Carcinoid tumors in the breast are rare. Most represent metastases from other primary sites, but commonly are mistaken for primary breast lesions.

METHODS

A literature search of the English language found 59 cases of carcinoid tumors in the breast, 21 (36%) of which were metastases.

RESULTS

We present an additional 3 cases of carcinoid tumors metastatic to the breast and discuss the clinical, radiologic, and pathologic manifestations.

CONCLUSIONS

It is important to differentiate between primary breast carcinoid tumor and metastatic disease to the breast because of differences in treatment. All palpable breast masses and mammographically detected lesions should undergo a biopsy examination. In those patients with a known history of carcinoid tumor, pertinent clinical history, and previous surgical specimens should be reviewed to avoid an unnecessary mastectomy. If there is no history of a prior carcinoid tumor, a thorough work-up to look for an occult primary tumor elsewhere should be performed.

[Pancreatic carcinoid]

Carcinoid tumours arise from argentaffine cells or from a primitive stem cells which may differentiate into anyone of a variety of adult endocrine-secreting cells. Carcinoid tumour of the pancreas is a very rare tumour with less than 50 cases reported in world literature. In literature it is denoted "pancreatic serotoninoma" or "serotonin-producing pancreatic tumour". Due to its rarity the tumour is an unusual cause of carcinoid syndrome. As the carcinoid tumour of the pancreas does not always causes carcinoid syndrome its absence does not necessarily exclude the existence of the tumour. The tumour is frequently malignant. Over 50% of patients have metastases at the time of surgery. This is the reason why radical surgery is not possible in a number of patients. Excisional surgery offers the best chance for recovery or long term survival. We report on a 57-year-old woman with carcinoid syndrome caused by malignant carcinoid tumour of the head of the pancreas without liver or other distant metastases; it was successfully excised with pylorus preserving cephalic duodenopancreatectomy (after Longmire-Traverso) and radical lymphadenectomy. The diagnosis was established on the basis of histologic and immunohistochemical findings. The patient is symptom free for more than eight months.

Carcinoid tumors of the pancreas. Status report based on two cases and review of the world's literature

CONCLUSION

The diagnosis of a pancreatic carcinoid should be based on the measurement of serotonin in serum or its demonstration in the tumor and/or by the measurement of its derivative (5-HIAA) in urine. Carcinoid of the pancreas is a rare but definite entity; usually having metastasized by the time of diagnosis. The term "serotonin-producing tumor of the pancreas" has been suggested as an alternative designation for "pancreatic carcinoid."

BACKGROUND

The literature on carcinoid tumors of the pancreas is confusing because much of it preceded the development of the more specific immunological, chemical and staining techniques currently available.

METHODS

43 case reports were collected from the world's literature, based on a demonstrable pancreatic neuroendocrine tumor plus a positive finding of at least one of the following without another dominant hormone being demonstrated: elevation of 5-Hydroxytryptamine (5-HT) (serotonin) in the serum or detected in tumor tissue, and/or elevation of 5-Hydroxyindole acetic acid (5-HIAA) in the urine. In addition to these two hormone-specific assays, information was collected on the silver-staining properties of the tumor; properties which have traditionally been associated with carcinoid tumors. Positive silver staining in tumor cells (argyrophilic and/or argentaffin reaction) is strongly indicative of the carcinoid tumor but the findings are less specific than the hormone assays and immunohistologic stains.

RESULTS

In this review of 43 cases, including two current ones, the pancreatic carcinoid tumor has the following important features: 1. It is a rare tumor that is usually diagnosed late when the tumor is large and has metastasized. Thirty-eight (88.4%) have been malignant. They are, therefore, associated with a high incidence of the "carcinoid syndrome." 2. To date, prognosis in therapy is poor, based on delayed diagnosis, a resultant low incidence of resectability, and an uncertain duration of survival after resection. 3. Pancreatic carcinoid tumors remain difficult to differentiate from other endocrine tumors. The measurement of urinary 5-HIAA excretion or the demonstration of elevated serotonin level in the tumor or in serum is essential to its distinction. Silver staining of the tumor, although of historic importance, has been superceded by the hormone-specific studies. 4. To distinguish it from other endocrine tumors of the pancreas, the terms "pancreatic serotoninoma" or "serotonin-producing tumor of the pancreas" have been suggested as possible alternatives. Its growth characteristics may be related more to its cell of origin than to its extent of hormone secretion. Not all of the tumors result in recognizable hyperserotoninemia.

Bronchial carcinoid tumor metastatic to the breast

We report a case of bronchial carcinoid that initially manifested as metastatic tumor in the breast. An exhaustive search for the primary tumor yielded the finding of a large right lung mass. Subsequent histopathologic examination of the resected lung and breast tissues confirmed the lung cancer as a primary tumor and the breast tumor as metastatic disease.

Carcinoid of the pancreas: clinical characteristics and morphological features

The classical carcinoid tumour (WHO) of the pancreas is extremely rare and its diagnosis may puzzle physicians and pathologists. Here, 29 previously published cases of pancreatic carcinoid tumours, including one new case, are reviewed. Literature research was done using MedLine from 1966 to 1995. Pancreatic carcinoids produce an atypical carcinoid syndrome. Skin flushing was reported in only 34%. The main symptom was pain, followed by diarrhoea and weight loss. Elevated urinary 5-HIAA levels were found in 85% (17/20). The immunocytochemical sensitivity for serotonin was 100% (11/11). The diagnosis of pancreatic carcinoid tumour is based on the typical endocrine histological features together with increased serotonin metabolism. Generally, the slow growth rate and late invasion of adjacent organs render local resection possible, but the high incidence of distant metastases (69%) prevents long-term survival in the majority of patients. The possible role of the Octreoscan, a new radionuclide imaging technique, is discussed with regard to this tumour entity.

