Carcinoid tumors of the testis

Testicular Neuroendocrine Tumors: A Case Report and Literature Review

Testicular neuroendocrine tumors (TNETs) are extremely rare. We report a case of a primary TNET and discuss the clinical and histological characteristics, treatment, and prognosis of this tumor. A 47-year-old man had a painless right testicular mass. All tumor markers were negative. The patient underwent a high inguinal radical orchidectomy. Histopathology revealed a well-differentiated neuroendocrine tumor. Radiological investigations showed multiple prominent axillary, supraclavicular, mediastinal, and hilar lymph nodes and no bowel or mesenteric lesions suggesting carcinoid. Once a TNET is diagnosed, it is necessary to rule out the secondary origin in the gastrointestinal tract and lungs. Radical orchiectomy is the treatment of choice for TNETs. Somatostatin analogs can be useful in patients with carcinoid syndrome, induce symptomatic improvement, and control disease progression. As this case highlights, physicians should consider TNETs in the differential diagnosis of testicular masses, as early diagnosis and treatment are crucial for good patient outcomes.

Primary testicular neuroendocrine tumor with liver lymph node metastasis: A case report and review of the literature

BACKGROUND

Primary testicular neuroendocrine tumors (TNETs) are sporadic, accounting for only 0.23% of all testicular tumors. Few cases have been reported in the literature, and no uniform treatment protocol exists. We report a case of a primary TNET with liver lymph node metastasis diagnosed at the age of 24 years and discuss its clinicopathological features, diagnosis, differential diagnosis, treatment, and prognosis.

CASE SUMMARY

We report the case of a 24-year-old patient with a primary TNET with liver lymph node metastasis. The patient was found to have a right testicular swelling of about 3 cm × 4 cm in size with unclear borders and no testicular pressure pain seven years ago without any examination or treatment. One month ago, an ultrasound examination was performed for persistent enlargement of the right testis, which showed an occupying lesion of the right testis approximately 110 mm × 102 mm × 82 mm in size. Magnetic resonance imaging scan of the testis (plain scan) showed that the right testis was an occupying lesion with inhomogeneous density and mixed signal, the boundary was still clear, and the possibility of seminoma was considered; chest X-ray and computed tomography did not show any apparent abnormalities. The patient underwent radical orchiectomy, and the pathological examination suggested a right TNET with a typical carcinoid tumor histological type. One month after the surgery, the patient received nine cycles of lanreotide chemotherapy at a dose of 90 mg/mo without adverse effects. No distant lymph node or other organ metastases were detected at follow-up. He is in good physical condition and attends regular follow-up visits.

CONCLUSION

Neuroendocrine tumors are rare in clinical practice, and the diagnosis mainly relies on the characteristics of microscopic tumor cells and immunohistochemical features. Treatment involves radical orchiectomy. If it is accompanied by distant lymph node metastasis and the metastatic lesion can be resected, it should be surgically removed; if it cannot be resected, growth inhibitor analog octreotide or lanreotide chemotherapy can be administered to obtain good results, with close postoperative follow-up to prevent recurrence and metastasis.

Complete remission of Cdx-2 positive primary testicular carcinoid tumor: 10-years follow-up and literature review

BACKGROUND

The neuroendocrine cells can cause a variety of malignancies throughout the human body known as the neuroendocrine tumors (NETs) or carcinoid tumors. The primary testicular carcinoid tumor (PTCT) accounts for less than 1% of the testicular neoplasms and for only 0.2% of all carcinoid tumors representing already a very rare neoplastic entity. Here, we present a patient with a history of an exceptionally rare primary testicular carcinoid tumor, staining positive for Cdx-2 along with a literature review.

CASE PRESENTATION

A 44-year old patient without significant past medical history was diagnosed in September 2009 with primary testicular carcinoid tumor, which was surprisingly staining positively for Cdx-2, too. At the time of the initial diagnosis the tumor was already showing histopathological infiltration of veins. DOTA-TATE-PET/CT imaging and endoscopy studies did not show any signs of distant metastases and in particular no gastrointestinal manifestation following no further medical indication for systemic chemotherapy. The continuous and close follow-up of the patient has reached a total of over 10 years at the time of publication remaining in complete remission.

CONCLUSION

The diagnosis of primary testicular carcinoid is based on histopathology. The detailed histopathologic assessment of biomarkers based on immunohistochemistry is very important for the classification and the prognosis of the primary testicular carcinoid tumor. Primary testicular carcinoid tumor with Cdx-2 positive stain outlines an exceptionally rare neoplastic entity without a consensus about general follow-up guidelines, requiring close clinical and imaging aftercare and consideration in Cdx-2 positive metastatic tumor of unknown origin.

