Prolactin-producing pituitary adenoma with incomplete neuronal transformation: an intermediate adenoma–neuronal tumor

We present a unique case of a prolactin (PRL)-producing pituitary adenoma showing incomplete neuronal differentiation without ganglion cells. A 27-year-old man presented with nausea, headaches, and instability over the last 2 months. Clinical examination revealed obesity with no other endocrinological signs. His serum PRL levels were slightly elevated (38 ng/ml), whereas concentrations of the other adenohypophysial hormones were within normal range. Histology revealed an unusual pituitary adenoma containing many hypocellular areas with fibrillar appearance. The sizable tumor cells were polyhedral or elongated harboring an ovoid, vesicular nucleus with prominent nucleolus, lacking, however, the typical features of ganglion cells. By immunohistochemistry, many adenoma cells were positive for PRL. Immunostain for neurofilament protein revealed variable amounts of fibrils dispersed throughout the stroma, mostly in the hypocellular areas. In addition, neurofilament protein and chromogranin were strongly reactive in approximately 15% of the tumor cell population, whereas reactivity for synaptophysin was uniform throughout the tumor. These findings led to the conclusion that part of the tumor-cell population expressed a hybrid immunoprofile of adenoma–neuronal cell. Our case is the first PRL-producing pituitary adenoma showing incomplete neuronal differentiation lacking mature ganglion cells.     

Ossifying pituitary adenoma co-existing with astrocytoma and pituitary adenoma associated with gangliocytoma: two unusual conditions

Bone formation in pituitary adenoma is an extremely rare finding. Only five previous cases have been published. This is the sixth case report of an ossifying pituitary adenoma and the first case report of a pituitary adenoma with bone formation coexisting with WHO grade II astrocytoma. MRI imaging revealed an unusual eggshell cap-like calcified structure surrounding the tumor. Histologically, the adenoma contained irregularly anastomosing trabeculae with well-formed lacunae and osteoblasts along the margins. Our second case concerns a 25-year-old male patient who presented with complains of off and on headache for 12 months. MRI (head) revealed a 4x3cm well defined rounded lesion in the sella and suprasellar extension that was isointense in T1, hyperintense on T2 with cystic areas and homogenous contrast enhancement. On morphological examination, a cellular tumor admixed with foci of large ganglion cells embedded in a neuropil stroma was noted. On immunohistochemistry, tumor cells were focally positive for pancytokeratin, growth hormone and synaptophysin; and ganglion cells were positive for neurofilament and synaptophysin. No GFAP positive cells were seen. The Ki67 index was < 1%. Based on these findings, a diagnosis of gangliocytoma associated with pituitary adenoma was considered.     

Pituitary prolactin producing adenoma with ossification: A rare histological variant and review of literature

Pituitary adenoma with ossification is a rare histological variant. Previously there have been four cases reported in the literature. Here a case of pituitary prolactin‐producing adenoma with bone formation in a 21‐year‐old woman is described. The patient had irregular menstruation for three years. MRI revealed an unusual 1.5 cm³ ovoid nodule with partial shell‐like structure showing heterogeneous signals. The pre‐operative prolactin serum level was 258.78 ng/mL. The patient was operated through the trans‐sphenoidal pathway under general anesthesia. Histologically, the tumor was parenchymal and mostly replaced by the well‐differentiated lamellar bony tissue. Sheets of tumor cells interweaved with the mature lamellar bone trabeculae showing no cellular atypia. The cytoplasm of the adenoma cells was slightly eosinophilic and the myelo‐adipose metaplastic foci were also found within the parenchyma. Immunohistochemical staining of tumor cells showed positive expressions of prolactin, synaptophysin and chromogranin A in the cytoplasm of the tumor cells. Meanwhile, negative expressions of S‐100, epithelial membrane antigen, GFAP and other pituitary hormones were also demonstrated. As a rare histological variant of pituitary adenoma, the current case of pituitary prolactin producing adenoma with ossification is reported. It is speculated that the ossification may be derived from the osteo‐metaplasia of mesenchymal fibroblasts resulting from the effects of both secondary ischemia by the outgrowth of the tumor and/or the autocrine effect of prolactin in this case. The bony shell structure may limit the growth of pituitary adenoma.     

