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Departments of Endocrinology and Diabetes (G.P., A.A., N.M., T.K., G.Ka.), Pathology (G.Ko.), and Surgery (K.V.), G. Gennimatas General Hospital, 115 27 Athens, Greece; Department of Pathology and Laboratory Medicine, Mayo Clinic Foundation (R.V.L.), Rochester, Minnesota 55905; and Department of Pathology, St. Michaels Hospital (G.Ko., E.H., K.K.), University of Toronto, Toronto, Ontario, Canada M5B 1W8
Address all correspondence and requests for reprints to: Dr. George P. Piaditis, Department of Endocrinology and Diabetes Center, KOFKA Building, 1st Floor, G. Gennimatas General Hospital of Athens, 154 Messogion Avenue, 115 27 Athens, Greece. E-mail: edk-pgna{at}otenet.gr.
| Abstract |
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| Introduction |
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We report the case of a 33-yr-old woman who presented with symptoms/signs of virilization and bilateral ovarian luteinized granulosa-thecal cell tumors attributed to ectopic LH secretion from a pancreatic endocrine tumor. The progressive severe clinical symptoms and the persistently markedly elevated serum LH levels led to identification of the ectopic LH production source. Clinical and biochemical remission after resection of the tumor and morphological studies conclusively confirmed that the pancreatic tumor was the source of ectopic LH production in this patient. To our knowledge, this rare clinical entity secondary to ectopic production of bioactive LH has never been described.
| Subject and Methods |
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A 33-yr-old woman was referred to G. Gennimatas General Hospital of Athens with rapidly developing symptoms/signs of hyperandrogenism, secondary amenorrhea, infertility, and substantially elevated serum LH levels (220 IU/liter; normal range, 525 IU/liter). Her menarche was at the age of 15 yr; because she subsequently developed oligomenorrhea and mild hirsutism, the diagnosis of PCOS was made. The patient underwent a successful pregnancy and delivery at the age of 22 yr, after 3-month treatment with clomiphene citrate and hCG; her endocrine profile at that time was not available. After delivery, she developed oligomenorrhea again and secondary infertility despite treatment with clomiphene citrate/hCG or gonadotropins/hCG for 4 yr. Two years before admission to our hospital she developed severe acne, deepening of her voice, amenorrhea, and worsening hirsutism. Endocrine investigations revealed high serum androgen [free testosterone (FT), 18.01 pg/ml (62.46 pmol/liter; normal range, 0.73.6 pg/ml);
4-androstenedione (
4A), 13.99 ng/ml (48.87 nmol/liter; normal range, 0.52.8 ng/ml)] and LH (156.5 IU/liter) levels, but normal dehydroepiandrosterone sulfate [DHEA-S; 173.9 µg/dl (4.72 µmol/liter; normal range, 35430 µg/dl)], FSH (5.3 IU/liter; normal range, 18 IU/liter), and prolactin (PRL; 8.4; normal range, <23 ng/ml) levels. Ovarian ultrasonography revealed a 2.8-cm left ovarian solid tumor and slight enlargement of the right ovary. Computer tomography (CT) and magnetic resonance imaging (MRI) of the pituitary did not reveal any pathology. The patient underwent resection of the left ovarian tumor and a wide wedge resection of the right; histology revealed a typical thecoma with nodular hyperthecosis of the resected right ovarian wedge. Postoperatively, androgen serum levels markedly decreased [total testosterone, 0.60 ng/ml (2.1 nmol/liter; normal range, 0.20.9 ng/ml); FT, 2.30 pg/ml (7.98 pmol/liter);
4A, 3.29 ng/ml (11.5 nmol/liter)], but serum LH levels remained markedly elevated at 220 IU/liter. Because pituitary imaging was negative, a presumptive diagnosis of severe PCOS was made, and the patient was started on treatment with a long-acting GnRH analog (triptorelin depot, 3.75 mg/month) for 3 months. This treatment was not associated with any substantial reduction of the elevated LH serum levels (LH, 98220 IU/liter); in addition, serum androgens raised again to the postoperative levels [FT, 17.1621.57 pg/ml (59.574.8 pmol/liter)]. For 4 months before her current admission, she received no medication.