Prospective molecular and morphological assessment of testicular prepubertal-type teratomas in postpubertal men

In 2016, the World Health Organization classification system of testicular tumors included the new entity prepubertal-type teratoma based on its morphological and molecular profile, and the realization that these tumors may occur in postpubertal men. For treatment and prognostic purposes, it is important to distinguish prepubertal-type teratoma from the usual postpubertal-type teratoma, because the former is benign unlike the latter. The distinction may be challenging. In this study, we investigated clinical, morphological, and molecular criteria for distinguishing prepubertal-type teratoma from postpubertal-type teratoma in a prospective series of pure testicular teratomas. All cases of pure teratoma in postpubertal men assessed at Barts Health NHS Trust or in consultation since the introduction of routine investigation of chromosome 12p status in 2010 were reviewed. Morphological features suggestive of prepubertal-type teratoma were observed in 14 out of 35 cases. All underwent molecular testing and none displayed 12p amplification. Mean tumor size was 16 mm (range 7-28 mm). None had associated germ cell neoplasia in situ or significant atrophy. Four incorporated a well-differentiated neuroendocrine tumor, 1-2 mm in size. Of the ten patients with follow-up information, none have recurred or metastasized. Twenty-one of the 35 cases were diagnosed as postpubertal-type teratoma, mean tumor size 40 mm (range 6-90 mm). One case underwent molecular testing: a tumor of pure skeletal muscle differentiation and possessed 12p amplification. Three cases presented with clinical metastases. Eight cases contained immature areas, ten cases had associated germ cell neoplasia in situ, and 17 cases had severe atrophy of the parenchyma. One case with neither germ cell neoplasia in situ nor atrophy showed necrosis. We conclude that both morphological and molecular features are of help in differentiating prepubertal-type teratoma from postpubertal-type teratoma. In nearly all postpubertal-type teratomas, molecular testing was unnecessary, and merely confirmed the morphological impression in the prepubertal-type teratomas. Our study confirmed the high incidence of well-differentiated neuroendocrine tumors in the prepubertal-type.

Primary Carcinoid Tumor of the Testis: A Case Report and Review of the Literature

Carcinoid tumors usually arise in the gastrointestinal tract. Immunocytohistochemical and radiologic studies are important in detecting the primary tumor site. Primary carcinoid tumors of the testis are particularly rare with a high malignant potential warranting long-term follow-up. We present the case of a primary carcinoid tumor of the testis with long-term surveillance.

Primary testicular carcinoid tumour with mature teratoma in undescended testis metastatic to lymph nodes

We report a case of primary testicular carcinoid tumour with mature teratoma metastatic to the para-aortic lymph node and the lymph node around the left gonadal vein, which was treated with radical orchiectomy, bleomycin, etoposide, and cisplatin chemotherapy, and modified retroperitoneal lymph node dissection. Three days after modified retroperitoneal lymph node dissection, bleomycin induced pneumonitis occurred, which was resolved with steroid administration. The patient is alive without recurrence 31 months after radical orchiectomy.

Benign and Malignant Neoplasms of the Testis and Paratesticular Tissue

Benign and malignant tumors of the testes and paratesticular tissues present an interesting spectrum of diagnostic entities often encountered in routine surgical pathology practice. Germ cell tumors are the most common tumors of the testes and, despite a rising incidence, have excellent prognosis because of their radiosensitivity and/or effective chemotherapeutic agents. The proper classification of these tumors aids in the choice of appropriate treatment options. This article reviews benign and malignant neoplastic entities of the testes and paratesticular tissues and illustrates the classic pathologic characteristics. The differential diagnosis, along with ancillary studies, clinical significance, and presentation are discussed also.

Neuroendocrine tumours of the urinary system and male genital organs: clinical significance

Two basic types of neuroendocrine (NE) tumours with diverse clinicopathological features and outcome are identified in the urinary system and male genital organs: carcinoid tumour and neuroendocrine carcinoma. Carcinoid, a rare tumour, occurs in the kidney, bladder, prostate and testis. It is morphologically, histochemically, immunohistochemically and ultrastructurally similar to its counterpart in other organs, such as lung or gastrointestinal tract. Metastases can be detected at the initial evaluation, although they have been reported up to several years after removal, emphasizing the need for a long-term follow-up. NE carcinoma occurs in the kidney, bladder and prostate, and includes small cell carcinoma (SCC) and large cell NE carcinoma (LCNEC), the latter being exceedingly rare. Both show the morphology and immunophenotype of NE carcinoma originating in other organs. Although the occurrence is rare, it is highly aggressive.