过氧化物酶体增殖物激活受体γ在垂体腺瘤中的表达

目的 通过检测过氧化物酶体增殖物激活受体γ(PPARγ)在人垂体腺瘤组织中的表达,探讨其在垂体腺瘤中的相关机制.方法 通过免疫组化法确定经手术切除的83例垂体腺瘤组织细胞来源;采用RT-PCR、适时定量PCR检测研究83例垂体腺瘤组织及6例正常垂体组织PPARγ的mRNA表达量,采用Western blot法检测组织PPARγ蛋白质表达水平,分析不同类型垂体腺瘤组织之间核酸及蛋白水平表达量的差异.结果 GH腺瘤17例、PRL腺瘤15例、ACTH腺瘤18例、多激素腺瘤(MCPAs)17例、无功能腺瘤(NFAs)16例及正常对照组6例;mRNA水平检测显示所有垂体腺瘤组织的表达量均高于正常对照组,其中GH腺瘤的表达量最高,与其他组比较P＜0.05;蛋白水平检测显示GH腺瘤、PRL腺瘤、ACTH腺瘤及MCPAs的表达量均高于正常对照组(P＜0.05),GH腺瘤的表达量最高,NFAs的表达量与正常对照组差异无统计学意义(P＞0.05).结论 PPARγ转录及蛋白表达水平在人GH、PRL、ACTH及MCPAs垂体腺瘤组织中高表达,该基因与垂体腺瘤有一定的相关性,而无功能垂体腺瘤在核酸水平的表达量增高,蛋白水平的表达量不高,可能与激素的分泌水平有关;在GH腺瘤中的表达量最高,且与其他组相比,差异有统计学意义(P＜0.05),说明该类肿瘤与PPARγ的关系最为密切,可能与生长激素能刺激PPARγ的表达有关.     

Ganglion cell containing pituitary adenomas: signs of neuronal differentiation in adenoma cells

Ganglion cell containing pituitary adenomas are rare. They represent tumors originating in the sella turcica which are composed of adenomatous and neuronal components. Recently accumulated information suggests a common origin for their neuronal and pituitary constituents. The objective of this study was to report the clinical and morphologic findings of pituitary gangliocytomas and study their immunoprofile using neuronal markers. Seven cases of pituitary gangliocytomas retrieved from 1,322 sellar lesions were studied. All tumors were removed from patients with mild acromegaly. Histologically they were biphasic composed of pituitary adenoma and clusters of ganglion cells embedded in a variably dense neuropil substrate. All adenomas belonged to the category of sparsely granulated somatotroph adenoma and were positive for growth hormone, whereas in five tumors, a few adenoma cells were also positive for prolactin. Ganglion cells were immunoreactive for NSE, synaptophysin and neurofilament protein (NFP). NFP-reactive fibrils were observed in the neuropil substrate and varied in number among the cases. Interestingly, all tumors contained varying numbers of adenoma cells with NFP-positive, dot-like areas of cytoplasmic reactivity, mostly tiny paranuclear, a finding not previously reported in human pituitary gangliocytomas. The presence of NFP in pituitary adenomas indicates neuronal differentiation in adenoma cells, suggesting a common origin for neuronal and pituitary adenoma cell elements in gangliocytomas.     