On admission, she was found to be normotensive (125/75 mm Hg), but overweight (body mass index, 27 kg/m2). Clinical examination revealed marked acne on the face and neck, hirsutism, and virilism. Terminal hair was present beneath the chin, on the upper lip, the sideburn area, about the areola, and over the presternal region. The pubic hair extended along the midline to the umbilicus and involved the medial aspects of the thighs. Muscle bulk was increased, and she had mild (grade II) clitoromegaly, but no acanthosis nigricans; the rest of the clinical and gynecological examination showed no abnormalities. Routine hematology and biochemistry were normal. Serum androgen [
4A, 19.98 ng/ml (69.8 nmol/liter); FT, 21.57 pg/ml (74.8 pmol/liter); 17-hydroyprogesterone, 7.92 ng/ml (24 nmol/liter; normal range, 0.11.0 ng/ml)] and LH (203 IU/liter) levels were elevated, whereas estradiol (E2) [92.34 pg/ml (339 pmol/liter)], PRL (10.6 ng/ml), DHEA-S [254 µg/dl (6.9 µmol/liter)], and FSH (3 IU/liter) were within the normal range; SHBG [22.9 nmol/liter; normal range, 20120 nmol/liter) levels were significantly reduced. She underwent an oral glucose tolerance test (75 g glucose, orally), which revealed normal glucose tolerance with mild hyperinsulinemia (insulin: 0 min, 11.3; 30 min, 65.4; 60 min, 101.3; 90 min, 107.1; 120 min, 113.6 µU/ml). Thereafter, the patient received octreotide, a long-acting somatostatin analog (200 µg/6 h for 3 d), which resulted in significant reduction of serum LH levels (before, 220 IU/liter; after, 104 IU/liter).
A repeated MRI scan of the pituitary showed no evidence of a pituitary lesion, and a transvaginal ultrasonographic pelvic examination revealed a normal uterus with an 8-mm endometrium and a 2.2-cm solid tumor of the right ovary. After substantial reduction of serum LH levels following the administration of octreotide, additional imaging with helical CT scan of the chest, CT and MRI of the abdomen, as well as a whole body [111In]octreotide scan (octreoscan) were suggested. However, because of the severity of the symptoms/signs of hyperandrogenism and their apparent relation to the tumor of the ovary, the patient decided to have a right ovariectomy in a private maternity hospital. Histology also disclosed a typical thecoma.
Two months later, the patient was readmitted to this hospital for additional investigation. Although postoperative serum androgen and E2 levels fell within or below the normal range [total testosterone, 0.39 ng/ml (1.38 nmol/liter); FT, 1.5 pg/ml (5.2 pmol/liter);
4A, 0.9 ng/ml (3.14 nmol/liter); E2, 8.17 pg/ml (30 pmol/liter)], serum LH remained grossly elevated (LH, 238.8 IU/liter; FSH, 48.4 IU/liter). Both the CT and MRI scans of the abdomen revealed a 7-cm tumor at the tail of the pancreas (Fig. 1
), which corresponded to a well-demarcated intense uptake of a whole body octreoscan (Fig. 2
); a CT of the adrenals was normal. On view of these findings, a presumptive diagnosis of ectopic LH secretion from a pancreatic endocrine tumor possessing somatostatin receptors was made. The patient underwent surgical exploration and removal of the pancreatic tumor.
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Histology
For light microscopy, formalin-fixed, paraffin-embedded tissue samples were used; sections 4 µm thick were stained with hematoxylin and eosin.
Immunohistochemistry
The standard avidin-biotin-peroxidase complex technique was applied on paraffin sections of the pancreatic tumor. Details of the technique have been previously described (11). Primary antisera included general endocrine markers and related antigens (chromogranin, synaptophysin, neuron-specific enolase, and S-100 protein), endocrine hormones and peptides (insulin, glucagon, somatostatin, pancreatic polypeptide, cholecystokinin, vasoactive intestinal polypeptide, and hCG), and pituitary hormones [GH, PRL, ACTH, ß-TSH, ß-FSH, ß-LH, and
-subunit of glycoprotein hormones (
-SU)]. The proliferation index was estimated using the Ki-67 antibody (cone MIB-1). For the ovarian tumors, immunohistochemistry for
- and ß-inhibin was also used (Table 1
).
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For electron microscopy, selected samples of the pancreatic tumor were appropriately fixed in glutaraldehyde, postfixed in osmium tetroxide and embedded in a mixture of Epon-Araldite. Ultrathin sections, stained with uranyl acetate and lead citrate, were studied with a Phillips 410LS electron microscope (Phillips Electronic Instruments, Rahway, NJ) (11).