[Testicular carcinoid tumor associated with teratoma: with regard to a case]

We report a case of a carcinoid tumor originated in testicle associated with mature teratoma in a 31 years old male. Primary gonadal location of this tumor is unusual, moreover when associated with teratoma. Early diagnosis and treatment determine the prognostic of the patients affected of this neoplasm since the only curative potential treatment is surgery. Follow up must be extent for years due to the possibility of late relapse.

Testicular Tumors—Some New and a Few Perennial Problems

The histopathology of testicular tumors is presented, emphasizing new, unusual, or underemphasized aspects. Within the category of seminoma of the usual type, the recent literature has drawn attention to the presence in occasional tumors of solid or hollow tubules or spaces of varying sizes and shape that may result in cribriform or microcystic patterns, causing potential confusion with other neoplasms, most notably Sertoli cell tumor or yolk sac tumor. Although regions of typical neoplasia and awareness of this phenomenon usually will be diagnostic, immunohistochemistry may play a role in excluding Sertoli cell tumor or yolk sac tumor. Although immunohistochemistry can play an undoubted helpful role in this and selected other areas of testicular tumor evaluation, careful evaluation of the gross and routine microscopic features will solve the vast majority of diagnostic problems. An excellent review of immunohistochemistry in this area by R. E. Emerson, MD, and T. M. Ulbright, MD, is cited herein. Spermatocytic seminoma remains a crucial pitfall in diagnosis, and the pathologist must always be alert to the possible diagnosis when looking at a seminomatous neoplasm, particularly in an older patient, although about one third of these tumors occur in the usual seminoma age range. The embryonal carcinoma has a great diversity of patterns, which are briefly noted. The enigmatic and picturesque tumor, polyembryoma, which virtually never occurs in pure form but may be a confusing component of a variety of mixed germ cell tumors, is discussed and illustrated. The phenomenon of burnt-out germ cell neoplasia is also briefly noted and an excellent recent contribution is referred to. Within the sex cord–stromal family of neoplasms, recent contributions and elaborations of unusual morphologic features of Leydig cell tumors and Sertoli cell tumors are presented. Within the Leydig cell family, cyst formation, adipose metaplasia, calcification or ossification, and spindle cell patterns may be particularly confusing, and in the Sertoli cell family, a great array of patterns caused by differing admixtures of tubular, solid, and stromal components occur. The peculiar lesion, intratubular large cell hyalinizing Sertoli cell tumor, of young boys with Peutz-Jeghers syndrome, is briefly discussed. Some of the problems in the family of hematopoietic neoplasms are reviewed, these processes posing diverse problems in differential diagnosis and their correct recognition having crucial therapeutic implications. Although secondary tumors to the testis have not received the same attention in the literature as the similar phenomenon in the female gonad, remarkable examples of testicular spread of diverse neoplasms, usually carcinoma but rarely melanoma, are seen, and the pathologist should be alert to this possibility, particularly when examining an unusual morphology in an older patient. Finally, a few comments are made on the common paratesticular neoplasm, the adenomatoid tumor, highlighting its varied patterns and recent description of some of the issues that may arise when they undergo total or subtotal infarction.

Neuroendocrine lesions of the genitourinary tract

Neuroendocrine differentiation in tumors of the upper and lower urinary tracts, prostate, and testis is rare. The current review surveys the most significant pathologic and clinical features of primary neuroendocrine lesions at these sites, with emphasis on the cell types from which they derive. As many tumors in this spectrum often bear strong morphologic resemblance to similar neoplasms in other organs, the importance of considering secondary involvement of the genitourinary tract cannot be overstated.

Morphological approach to tumours of the testis and paratestis

Most neoplastic scrotal masses ultimately prove to be germ cell tumours and are recognisable with routine haematoxylin and eosin-stained sections. The differential diagnosis may be focused, even before reviewing histological sections, by knowledge of patient age, medical history, tumour site (testicular vs paratesticular) and gross findings. Some cases may prove to be diagnostically challenging, including rare tumours, a common tumour with an unusual pattern, a metastatic tumour, or a neoplasm with features that mimic another tumour. Several morphological patterns are seen with some frequency and these generate recurring sets of differential diagnostic considerations. These common patterns include testicular tumours with a predominant diffuse arrangement of cells with pale to clear cytoplasm, tumours with a glandular/tubular pattern, tumours with a microcystic pattern and tumours composed of oxyphilic cells. Intratubular proliferations of atypical cells, paratesticular glandular and/or papillary tumours, or tumours with spindle cell morphology can also be challenging to diagnose correctly. In some problematic cases, immunohistochemical staining may be useful to resolve these differential diagnoses.