Thyrotropin secreting pituitary adenoma accompanying a silent somatotropinoma

Thyroid stimulating hormone (TSH) secreting pituitary adenomas are rare tumors manifested as hyperthyroidism with goiter in the presence of elevated TSH. We present a case with pituitary adenoma secreting both TSH and growth hormone (GH) with the prominent clinical findings of hyperthyroidism but without clinical findings of acromegaly. Pituitary magnetic resonance imaging revealed a macroadenoma. Transsphenoidal surgery was performed twice. The immunohistochemical staining showed that tumor cells were strongly reactive to GH and relatively mildly reactive to TSH. Control pituitary imaging revealed a residual macroadenoma, and long acting octreotide treatment was administered. After two years of the treatment, tumor size remained the same while thyroid function tests and insulin-like growth factor 1 (IGF-I) values returned to normal ranges. In conclusion, we always recommend hormonal examinations for all patients who have pituitary adenoma without signs and symptoms of acromegaly.     

A case of pituitary adenoma with simultaneous secretion of TSH and GH detected by double immunostaining method

A rare case of simultaneous hypersecretion of thyroid stimulating hormone (TSH) and growth hormone (GH) in a pituitary adenoma is reported. A 59-year-old male complaining of general fatigue, dyspnea on exertion and finger tremor was admitted. Examination on admission, he revealed with hyperthyroidism and hypersecretion of TSH and thyroid hormones. Administration of TRH did not further increase serum TSH level, and administration of T3 also had no effect on TSH secretion. CT scan showed a pituitary macroadenoma 13mm in diameter. MRI demonstrated a homogenously hypointense mass with Gd-DTPA enhancement in the left side of the sella turcica. The entire chromophobic adenoma was removed by trans-sphenoidal surgery. Immunostaining of the specimen showed that the cytoplasm of the adenoma cells was positive for both TSH and GH. Double immunostaining using avidin-biotin-peroxidase complex (ABC) method and immunogold silver staining (IGSS) method, showed that the adenoma cells had been secreting both GH and TSH at the same time. After the adenomectomy, the hyperthyroidism disappeared, and all altered indicators of pituitary function returned to normal.     

Intrasellar neuronal hamartoma associated with pituitary adenoma. Case report

46-year-old acromegalic women presenting high level of growth hormone (32 ng/ml) in the serum underwent surgery. The intrasellar tumor, 16 mm in diameter, has been removed. The biopsy material consisted of two types of closely adjacent and intermingled tissues, one of which was growth hormone positive acidophilic adenoma, the second component were haphazardly oriented ganglion cells of various size and shape, also multinuclear, with bundles of unmyelinated fibers. The cytoplasm and processes of ganglion cells were immunopositive for neurofilaments and for synaptophysin on cellular membranes and processes. There were none glial fibrillary acidic protein positive cellular elements. The authors discuss commonly used name of choristoma for this type of tumor and the problem of possible neurosecretory stimulation of pituitary adenoma by neuronal hamartoma.     

Intrasellar hamartoma associated with pituitary adenoma

Summary The histological, ultrastructural and immunocytochemical features are reported of an intrasellar neuronal and lipomatous hamartoma associated with pituitary growth hormone (GH) cell adenoma and acromegaly. Electron microscopy demonstrated a close contact between neurons and adenomatous GH cells. By immunohistochemistry the adenoma cells revealed a positive staining for GH and prolactin. the neurons of hamartoma showed neurosecretory activity which might have induced the development of pituitary GH cell adenoma.     

A case of non‐functioning pituitary adenoma with Cushing's syndrome upon recurrence

A 49‐year‐old woman presented with left visual disturbance. No signs of Cushing's disease were evident. Basal levels of serum cortisol and plasma adrenocorticotropic hormone (ACTH) were 16.8 μg/dL and 66.0 pg/mL, respectively. MRI demonstrated an irregularly shaped large pituitary tumor, and the patient then underwent transsphenoidal surgery. By light microscopy the tumor represented a chromophobic adenoma with a few of the adenoma cells showing immunoreactivity for ACTH. On the basis of clinical and light microscopic examinations, the diagnosis of silent corticotroph adenoma was made. Electron microscopy, however, demonstrated the honeycomb Golgi complex that has been reported as a typical finding of gonadotroph adenomas. MRI taken 7 months after the first operation revealed adenoma regrowth. Transcranial surgery was performed, and histology demonstrated a chromophobic pituitary adenoma with most cells immunopositive for ACTH. She was treated with gamma knife postoperatively. Three months later, MRI revealed remarkable shrinkage of the adenoma, but she developed typical signs and symptoms of Cushing's disease. Thus, the hormone immunostaining and biological activity of pituitary adenomas may change with time.     