In situ hybridization
The technique was performed using sequences of oligonucleotide probes for ß-LH and
-SU as described previously (12, 13, 14). Briefly sections from the pancreatic tumor were deparaffinized, treated with prehybridization washes, and incubated with 1x106 cpm 35S-labeled probes in hybridization buffer for 18 h. They were subsequently washed in 2x and 0.5x standard saline citrate and dehydrated in alcohol. Autoradiography was carried out with Kodak NTB2 emulsion (Eastman Kodak Co., Rochester, NY). After 2 wk, they were developed and counterstained with hematoxylin. Negative controls for in situ hybridization used oligonucleotide and sense probes for ß-LH and
-SU. For positive controls, normal anterior pituitary tissue was used.
Dispersed cell cultures
Pancreatic tumor tissue was mechanically dissected in PBS solution and digested in solution containing DMEM/Hams F-12, collagenase type 2 (1 mg/ml), and gentamicin (100 µg/ml). There were three enzymatic digestions of 30 min each; then the dispersed cells were placed in 24-well plates (100,000 cells/well plate and 200,000 cells/well plate). After incubation at 37.5 C in 5% CO2 for 24 h, cells were treated with somatostatin for 14 h. Consequently, the supernatant was collected, and the LH concentrations were measured and compared with the basal levels of the untreated controls.
Hormone assays
Serum LH, FSH, and hCG concentrations were determined by two-site monoclonal antibody immunoradiometric assays (CIS Bio-International, Saclay, Paris, France), and all other hormones were determined by double antibody RIAs:
4A with Diagnostic System Laboratories kits (Webster, TX); total testosterone with Byk-Sangtec kits (Dietzenbach, Germany); E2, FT, DHEA-S, and insulin with Diagnostic Products Corp. kits (Los Angeles, CA); 17-hydroyprogesterone with a CIS Bio-International kit; and SHBG with an Orion Diagnostica kit (Espoo, Finland). The LH assay showed no cross-reaction with hCG, FSH, TSH, or
- and ß-LH subunits.
| Results |
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Histology.
The pancreatic tumor admitted for histology was ovoid, well demarcated, and encapsulated, measuring 6.5 x 4.5 x 4.5 cm. On sectioning, it was solid, soft, and yellow, showing a homogeneous, partly lobular appearance. Histological examination was consistent with the diagnosis of a well-differentiated pancreatic endocrine tumor. The tumor consisted of highly cellular solid nests or anastomosing trabecules, separated by delicate, vascularized connecting tissue (Fig. 3
). The tumor cells were small and round with spherical nucleus and focally conspicuous nucleolus. Mitotic figures were rare.
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-SU (Fig. 4
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-SU mRNA antisense probes, whereas the sense probes produced no staining (Fig. 6
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Histological and immunohistochemical analysis.
By light microscopy, the ovarian tumors were composed of clusters or sheets of ovoid or polyhedral cells with ample acidophilic cytoplasm and discerning cytoplasmic borders. The nuclei were small and round, possessing small nucleoli. Among the tumor cells, eosinophilic proteinaceous material was focally present. By immunohistochemistry, the tumor cells were selectively positive for
- and ß-inhibin, showing strong and diffuse cytoplasmic reactivity. The adjacent parenchyma of both ovaries included multiple atretic cystic follicles, showing luteinization of the inner theca; some of them were in various stages of regression. In addition, multiple primary ovarian follicles were noted. The initially resected right ovarian wedge also showed foci of nodular hyperthecosis. Based on the histological findings, the diagnosis of luteinized granulosa-thecal cell tumor was made.
| Discussion |
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Cushings syndrome may be caused by ACTH (15) or CRH (3), and acromegaly is GHRH mediated in most cases (4, 16), whereas ectopic GH secretion is rarely observed (17). Less commonly secreted peptide hormones have also been noted, including PTH-like peptide (5), calcitonin (18, 19), calcitonin gene-related peptide (20), proopiomelanocortin-derived peptides (21), neuropeptide Y (22), and ghrelin (23). In some cases, hormone precursors are produced and secreted by the pancreatic tumors instead of the intact hormone, whereas the excessive production of many of these hormones may not be associated with characteristic signs and symptoms.