Case report: primary carcinoid tumor of the testicle without metastases in combination with testicular atrophy and testosterone deficiency

The first case of testicular carcinoid was represented as an element of a benign cystic teratoma by Simon et al. J Urol 1954; 72: 892-894. It is a rare disease accounting for less than 1% of all testicular neoplasms. We report a case of carcinoid of the testis without carcinoid syndrome and metastasis but with testosterone deficiency based on a bilateral testicular atrophy, which has not been previously reported.

Pure testicular carcinoid associated with intratubular germ cell neoplasia

This case report describes for the first time a case of pure testicular carcinoid pre-aortic lymph node metastases in a 25 year old patient with carcinoid syndrome. The simultaneous occurrence of intratubular germ cell neoplasia in the surrounding testicular tissue was identified by OCT4 and placental-like alkaline phosphatase positivity. This confirmed that the tumour had a germ cell origin in the testis, rather than being a metastasis from an extragenital carcinoid.

Multiple lymph node metastases in a boy with primary testicular carcinoid, despite negative preoperative imaging procedures

A testicular tumor in a 12-year-old boy proved to be a carcinoid tumor. An extensive investigation including a computed tomographic scan of the abdominal and pelvic region as well as both 123I-labeled metaiodobenzylguanidine and 111In-coupled octreotide scintigraphy was normal. Because histopathologic examination of the primary surgical specimen revealed tumor growth in the resection border of the spermatic vessels, a second operation with unilateral lymph node dissection was performed. Surprisingly, 3 lymph node metastases were found. No further treatment was given and the boy is alive without disease 9 years after surgery. This case illustrates that modern scintigraphic techniques do not always detect carcinoid tumors. Because carcinoids respond poorly to other treatment modalities, the importance of initial radical surgery including a meticulous examination of regional lymph nodes is emphasized.

An analysis of rare carcinoid tumors: clarifying these clinical conundrums

Carcinoid tumors are distinct neuroendocrine neoplasms with characteristic histological, clinical, and biological properties. Though commonly associated with the gastrointestinal tract and bronchopulmonary system, a substantial number of these tumors originate in less common anatomical sites and can range from indolent, unrecognized entities to highly active, metastatic secretory tumors. Their presentation within unfamiliar locations often results in clinical confusion, and they persist as unrecognized lesions, subjecting patients to delayed, inappropriate, or ineffective treatment. The authors reviewed 13,715 carcinoid tumors identified by three consecutive registries of the National Cancer Institute (NCI) from 1950 to 1999, focusing on the anatomic sites accounting for less than one percent of all carcinoids. In addition, data from the world's literature published on carcinoid tumors within these particular anatomic locations were then analyzed with respect to incidence, clinical presentation, symptoms, diagnostic evaluation, microscopic and immunohistochemical findings, treatment strategies, and prognosis. The primary organs in which carcinoids are most commonly mistaken for some of the more conspicuous endemic tumors include the esophagus, pancreas, liver, biliary tract, gallbladder, and Meckel's diverticulum, as well as within the pelvic and otolaryngeal organs and the breast. In general, the highest proportion of "rare" carcinoids was identified in the gastrointestinal (GI) tract, with the ovary as the single most affected extra-GI site. Tumors with the worst prognosis were those that involved the pancreas (37.5%: 5-year survival) and those in the cervix (12-33%: 3-year survival). While gastrointestinal carcinoids have become a more recognized entity and thus more amenable to identification, similar lesions are often not considered in other sites and have often either been overlooked or misdiagnosed. Widespread reports of their occurrence in rare locations warrants attention. The diminution of the likelihood of inadvertently neglecting these often benign, indolent neoplasms that are well known to metastasize if unaddressed would represent an important advance. Familiarity with such unusual sites of origin will facilitate appropriate recognition and characterization of such tumors, allowing for timely intervention.