Carcinoid tumors of the pancreas: CT findings

Computed tomographic (CT) and ultrasound (US) findings in four cases of carcinoid tumors of the pancreas are reported. Differential diagnosis with other endocrine and nonendocrine pancreatic tumors is discussed. CT and US techniques play an important role in diagnosis, prognosis, and treatment of these tumors.

Primary carcinoid of the kidney. Immunohistochemical and ultrastructural studies of five patients

BACKGROUND

Primary carcinoid tumor of the kidney is rare; only 18 patients have been reported. Because of the rarity of the lesion, its prognosis and clinicopathologic features are not well characterized, and its histogenesis is unknown.

METHODS

Clinicopathologic, immunohistochemical, and ultrastructural studies were performed on five patients with primary carcinoid tumor of the kidney.

RESULTS

Age of the patients ranged from 42 to 63 years, with a mean of 53.2 years. Only one patient had a carcinoid syndrome. Three were men, and two were women. In each patient, the tumor was solitary and confined to the kidney. All tumors had histologic features identical to those of carcinoid tumors affecting other sites. The cytoplasmic granules of the tumor cells were reactive with Grimelius stain in all patients. All tumors also were immunoreactive for keratin, neuron-specific enolase, and chromogranin, but only two patients had tumors that reacted for serotonin, pancreatic polypeptide, and vasoactive intestinal polypeptide. Ultrastructural studies showed numerous intracytoplasmic neuroendocrine granules in four tumors. One patient had Robson Stage I cancer, and two each had Stage II and IV cancer. The two patients with Stage IV tumor died of disease at 36 months and 28 months after diagnosis; one patient with Stage II carcinoid is alive without clinical evidence of residual disease 8 years after control of metastases; the other patient with Stage II and the patient with Stage I cancer are alive and well without evidence of disease at 36 months, and 2 months, respectively.

CONCLUSION

Tumor stage at presentation appears to be the most important factor in determining outcome. The number of mitoses and degree of cellular atypia appear to be important pathologic parameters in predicting prognosis, despite the limited number of patients reported in this report.

Upper abdominal neoplasms: an introduction and selected references

The organs in the upper half of the abdominal cavity can give rise to a highly heterogeneous collection of neoplasms that encompasses a broad spectrum of clinical features, light microscopic appearances, immunostaining properties, and fine structure. Because of the anatomic proximity of the viscera in this region, the differential diagnosis of an upper abdominal mass may include consideration of tumors that arise from the stomach, duodenum, liver, kidney, adrenal, and pancreas. There are many distinctive ultrastructural features among the various tumors that can be used effectively by the diagnostic electron microscopist, but it is also important to take into account the considerable overlap in fine structure that occurs among different tumors and among similar tumors from different organs. In the session on upper abdominal neoplasms, the electron microscopic characteristics of the common tumors of each viscus were reviewed before the presentation of individual case studies that incorporated original observations and illustrated some unusual entities. The selection of cases that follows is inevitably small and arbitrary, but the cases demonstrate the contribution that electron microscopy can make in the study of an upper abdominal mass and illustrate some of the similarities that can be encountered among tumors of different organs.

Malignant oncocytic carcinoid of the pancreas

We report a rare case of malignant oncocytic carcinoid of the pancreas including the diagnostic immunocytochemical and electron microscopic findings. In addition the tumor shows some unusual ultrastructural features: lamelliform cristae and cytoplasmic and nuclear crystalline structures.

Chronic pancreatitis and pseudocyst formation secondary to carcinoid tumor of the pancreas

The incidence of chronic pancreatitis has been increasing in the western world. Although chronic alcohol abuse accounts for 90% of adult cases, the physician must be aware of the multiplicity of causes for chronic pancreatitis. We present a case of obstruction of the pancreatic duct and chronic pancreatitis caused by a primary carcinoid tumor.

Pancreatic endocrine tumors

In this review the current state of our understanding of endocrine tumors of the pancreas is considered. It is based on the experience with a series of 365 tumors. The first part of the article focuses on origin and classification, markers, frequency, criteria of malignancy as well as general structural features of the pancreatic endocrine tumors. In the second half of the article the functioning tumors, i.e. tumors that cause hormonal syndromes, and the nonfunctioning tumors as well as the endocrine tumors associated with multiple endocrine neoplasia type 1 are dealt with in detail. Special emphasis is put on the immunocytochemical profile and the biological features of the respective tumors.

Carcinoid metastatic to breast diagnosed by fine-needle aspiration biopsy

We report a patient in whom fine-needle aspiration biopsy of a breast mass, clinically suspected to be a mammary adenocarcinoma, established the diagnosis of a carcinoid metastatic to breast. The aspirate smears resembled a primary breast carcinoma; however, subtle cytomorphologic differences were present. Ultrastructural and immunohistochemical studies of the aspirate material confirmed the diagnosis of metastatic carcinoid.