Until recently, only one case of pancreatic endocrine tumor with ectopic LH production has been reported in a 40-yr-old woman (24). Although this woman was of reproductive age, there was no hirsutism or acne, and her serum levels of all androgens were within the normal range, in contrast with our case, in whom severe hirsutism and greatly elevated serum androgens levels were observed. The findings in the previously reported case suggest that either the LH molecules secreted by the tumor were not bioactive or the LH receptors were desensitized by the greatly elevated LH levels (644 IU/liter). The latter explanation seems more likely, because the LH secreted by the tumor was shown to be bioactive using a heterologous bioassay. It is probable that when extremely elevated LH levels exceed a critical level, they can induce LH receptor desensitization. However, this may not be the case in our patient, partly because of the much lower LH levels (203 IU/liter). Although LH receptor desensitization is a well-characterized phenomenon after prolonged elevation of hCG/LH levels (25), this is not always the case, because men with an hCG-producing tumor and greatly elevated serum hCG levels (>3.5 x 103 IU/liter) retain serum testosterone levels well above the normal range (26). In addition, long-standing elevation of LH levels in transgenic mice was associated with hyperandrogenemia and thecal-interstitial cell hypertrophy (27), whereas complete desensitization of the LH receptor is not observed even after the administration of high LH or CG doses in different animal models (28).
The findings in our case are in agreement with the above observations and show that the human ovaries may retain a significant steroidogenic activity, besides chronically and greatly elevated LH levels. This may be related to the gradual and progressive increase in LH production defined by the benign nature and slow growth potential of the tumor. At the early stages of LH tumor development, LH levels rise but still remain below a critical level, capable of inducing receptor desensitization, retaining full biological activity capable of inducing profound proliferation and luteinization of ovarian stromal cells. Thereafter, as the LH tumor size increases, the LH concentration exceeds that critical level and may thus cause LH receptor desensitization. However, as mentioned above, LH receptor desensitization is not complete, and the remaining, even small, LH bioactivity may justify the significantly raised ovarian androgen levels because of the preceding ovarian stromal cells hyperplasia (mass effect). Nevertheless, ectopic bioactive LH production causing ovarian hyperthecosis and bilateral thecomas has not been reported to date.
The present case offers a unique opportunity to investigate the effect of long-standing, elevated, ectopically produced bioactive LH by a pancreatic endocrine tumor on ovarian function and histology in a woman of reproductive age. Ectopic secretion of bioactive hCG is a strong stimulus of ovarian or testicular steroidogenesis (6, 7, 8). The same holds true for ectopic secretion of bioactive LH, which was confirmed in our case by the clinical picture and significantly elevated serum androgen levels. Excessive LH production by the pancreatic tumor was documented by the increased serum and cell culture medium LH levels measured by an assay specific for LH (immunoradiometric assay) as well as by immunohistochemical analysis and in situ hybridization. In addition, electron microscopic studies confirmed the presence of secretory granules in the cytoplasm of pancreatic tumor cells. The positive octreoscan as well as the somatostatin-induced reduction of LH secretion in vivo and in vitro provided evidence that functional somatostatin receptors were present in the tumor cells, a common finding in endocrine tumors. Thus, scintigraphy with [111In]octreotide should be recommended when the suspicion of an ectopic source arises, because many endocrine tumors have somatostatin receptors and can be identified by a positive scan (29).
Two other cases of ectopic bioactive LH secretion, both by adrenocortical tumors, causing precocious puberty and increased LH and testosterone levels in two young boys, have been reported (30, 31). After tumor removal, the signs and symptoms of precocious puberty resolved, and the previously elevated serum LH and testosterone levels returned to normal in both cases, suggesting that LH secretion by the adrenocortical tumor was the cause of precocious puberty. Although large quantities of LH were found in tumor extracts and there was positive immunohistochemistry for LH in the tumor cells, electron microscopy and in situ hybridization studies were not performed.
The pathogenesis of pancreatic endocrine tumors is unknown. A number of somatic mutations of different oncogenes or tumor suppressor genes, such as K-ras, p53, c-erbB2, Rb (retinoblastoma gene), DPC4 (Smad4), CDKN2A/16p, and multiple endocrine neoplasia type 1 gene, that have been identified in other malignant neoplasms are claimed to be either rare or absent in pancreatic endocrine tumors (32, 33, 34). Various growth factors, among them steroidogenic factor-1 (SF-1), have been implicated in gonadotroph cell proliferation and differentiation. SF-1 is expressed and located in the nuclei of gonadotroph cells of the normal pituitaries (35). Targeted disruption of SF-1 gene in mice results in loss of GnRH receptor expression and selective impairment of gonadotroph cell development (36). Studies of human pituitary tumors showed that SF-1 expression is characteristic of FSH-/LH-producing adenomas as well as of null cell adenomas and oncocytomas that are known to produce ß-FSH/ß-LH subunits (37).