Germ cell tumors of the gonads: a selective review emphasizing problems in differential diagnosis, newly appreciated, and controversial issues

Gonadal germ cell tumors continue to be the cause of diverse, diagnostically challenging issues for the pathologist, and their correct resolution often has major important therapeutic and prognostic implications. They are academically interesting because of the biological diversity exhibited in the two gonads and variation in frequency of certain neoplasms. The most dramatic examples of the latter are the frequency of dermoid cyst in the ovary compared to the testis and the reverse pertaining to embryonal carcinoma. Within the teratoma group, there is strong evidence that ovarian and prepubertal testicular teratomas are derived from benign germ cells, a pathogenesis that likely applies also to the rare dermoid cysts and uncommon epidermoid cysts of the testis. In contrast, postpubertal testicular teratomas derive from malignant germ cells, specifically representing differentiation within a preexistent nonteratomatous cancer. As expected, given the foregoing, teratomas in boys are clinically benign, whereas in postpubertal males they are malignant, independent of their degree of immaturity. On the other hand, immaturity is an important finding in ovarian teratomas, irrespective of age, although its significance in children has recently been challenged. It is usually recognized on the basis of embryonic-appearing neuroepithelium, which shows mitotic activity and apoptosis in contrast to differentiated neuroepithelial tissues, which may occur in mature ovarian teratomas. Rarely it is based on the presence of cellular, mitotically active glial tissue. Fetal-type tissues alone are not sufficient for a diagnosis of immature teratoma. Further differences between the teratomatous tumors in the two gonads are the relative frequency of monodermal teratomas in the ovary in contrast to the testis, where only one subset, carcinoids, is seen with any frequency. When uncommon somatic-type malignancies (usually squamous cell carcinoma) occur in mature cystic teratomas of the ovary, this is a de novo form of malignant transformation; similar tumors in the testis, a very rare event, represent overgrowth of teratomatous elements that originated from malignant, nonteratomatous germ cell tumors and, therefore, had previously undergone malignant transformation. Germinomas may have several unusual features in each gonad; these include microcystic arrangements that suggest yolk sac tumor, tubular patterns that mimic Sertoli cell tumor, apparent increased cytological atypia that causes concern for embryonal carcinoma, and prominent syncytiotrophoblast giant cells that suggest choriocarcinoma. Awareness of these variants, good technical preparations, the retained typical cytological features of germinoma cells, and the judicious use of tailored panels of immunohistochemical stains resolve these dilemmas in virtually all instances. Two aspects of germinomas are unique to the testis. Firstly, intertubular growth of small seminomas may cause them to be overlooked. Secondly, the distinctive spermatocytic seminoma occurs only in the testis. A newly recognized aspect of this tumor is the propensity for some to be relatively monomorphic, making them apt to be mistaken for usual seminoma or embryonal carcinoma, although the characteristic polymorphic appearance in some foci, absence of intratubular germ cell neoplasia, unclassified type, and immunohistochemical stains should prevent this error. Cytoplasmic membrane immunoreactivity for placental alkaline phosphatase and CD117, with usual negativity for AE1/AE3 cytokeratins, is helpful in the diagnosis of germinoma. The recently described marker, OCT3/4, a nuclear transcription factor, is especially helpful in the differential of germinoma and embryonal carcinoma with other neoplasms. Yolk sac tumor continues to be confused occasionally with clear cell carcinoma of the ovary. Glandular ('endometrioid-like') yolk sac tumors mimic endometrioid carcinomas; predominant or pure hepatoid yolk sac tumors cause concern for metastatic hepatocellular carcinoma or, in the ovary, primary hepatoid carcinoma, and solid patterns, especially in limited samplings, may be misinterpreted as germinoma. The usually younger age of patients with yolk sac tumors helps with the differential considerations with the nongerm cell tumors, as do other clinical and microscopic features and selected immunohistochemical stains. Choriocarcinoma is rare in both gonads, and those in the ovary must be distinguished from metastatic tumors of placental origin. Syncytiotrophoblast cells alone, admixed with other forms of germ cell tumor, still are confused with choriocarcinoma, but this phenomenon, which is much more frequent than choriocarcinoma, lacks the plexiform arrangement of different trophoblast cell types that typifies the latter. Mixed germ cell tumors (which may show almost any combination of components) are common in the testis but rare in the ovary. A separately categorized, rare form of mixed germ cell tumor seen in both gonads is the polyembryoma. It is perhaps the most photogenic of all gonadal germ cell tumors and is also intriguing because of its distinctive, organized arrangement of yolk sac tumor and embryonal carcinoma elements and recapitulation of very early embryonic development, even to the extent of having in its fundamental unit, the embryoid body, a miniature yolk sac, and amniotic cavity. These tumors, which are constituted by innumerable embryoid bodies, almost always contain teratomatous glands in minor amounts, and one way of viewing the polyembryoma is to consider it the most immature form of teratoma. Embryoid bodies are also common as a minor component of many mixed germ cell tumors, particularly in the testis, and the diffuse embryoma is another variant that has a particular arrangement of yolk sac tumor and embryonal carcinoma elements. Regression of gonadal germ cell tumors is a phenomenon restricted to the testis, for unknown reasons. These so-called 'burnt-out' germ cell tumors can be recognized by a distinctive constellation of findings, including sometimes minor foci of residual recognizable germ cell neoplasia, a well-defined zone of scarring (often having residual ghost tubules), associated lymphoplasmacytic infiltrate, intratubular calcification and, in about 50%, of in situ germ cell neoplasia.