Difference of lectin binding sites of secretory granules between normal pituitary and adenoma cells

Summary Electron-immunocytochemical staining with lectin (concanavalin A: Con A) binding sites analysis was applied to study secretory granules of human pituitary adenomas and surrounding normal pituitary tissue using post-embedded serial ultrathin sections. Twelve cases of human pituitary adenoma and three specimens of normal pituitary tissue surrounding adenomas were studied: the cases were operated on between 1982 and 1984. The tumors consisted of four prolactin (PRL)-, six growth hormone (GH)-, and two adrenocorticotropic hormone (ACTH)-producing adenomas.In parallel with the detection of Con A binding sites of secretory granules, their secreting hormones were characterized electron-microscopically with the immunocytochemical horseradish peroxidase (HRP) labeling using the avidin-biotin technique. The two cases of ACTH-producing adenomas showed either weak or negative reactions with Con A on secretory granules, while normal ACTH-producing pituitary cells showed strong reactions with Con A on every secretory granule observed. Large secretory granules of PRL- or GH-producing cells showed negative reactions with Con A both in the pituitary adenoma and normal pituitary, while some small granulated or sparsely granulated adenoma cells also showed strong reactions with Con A.The complexity of human pituitary adenomas is illustrated as well as the difference in biochemical structure of normal pituitary cells and pituitary adenoma cells secreting the same specific hormone.     

Up-regulation of fast-axonally transported proteins in retinal ganglion cells of adult rats with optic–peroneal nerve grafts

Metabolic labeling and quantitative 2D gel fluorography were used to assess changes in the synthesis and transport of five fast-axonally transported and developmentally regulated proteins (GAP-43, SNAP-25, and proteins of 18, 22, and 23/24 kDa) after grafting of a peroneal nerve segment onto a transected optic nerve in adult rats. After optic nerve transection alone, only GAP-43 was up-regulated significantly compared to normal adult controls. The other proteins showed little change or were down-regulated following axotomy. By 4 weeks following optic nerve transection and peroneal nerve grafting, however, GAP-43, proteins 22 and 23/24 kDa showed a sustained up-regulation in synthesis and transport compared to normal controls; SNAP-25 and protein 18 kDa showed levels of expression similar to or slightly greater than normal controls. Increased expression of GAP-43 in retinal ganglion cells was also examined with immunocytochemistry. While a transient up-regulation of GAP-43 in retinal ganglion cells was observed following optic nerve transection, a sustained increase in GAP-43 immunoreactivity was present only in animals with nerve grafts. Backfilling of retinal ganglion cells from the grafts with horseradish peroxidase combined with GAP-43 immunocytochemistry revealed that all retinal ganglion cells with axons growing into the grafts were positive for GAP-43, but not all retinal ganglion cells showing GAP-43 immunoreactivity were extending axons into the grafts. We conclude that the presence of a nerve graft sustains the up-regulation of a number of proteins including GAP-43, and that this up-regulation is correlated with an increased potential for nerve growth, but other as yet unknown factors or conditions appear to play a role in determining if this growth potential will be realized.     

Growth hormone secreting adenoma with unusual extension: coexisting pituitary cyst and its clinical significance.

