Primary carcinoid tumor of the testis: case report, ultrastructure and review of the literature

Neuroendocrine tumours in rare sites: differences in nomenclature and diagnostics-a rare and ubiquitous histotype

The diagnosis of neuroendocrine tumours in typical sites, as gastrointestinal tract and lung, is based upon well-coded criteria that have become familiar to most of the pathologists. Much more difficult is the recognition and allocation of proper nomenclature to be referred to the same histotype in locations where these tumours have a lower incidence. The aim of our review was to provide a quick handbook of the main diagnostic pitfalls known in literature that can interpose in the histopathological examination of neuroendocrine tumours in rare sites (urinary system and male genital organs, female genital organs, head and neck and breast).

Primary pure carcinoid tumors of the testis: Clinicopathological and immunophenotypical characteristics of 11 cases

Primary pure carcinoid tumors of the testis (pPCTT) are rare, and there are only a limited number of studies available. In the present study we described the clinicopathological and immunophenotypical characteristics of 11 cases from our institution between 1978 and 2014, and reported our experiences of the diagnosis and treatment of these patients. The patients ranged in age from 26 to 68 years old, with a median age of 48 years. One patient (9%) was classified as pT2 and 10 (91%) were pT1. Histologically, 7 cases were diagnosed as classical carcinoid tumors, while the other 4 cases were identified as atypical carcinoid tumors. The most common growth pattern was a mixed insular, acinar, rosetted, solid and trabecular pattern. Immunohistochemical staining revealed positive expression of neuron-specific enolase in all cases, and CgA, Syn and CD56 markers in 8 (72.7%), 10 (90.9%) and 9 cases (81.7%), respectively. In addition to radical orchiectomy, 9 patients (81.7%) received a combined modality of treatment. Follow-up data were available for 8 patients. Seven were alive at the last follow-up without recurrence, and one patient succumbed to cerebral hemorrhage 7 years after surgery. In summary, localized pPCTT is a rare disease with an indolent clinical course. When a testicular carcinoid tumor is identified, a metastasis or an intestinal primary tumor should be excluded, particularly when the testicular tumor is large. A tumor size ≤6.0 cm and the histological appearance had little relation with metastatic behavior.

Primary neuroendocrine tumor of the testis

Testicular neuroendocrine tumor is rare. It accounts for less than 1% of all testicular neoplasms. More than 60 cases have been published in the literature. A 27-year-old man presented with left testicular mass and underwent radical orchidectomy. Histological examination showed neuroendocrine tumor, confirmed by immunohistochemistry and electron microscopy. The patient showed no evidence of metastasis over 1-year follow-up post-orchidectomy in spite of extensive tumor necrosis.

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.

Immunohistochemical analysis of neuroendocrine (NE) differentiation in testicular germ cell tumors (GCTs): use of confocal laser scanning microscopy (CLSM) to demonstrate direct NE differentiation from GCTs

Neuroendocrine (NE) differentiation is infrequent in testicular tumors and its histogenesis is not well understood. The present study is aimed at elucidating the pathway of neuroendocrine differentiation in germ cell tumors (GCTs) of the testis. In the analysis of 46 germ cell tumor components from 23 testicular tumors, we focused on GCTs with neuroendocrine differentiation, 7 teratoma, 1 embryonal carcinoma and 1 neuroendocrine carcinoma by immunohistochemical study and confocal laser scanning microscopy (CLSM) analysis. NE marker positive cells were noted in the tumor with collision of teratoma and embryonal carcinoma (E&T tumor), in the immature columnar cells of transitional form of embryonal carcinoma to teratoma (E-T cells) and neuroendocrine carcinoma cells, in addition to the well known mature intestinal mucosa in teratoma. Double staining for a NE marker (CGA) and a germ cell marker (PLAP) demonstrated the localization of both proteins in the same E-T cells confirmed by CLSM. Another finding, indicating the intimate relation between embryonal carcinoma and neuroendcrine differentiation, is that neuroendocrine carcinoma expressed a marker of embryonal carcinoma, CD30. The present results indicated that the NE cells might be differentiated from embryonal carcinoma, a view that has not been proposed before, but that is made in the present study using CLSM.