Primary carcinoid tumor of the testis with teratoma metastatic to the para-aortic lymph node

A primary testicular carcinoid tumor with teratoma metastasized to the para-aortic lymph node. After inguinal orchiectomy, serum and urinary levels of 5-hydroxyindoleacetic acid (5-HIAA) were found to be elevated. Chemotherapy consisting of cisplatin, etoposide and bleomycin was not effective on the metastatic lesions. Retroperitoneal lymphadenectomy normalized the levels of 5-HIAA. The patient is alive without recurrence 25 months after the retroperitoneal lymphadenectomy.

Bilateral asynchronous metastatic carcinoid tumor of the testis

Carcinoid tumor of the testis represents only 0.23% of all testicular malignancies. We report the first case of bilateral asynchronous carcinoid tumor of the testis with a primary site in the small bowel. A 49-year-old man presented with several months of painless enlargement of the left testis. Orchiectomy revealed carcinoid tumor. The patient presented to the emergency room 2 weeks later and was found to have small bowel obstruction due to an ileal mass. The resected mass was the primary source of the carcinoid tumor. Four years later, examination revealed carcinoid tumor in his remaining testis.

Primary carcinoid tumor of the bilateral testis associated with carcinoid syndrome

Carcinoid tumors derived from neuroendocrine cells can release serotonin and other vasoactive substances into the systemic circulation, resulting in carcinoid syndrome. Testicular carcinoid, a rare disease accounting for less than 1% of all testicular neoplasms, rarely manifests symptoms of carcinoid syndrome. We describe a case of carcinoid syndrome arising from a primary testicular carcinoid tumor. A 21-year-old male patient presented with facial flushing and diarrhea for 5 years. He had an enlarged left testis and a 1-cm, ill-defined, hard, non-tender mass in his right testis. His 24 h urinary excretion of 5-hydroxyindoleacetic acid was elevated (16.1 mg/day). Somatostatin receptor scintigraphy correlated with carcinoid tumor in both testes. Following bilateral orchiectomy, the patient's facial flushing and diarrhea disappeared.

Primary carcinoid tumor of the testis: Immunohistochemical, ultrastructural and FISH analysis with review of the literature

Primary carcinoid tumor of the testis only accounts for 0.2% of all carcinoid tumors in Japan. The clinicopathological features, including differences between Japanese and Europe/United States (Eur/US) series', which are known in ovarian carcinoids, have not yet been sufficiently recognized. In the present study, five testicular carcinoids from various clinicopathological viewpoints were analyzed, with a review of the literature. All 15 cases in Japan, including 10 previously reported, were insular carcinoids. Three of the 15 cases (20%) were associated with a teratoma. Serotonin production was confirmed in at least 10 cases (five cases in the present study and five cases in previous studies), but carcinoid syndrome was present in only two cases. Three of the 15 cases (20%) showed distant metastases, and the tumors that metastasized were larger than those that did not. These features were almost similar to those observed in the Eur/US series. Three pure carcinoids were also studied for the number of sex chromosomes by fluorescence in situ hybridization (FISH). They did not show a significant numerical abnormality of the X chromosome, which is common in testicular germ cell tumors. Therefore, the genetic background of pure carcinoids might be different from that of common germ cell tumors.

Primary carcinoid of the testis associated with carcinoid syndrome

Testicular carcinoid is a rare disease accounting for less than 1% of all testicular neoplasms. It rarely manifests symptoms of carcinoid syndrome. Recent reports have noted that only 1.1-3.1% of testicular carcinoid tumors are complicated by carcinoid syndrome. In general, large tumor size and the presence of carcinoid syndrome are features associated with a malignant course. In the present case, pathological findings revealed pure carcinoid of the testis without metastasis. Moreover, watery diarrhea due to carcinoid syndrome disappeared and the serum serotonin level normalized following orchiectomy. The patient was followed up for 12 months with whole body computed tomography scan and assessment of serotonin levels. To date, there is no evidence of tumor recurrence. These findings suggest that monitoring serum serotonin levels may be useful as a marker during follow up of this type of tumor.