Stromal hyperthecosis (SHT) is characterized by nonneoplastic proliferation of luteinized ovarian stromal cells frequently accompanied by some degree of stromal hyperplasia (SHP). Luteinized granulosa-thecal cell tumors are rare steroid-producing tumors of the ovaries usually occurring in postmenopausal women (80%). They are small, less than 3 cm in size, and with rare exceptions, unilateral. They originate in stromal luteinized cells as in SHT and are accompanied by SHP in approximately 92% of cases, suggesting that SHP may be the first disorder of the disease, followed by SHT and subsequently by the development of luteinized granulosa-thecal cell tumors. Our case supports this sequence of events. Although the cause of SHT and luteinized granulosa-theca cell tumor formation is obscure, it is general knowledge that LH and/or hCG are the main factors in the development of the disease. Ovarian interstitial cells have specific high-affinity receptors for LH; during protracted stimulation they undergo dramatic morphological changes, as shown by in vitro studies (6). hCG-secreting trophoblastic tumors as well as pregnancy induce extensive luteinization of the ovarian stroma and may result in hyperthecosis and, rarely, formation of ovarian granulosa-thecal cell tumor, also known as pregnancy thecoma or luteoma (7, 8, 38). Activating mutations of the gene encoding the LH receptor (39) or the
-subunit of Gs (40) have been identified in a number of Leydig cell tumors of both men and women. However, the most convincing evidence for the casual role of LH in SHT and ovarian tumor formation was provided by recent studies using transgenic mice. Targeted overexpression of LH in transgenic mice leads to infertility, PCOS, ovarian hyperemia, and ovarian granulosa and stromal tumors (27, 41). In these mice, the first histological finding before tumor development was marked ovarian SHP. Gonadotropin hypersecretion was suggested as a mechanism for tumor formation in ovaries transplanted to the spleen in ovariectomized rats (42), in women receiving long-standing human menopausal gonadotropin treatment for infertility (43), and in ovaries of inhibin-deficient transgenic mice (44).
However, LH excess alone cannot explain the development of the disease in either pre- or postmenopausal women, because hyperthecosis is a very rare condition in both, and in premenopausal women, immunoreactive serum LH concentrations are within the normal range. These findings suggest that the causes of stromal cell tumor formation are likely to be heterogeneous, and other factors may also be involved in the development of the disease. One of them may be insulin resistance/hyperinsulinemia, a very common finding in women with SHT, correlated with the ratio of bioactive/immunoreactive LH (45). It is conceivable that alterations in other stimulating factors, such as SF-1, steroidogenic acute regulatory protein, Mullerian duct inhibitory factor, GATA-binding proteins, and FOG-2 (friend of GATA), may also play a role in neoplastic transformation. In our case, both ovarian tumors were strongly immunopositive for
- and ß-inhibin, which are involved in steroidogenesis and tumor formation (46, 47).
In summary, we have reported a rare case of a pancreatic endocrine tumor secreting bioactive LH accompanied by luteinized granulosa cell tumors of both ovaries. We want to call attention to this clinical entity in women presenting with symptoms/signs of hyperandrogenism and luteinized granulosa-thecal cell ovarian tumors associated with highly elevated LH levels.
| Footnotes |
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Abbreviations:
4A,
4-Androstenedione; CT, computer tomography; DHEA-S, dehydroepiandrosterone sulfate; E2, estradiol; FT, free testosterone; hCG, human chorionic gonadotropin; MRI, magnetic resonance imaging; PCOS, polycystic ovary syndrome; PRL, prolactin; SF-1, steroidogenic factor-1; SHP, stromal hyperplasia; SHT, stromal hyperthecosis;
-SU,
-subunit of glycoprotein hormone.
Received November 20, 2003.
Accepted December 6, 2004.
| References |
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- and ß-subunit gene expression in normal and neoplastic tissues characterized using specific messenger ribonucleic acid hybridization probes. J Clin Endocrinol Metab 64:319327
-subunit promoter/simian virus 40 T-antigen fusion gene. Endocrinology 138:35213531
-subunit promoter/simian virus 40 T-antigen fusion gene. Mol Endocrinol 12:801809
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