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Keywords:

  • carcinoid syndrome;
  • carcinoid tumor;
  • testicular tumor

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case report
  5. Discussion
  6. References

Abstract 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.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case report
  5. Discussion
  6. References

Testicular carcinoid is a rare disease accounting for less than 1% of all testicular neoplasms.1 It rarely manifests symptoms of carcinoid syndrome (diarrhea, flushing and bronchospasm).1,2 Recent reports have noted that only 1.1–3.1% of testicular carcinoid tumors are complicated by carcinoid syndrome.1–3 In general, tumor size2 and the presence of carcinoid syndrome are features associated with a malignant course.4–6 We report a case of carcinoid of the testis associated with carcinoid syndrome without metastasis.

Case report

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case report
  5. Discussion
  6. References

A 41-year-old man presented with a painless, gradually enlarging right testicular mass that he had been aware of for 1 year. He complained of watery diarrhea and dull right testicular pain that had persisted for 6 months before hospitalization. Physical examination revealed that the right testis had a palpable stony hard mass. Scrotal ultrasonography detected a right solid testicular mass that had almost completely replaced the normal tissue. Serum testicular tumor markers such as α-fetoprotein, human chorionic gonadotrophin-β and lactate dehydrogenase were all normal. Computed tomography scans of the chest, abdomen and pelvis were negative.

A right high inguinal orchiectomy was performed for diagnosis. The testis had been replaced by a 6.4 × 5.1 × 2.6 cm homogenous yellowish tumor that weighed 79 g. Pathological findings revealed that the tumor was composed of nests and acini of uniform cells with central hyperchromatic nuclei. The cell body was acidophilic (Fig. 1a). Grimelius stain detected argyrophilic granules throughout the cytoplasm of the tumor cells (Fig. 1b). Immunohistochemical staining demonstrated that the granules contained positively stained chromogranin A (Fig. 1c). Argentaffin-positive granules were also demonstrated by using Fontana–Masson stain. Transmission electron microscopy of formalin-fixed tissue revealed pleomorphic neurosecretory-type granules. These dense-core granules, which ranged in size from 200 to 300 nm were present in the cytosol, especially under the plasma membrane (Fig. 2). The findings supported the diagnosis of typical pure testicular carcinoid of midgut derivation.

image

Figure 1. (a) Solid cell nests separated by a fine vascular stroma. Small and large nests composed of regular epithelial cells were occasionally elongated or cylindrical, forming acini, palisaded or granular and tubular arrangements (original magnification × 100; H&E). (b) Argyrophil reaction of testicular carcinoid. The argyrophilic granules throughout the cytoplasm of the tumor cells (original magnification × 200; Grimelius stain). (c) The tumor cells are strongly positive for chromogranin A (original magnification × 200).

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image

Figure 2. Transmission electron microscopy performed on formalin-fixed tissue revealed pleomorphic neurosecretory-type granules. These dense-core granules, which ranged in size from 200 to 300 nm (original magnification × 4000), were present in the cytosol, especially under the plasma membrane.

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The watery diarrhea disappeared after the orchiectomy. On the seventh postoperative day, serum serotonin levels were still elevated at 454 ng/mL (normal: 57–230 ng/mL). However, serotonin levels normalized within 3 weeks and postoperative findings on upper gastrointestinal and small intestinal series and a barium enema were all normal. 125I meta-iodobenzyl guanidine (MIBG) scintigraphy was negative. There was no evidence of other primary foci or metastases. The patient was followed up for 12 months with whole body CT scan and assessment of serotonin levels.