Primary hepatic carcinoid and neuroendocrine carcinoma: clinicopathological and immunohistochemical study of five cases

Primary hepatic carcinoid and neuroendocrine carcinoma (NEC) are rare tumors. We experienced three carcinoids and two NEC originating in the liver during the past 25 years and attempted to elucidate the clinicopathological and immunohistochemical features of these tumors. The patients had no endocrine symptoms despite two of them having elevated plasma serotonin. Three of the five patients died of the tumor after operation with an average survival time of 20.6 months. All tumors were large (up to 26 cm in diameter), four of them solitary and one multinodular, and were not associated with liver cirrhosis. The carcinoid tumors showed insular, trabecular or glandular arrangement of argyrophilic cells, whereas in the NEC this histological pattern was distorted. Immunohistochemically the tumors showed expression of chromogranin A (all cases), chromogranin B (three cases), pancreastatin and chromostatin (four cases, respectively), prohormone convertase PC3 (three cases), carcinoembryonic antigen (CEA) and CA19-9 (two cases), cytokeratin 56 kDa (three cases), 160 kDa neurofilament (two cases) and neuron-specific enolase (two cases). Serotonin and glucagon were sporadically detected in two tumors. The most useful marker to confirm the diagnosis was chromogranin A, which was cleaved to pancreastatin and chromostatin in the tumor tissue, and was more reliable than other markers of neuroendocrine differentiation.

Sertoli cell tumors of the testis, not otherwise specified: a clinicopathologic analysis of 60 cases

Sixty Sertoli cell tumors of the testis, excluding large cell calcifying and sclerosing subtypes, are described. Patient age ranged from 15 to 80 years (mean, 45 years). The initial manifestation was usually a testicular mass; in 14 cases it had been enlarging slowly for a period of up to 14 years (mean 3.7 years). Only five patients had testicular pain. Four patients had metastatic disease at the time of presentation. All the tumors were unilateral and ranged from 0.3 cm to 15 cm (mean 3.6 cm). They were typically well circumscribed. Sectioning usually disclosed firm, tan-gray, white, or yellow tissue with areas of hemorrhage and a minor cystic component in approximately one third. Microscopic evaluation usually revealed diffuse sheets or large, nodular aggregates of tumor cells, within which solid or hollow, sometimes dilated, tubules and, less often, cords were usually at least focally identifiable. A relatively acellular, often vascular, fibrous to hyalinized stroma was frequently conspicuous. The tumor cells typically had moderate amounts of pale to lightly eosinophilic cytoplasm, but 10 tumors had cells with abundant eosinophilic cytoplasm. Large cytoplasmic vacuoles were prominent in 26 tumors. Nuclear atypicality was absent or mild in 54 cases, moderate in 4 cases, and marked in 2 cases. Mitotic rate ranged from less than 1 to 21 per 10 high power fields, with 50 tumors having no or only rare mitoses. Vascular space invasion was present in 11 cases and was prominent in 8. Follow-up of more than five years (average 8.4 years), or until evidence of metastasis was seen, was available for 16 patients. Nine were alive and well with no evidence of disease. Four were alive with disease and three died of disease. The pathologic features that best correlated with a clinically malignant course were as follows: a tumor diameter of 5.0 cm or greater, necrosis, moderate to severe nuclear atypia, vascular invasion and a mitotic rate of more than 5 mitoses per 10 high power fields. Only one of nine benign tumors for which follow-up data of 5 years or more were available had more than one of these features, whereas five of seven malignant tumors had at least three.

Primary carcinoid tumour with ossification masquerading as calyx stone in a horseshoe kidney

A case of renal carcinoid tumour arising within a teratoma in a horseshoe kidney in a 23-year-old male is reported. The presenting symptom was abdominal pain, and bone tissue within the tumour was initially misinterpreted as a calyx stone, leading to unsuccessful attempts at extracorporeal shock-wave lithotripsia and percutaneous lithotripsia. This unusual tumour is over-represented in patients with horseshoe kidney and other congenital developmental renal defects.

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.

Primary carcinoid tumor of testis. Immunohistochemical, ultrastructural, and DNA flow cytometric study of three cases with a review of the literature