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.

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.

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.

Testicular metastasis of primary cecal carcinoid tumor

Testicular carcinoids are rare and the majority are of primary testicular origin. Testicular carcinoids can also be secondary from extra-testicular primary tumors, but the incidence is even less common. The case described here is a patient who initially had an infiltrating cecal carcinoid with hepatic metastasis. Following surgery, he was managed with octreotide and had close monitoring of the levels of serum serotonin and its urinary metabolite. He experienced a fairly indolent clinical course and 5 years after excision of the primary cecal carcinoid, his hepatic lesion has virtually been unchanged. However, he developed a secondary testicular metastasis. He has otherwise remained well, without evidence of metastases elsewhere on imaging studies.

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 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.

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.

Cellular junctions in a spectrum of human malignant tumors

Cellular junctions in tumors are often considered a hallmark of epithelial differentiation. However, junctions are also seen in tumors having a different differentiation. This observation prompted us to study cellular junctions in malignant nonepithelial tumors. We found a variety of cellular junctions in such tumors, although the majority were poorly formed. This observation is of importance for diagnostic purposes. We have also tried to clarify the nomenclature of cellular junctions as applied in tumor diagnosis by proposing a systematic categorization of terms in everyday use by pathologists and by referring more extensively to the term paired subplasmalemmal densities (PSD) for non-well-formed junctions.

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.

Testicular neuroblastoma

We describe, in a young boy, a case of neuroblastoma presenting only as a painless unilateral testicular mass. Clinical and laboratory evidence of disseminated neuroblastoma was first apparent nine months after high orchiectomy. As far as we are aware this is the only reported instance of testicular neuroblastoma in the absence of disseminated disease. Discussion is directed to the possible explanations for this rare testicular lesion, and in addition, underlines the potential difficulties in the diagnosis of certain small cell tumors.

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.

Cervical metastases from small bowel carcinoid tumors

Small bowel carcinoid tumors usually metastasize to regional lymph nodes and the liver but metastases to the neck are extremely rare. Over a ten-year period 48 cases of small bowel carcinoid were diagnosed at our institution and of these, three cases (6%) were associated with neck metastases--one to the thyroid gland and two to cervical lymph nodes. The former patient and one of the latter patients had symptoms of the carcinoid syndrome. The other patient was asymptomatic and presented with a solitary neck mass. Urine levels of 5-hydroxyindolacetic acid (5-HIAA) were elevated in the two symptomatic patients but were undetectable in the asymptomatic patient. Extirpation of the involved cervical nodes and the primary small bowel lesion was performed in two patients. In addition, both patients have received chemotherapy with 5-fluorouracil. One patient remains asymptomatic four years after diagnosis but the other patient continues to have five to six bowel movements per day nine months after operation. Small bowel resection was performed in the patient with a metastasis to the thyroid. This patient died of sepsis after a second operation for an intraabdominal abscess. The histological patterns of the primary tumor and the metastatic lesions were similar and the cells of the metastases contained argentaffin-positive granules. We conclude that 1) an intraabdominal carcinoid tumor should be considered as the location of the primary tumor in patients who present with a neck mass containing metastatic carcinoid and 2) the prognosis for patients with extraabdominal metastases is similar to that for patients with intraabdominal disease only.