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case report
  5. Discussion
  6. References

Testicular carcinoid is a rare disease that accounts for less than 1% of all testicular neoplasms.1 The most important differential diagnosis of a primary testicular carcinoid, both histologically and clinically, is metastatic carcinoid tumor. This possibility can be easily excluded in cases where the carcinoid is associated with a teratoma but is much more difficult to exclude when the carcinoid is in its pure form, which is the most common type of primary testicular carcinoid.3 In the present case, the findings of both hematoxylin and eosin and immunohistochemical staining revealed pure testicular carcinoid. To assess the origin of the carcinoid tumor, both Grimelius and Fontana–Masson stains were performed. The histochemical findings of our case suggest this testicular carcinoid originated in the midgut.1 Moreover, scanning electron microscopy confirmed that this tumor was part of the amine precursor uptake and decarboxylation (APUD) system described by Pearse et al.7 When occurring within a teratoma, such carcinoids are usually seen in association with the gastrointestinal or respiratory epithelium and may form only a minor component of a teratoma.1–3 Careful assessment is needed to exclude the presence of other neoplastic germ cell elements within the tumor. In general, primary testicular carcinoids have an excellent prognosis but there are few reports of metastasis. According to recent reports, the overall incidence of metastasis is about 11%.4–6 Tumors that metastasize tend to be larger (mean: 7.3 cm) than those that do not (mean: 2.9 cm).2

The elevation of urinary 5-hydroxyindoleacetic acid (5-HIAA) and serum serotonin levels following orchiectomy often suggests the possibility of a metastatic tumor.3,8,9 However, it rarely manifests symptoms of carcinoid syndrome (diarrhea, flushing and bronchospasm).1,2 Recent reports have noted that only 1.1–3.1% of testicular carcinoid tumors are complicated by carcinoid syndrome.1–3 In the present case, watery diarrhea due to carcinoid syndrome disappeared following orchiectomy. Moreover, the serum serotonin level normalized after surgery. Perhaps monitoring serum serotonin levels would be a useful marker to detect recurrence in this case. In the pure form of testicular carcinoid without metastasis, no further therapy is considered necessary following orchiectomy. Chemotherapy for local or metastatic carcinoid has shown little or no benefit.10 Hosking et al. reported a case of metastatic lesion and carcinoid syndrome 17 years after removal of the primary carcinoid tumor.4 Long-term follow up evaluation is clearly indicated for patients with this type of neoplasm.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case report
  5. Discussion
  6. References
  • 1
    Berdjis CC & Mostofi FK. Carcinoid tumors of the testis. J. Urol. 1977; 118: 77782.
  • 2
    Zavala-Pompa A, Ro JY, El-Naggar A et al. Primary carcinoid tumor of testis. Immunohistochemical, ultrastructural, and DNA flow cytometric study of three cases with a review of the literature. Cancer 1993; 72: 172632.
  • 3
    Talerman A, Gratama S, Miranda S, Okagaki T. Primary carcinoid tumour of the testis: Ultrastructure and review of the literature. Cancer 1978; 42: 2696706.
  • 4
    Hosking DH, Bowman DM, McMorris SL, Ramsey EW. Primary carcinoid of the testis with metastasis. J. Urol. 1981; 125: 2556.
  • 5
    Sullivan JL, Packer JT, Bryant M. Primary malignant carcinoid of the testis. Arch. Pathol. Lab. Med. 1981; 105: 5157.
  • 6
    Kaufman JJ & Waisman J. Primary carcinoid tumor of testis with metastasis. Urology 1985; 25: 53436.
  • 7
    Pearse AGE & Polak JM. Endocrine tumours of neural crest origin: Neurolophomas, apudomas and the APUD concept. Med. Biol. 1974; 52: 318.
  • 8
    Glazier DB, Murphy DP, Barnard N, Cummings KB, Weiss RE. Primary carcinoid tumour of the testis. BJU Int. 1999; 83: 1534.
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  • 9
    Sutherland RS, Wettlaufer JN, Miller GJ. Primary carcinoid tumor of the testicle: A case report and management schema. J. Urol. 1992; 148: 88082.
  • 10
    Moertel CG & Hanley JA. Combination chemotherapy trials in metastatic carcinoid tumor and the malignant syndrome. Cancer Clin. Trials 1979; 2: 32734.