The cases of three patients with primary carcinoid tumor of the testis were reported. The patients were 41, 44, and 83 years of age. At initial examination, all three had testicular masses with or without associated pain, and none had the carcinoid syndrome. The tumors measured 4.3 cm, 3.0 cm, and 6.5 cm in dimension. All three tumors manifested classic histologic features of carcinoid tumors. The neoplastic cells exhibited argyrophilia, and all were immunoreactive to chromogranin, serotonin, neuron-specific enolase, and cytokeratin. Two tumors had positive test results for gastrin and one had positive test results for substance P and vasoactive intestinal polypeptide. No tumors reacted with somatostatin, insulin, pancreatic polypeptide, or placental alkaline phosphatase. Intracytoplasmic, membrane-bound, round-to-elliptical pleomorphic granules were identified by ultrastructural analysis in all cases. DNA flow cytometric analysis revealed a low degree (near-diploid) DNA aneuploidy in all cases, with a DNA index of 1.15 in two tumors and 1.3 in the third tumor. The three patients are alive and well 11 years, 7 years, and 6 months, respectively, after diagnosis. A total of 57 cases of this entity, including the 3 reported here, have been reported. Of these, 43 were pure carcinoid, and 14 were associated with teratoma; 6 (11.6%) patients developed metastases. Tumor size and the presence of carcinoid syndrome have been found to correlate with metastatic potential. Neither tumor necrosis nor local tumor invasion (into vessels, tunica albuginea, etc.) correlated with adverse prognosis. Carcinoid tumor of the testis is a rare indolent neoplasm with potential for distant metastases.

Case report: primary carcinoid tumour of the testis--ultrasound appearances

Primary carcinoid tumour of the testis is extremely rare. We describe a case of testicular carcinoid, discuss the ultrasound appearances and differential diagnosis.

Primary carcinoid tumor of the testicle: a case report and management schema

A case of primary testicular carcinoid is presented in which extensive testing for peptide hormones was done. None was found suggesting that such tumors may be nonfunctional. A systematic approach to the evaluation and treatment of testicular carcinoid is presented.

Non-germ cell tumors of testis

Testicular tumors of non-germ cell origin represent from 5 percent to 10 percent of all testicular neoplasms. Included in this group are sex cord/gonadal stromal tumors, most originating from Leydig or Sertoli cells, mixed tumors, and tumors of mesenchymal or hematopoietic origin. In addition, various miscellaneous lesions, tumor-like conditions, and secondary testicular tumors may be classified as non-germ cell tumors. This review covers the presentation, diagnosis, and treatment of these rare lesions.

Carcinoid tumor occurring in a mature testicular teratoma

A rare case of a primary testicular carcinoid tumor, occurring in a mature teratoma from a 33 year old man, was examined histochemically, immunohistochemically and by electron microscopy. Both argyrophil and argentaffin reactions were positive. Immunoreactive cells for 5-hydroxytryptamine (5-HT) and gastrin were present. Electron microscopy demonstrated neurosecretory-type granules. The English literature was reviewed and this revealed at least 6 similar cases.

Primary carcinoid tumor of the testis

Primary carcinoid tumors of the testis are exceedingly rare. Thirty-one primary tumors have been reported in the literature, none of which have been diagnosed preoperatively. We present a case report demonstrating the sonographic features of a testicular carcinoid which may contribute to an early preoperative diagnosis.

Pure primary testicular carcinoid: a case report and discussion

We report a case of pure primary testicular carcinoid tumor and review the literature. Distinctions are emphasized among the 3 subgroups of testicular carcinoids and their clinical significance. Criteria to establish the diagnosis of pure primary testicular carcinoid are offered.

Carcinoid tumor of undescended testis

Carcinoid tumor of the testis is rare and its histogenesis is controversial. We report a case of carcinoid tumor in an undescended testis with electron microscopic evidence of neurosecretory granules.

Primary neuroectodermal tumour of the testis

A 51-year-old male presented with metastasis of a small cell carcinoma of unknown origin in a right inguinal lymph node. Clinical and laboratory studies failed to locate the primary tumour. After three years, a swelling appeared in the right testis, which was removed. Histological examination revealed a proliferation of small tumour cells forming irregular masses or nests that occupied most of the testicular parenchyma. At the periphery of the testicular parenchyma a few seminiferous tubules could be observed, showing a low and incomplete seminiferous epithelium and numerous tumour cells in the lumen. Most of the tumour cells showed a euchromatic nucleus with small nucleoli and scanty cytoplasm. Among these cells, larger binucleate or trinucleate cells as well as small cells with pyknotic nuclei were also observed. Mitoses were numerous. Electron microscopy revealed some tumour cells with 80 to 100 nm vesicles containing electron-dense granules. Some cells displayed dendrite-like prolongations with numerous intermediate filaments and electron-dense vesicles. This tumour is compatible with a primary neuroectodermal tumour of the testis.

Primary carcinoid tumor of testis with metastasis

A primary carcinoid tumor of the testis metastatic to one preaortic lymph node in a forty-three-year-old man is reported. The case was of great clinical interest not only because of the extreme rarity of testicular carcinoid with metastasis but also because of a coincidental bacterial endocarditis.