Carcinoid tumors of the eye and orbit: a clinicopathologic study of 15 cases, with histochemical and electron microscopic observations

This clinicopathologic study includes 15 cases of carcinoid tumors of the eye and orbit. The patients ranged in age from 14 to 86 years (median, 53). No prediction for either gender was found. Seven tumors involved the orbit, seven the choroid, and one the iris. The primary site of origin of the carcinoid tumor was known in 12 cases: seven in the bronchus, one in the trachea, and four in the ileum. In three cases an orbital tumor was present but no other known primary neoplasm was clinically apparent. The postoperative follow-up period ranged from 0 to 4 years. The urinary levels of 5-hydroxyindoleacetic acid (5-HIAA) were elevated in four of ten patients tested, each of whom had a known primary tumor and two of whom had clinical evidence of the carcinoid syndrome. Four main histologic patterns were recognized: pattern A (solid lobules or masses), pattern B (trabecular or cord-like), pattern C (tubular or rosette-like) and pattern D (mixed). The apparently primary carcinoid tumors and the orbital or ocular metastases were closely related by their histologic patterns, histochemical staining characteristics, and ultrastructural features.

Canine hepatic carcinoids

In 110 primary hepatic neoplasms in the dog, 15 carcinoids were diagnosed. Diffuse involvement of all liver lobes with severe hemorrhage and necrosis was seen in all cases. The neoplasms had three distinct histologic patterns: solid nests, cords or ribbons; and an alveolar pattern with rosettes. In all three groups there was fibrovascular stroma that was hyalinized, mineralized, and thick in some places. The neoplastic cells were relatively uniform, polygonal to spindle-shaped, with eosinophilic, granular cytoplasm and vesiculated nuclei. Mitotic activity varied among the three groups. Argyrophilia was seen in all specimens stained with modified Grimelius stain. Metastasis occurred in 14 of 15 dogs (93.3%); the peritoneal wall and adjoining lymph nodes were the most common sites.

Cervical carcinoid ("argyrophil cell" carcinoma) associated with an endocervical adenocarcinoma: a light and ultrastructural study

On microscopic examination of a cervical carcinoid removed from a 29-year-old woman, foci of endocervical adenocarcinoma in situ (AIS) and severe squamous dysplasia were present immediately adjacent to the invasive carcinoid tumor. Cells of the carcinoid tumor contained abundant intracytoplasmic argyrophilic granules and numerous neurosecretory granules (NSG) on ultrastructural study. Neoplastic cells of the endocervical AIS were devoid of argyrophilic granules and contained no NSGs. The present neoplastic process appeared similar to cases of a "mixed" type neoplasm composed of a carcinoid tumor and an adenocarcinoma, which have been reported from several areas of the body but only once previously from the cervix. The possible mechanisms accounting for such an unusual neoplastic process are discussed.

Primary carcinoid of the testis with metastases

A case of pure carcinoid of the testis is reported. The patient presented with metastatic carcinoid and the carcinoid syndrome 17 years after removal of the primary tumor. He died 2 years later. The long interval from initial orchiectomy to presentation with metastases strongly suggests that the original lesion was primary rather than metastatic. Only 2 cases have been reported to date in which an apparently pure primary testicular carcinoid developed metastases. In both of these cases the possibility that the testicular lesion itself was metastatic was not excluded.

Endocrine GEP-cells in primary testicular teratoma

Differentiated teratomas frequently contain the apparent equivalent of gastrointestinal mucosa. 53 testicular teratomas were investigated for the incidence of entero-endocrine cells. Enterochromaffin(EC)-cells were demonstrated by formaldehyde induced fluorescence (FIF), while the other endocrine cells were identified by immunohistochemistry. 11 of 53 teratomas contained endocrine cells associated with the gastrointestinal epithelium. The most frequently found cell type was the EC-cell, followed by somatostatin-, glucagon- and pancreatic polypeptide-immunoreactive cells. The teratoma tissue blocks (20 of 53) also frequently exhibited normal testicular tissue which did not contain any EC-cell or other entero-endocrine cells. The results are of interest in considering the cytogenesis of entero-endocrine cells and the histogenesis of testicular carcinoids, indicating that the entero-endocrine cells derive from the intestinal carcinoids, indicating that the entero-endocrine cells derive from the intestinal epithelium arising from undifferentiated stem cells. Furthermore, it seems probable that primary testicular carcinoids can develop from pre-existent teratomas by proliferation of their entero-endocrine cells.