A 58 year old man showed acromegalic features. The serum growth hormone (GH) level was 7.3 ng/ml and SMC (somatomedin-C) 637 U/ml. Triple stimulation test showed abnormal response compatible with a GH secreting tumour. The conventional enhanced MRI revealed a less enhanced hemisphere-shaped lesion at the right corner of the sella turcica. In addition, dynamic MRI demonstrated an elongated lesion extending to the left beyond the midline. The patient underwent transsphenoidal surgery. Besides the soft and suckable tumour at the right corner, we entered into a small cavity loosely filled with the tumour, which was subsequently also removed. The operative finding corresponded to the lesion shown in dynamic MRI. Postoperative GH and SMC levels became 2.3 ng/ml and 326 U/ml respectively. Incidental pituitary cystic lesions in autopsied cases have been reported to be 6-33%. This case had a GH secreting adenoma with coexisting pituitary cyst. The coexisting pituitary cyst supposedly influenced the unusual shape and extension of the pituitary adenoma. Coexistence of such lesion should be kept in mind for microadenoma on neuroradiological evaluation and on intraoperative inspection surrounding the tumour.     

Localization and Axotomy-induced Regulation of the Peptide Secretoneurin in the Rat Superior Cervical Ganglion

This study demonstrates the localization and regulation of a novel neuropeptide of 33 amino acids, secretoneurin (SN), in the rat superior cervical ganglion. Gel filtration chromatography of ganglion proteins followed by a specific radioimmunoassay revealed that SN is the predominant cleavage product of secretogranin II, a member of the chromogranin/secretogranin protein family, in adult ganglia. SN was detected within the majority of nerve endings surrounding postganglionic neurons that were identified by the presence of synaptophysin and, in part, colocalized leu-encephalin. Applying immuno-electronmicroscopy, SN was localized to large dense core vesicles of neuronal and small intensely fluorescent (SIF) cells. In situ hybridization revealed the presence of secretogranin II mRNA in postganglionic neurons and, to a lesser extent, in SIF cells. One week after transection of the postganglionic branches SN levels were not significantly altered; however, a decrease of secretogranin II mRNA was observed in postganglionic neurons but not in SIF cells. After decentralization of the ganglion, SN-immunoreactive nerve terminals disappeared and intraganglionic SN levels were reduced by 70%, indicating the preganglionic origin of SN-positive nerve fibres and varicosities. Secretogranin II mRNA was slightly reduced under this condition. Combined axotomy and decentralization further diminished intraganglionic secretogranin II mRNA, although peptide levels increased significantly above control values under these conditions. Double-labelling immunofluorescence with antibodies against the somatodendritic marker microtubule-associated protein 2 (MAP2) revealed that the increase in SN immunoreactivity was due to an accumulation of SN in axonal processes of postganglionic neurons. SN immunoreactivity was also detected in dissociated neonatal superior cervical ganglion cultures and increased significantly upon treatment with nerve growth factor, the survival and differentiation factor of sympathetic neurons during perinatal development. Co-culture with non-neuronal cells or addition of leukaemia inhibitory factor, a cytokine known to stimulate synthesis of various peptides after nerve transection, did not influence SN immunoreactivity. Therefore, since no fixed relationship between SN and any of the known neuropeptides or neurotransmitters expressed in sympathetic neurons was observed, the expression of this novel peptide appears to be independently regulated.     

T cell lymphoblastic lymphoma/leukemia within an adrenocorticotropic hormone and thyroid stimulating hormone positive pituitary adenoma: A cytohistological correlation emphasizing importance of intra‐operative squash smear

We present a rare case of primary pituitary T cell lymphoma/leukemia (T‐LBL) in association with adrenocorticotropic hormone (ACTH) and thyroid stimulating hormone (TSH) expressing pituitary adenoma in a 55‐year‐old woman highlighting the importance of intra‐operative squash smears examination. The patient presented with complaints of headache, diminution of vision and recent onset altered sensorium. MRI revealed a mass lesion in the sellar‐suprasellar region with non‐visualization of pituitary gland separately, extending to involve adjacent structures diagnosed as invasive pituitary macroadenoma. Intra‐operative tissue was sent for squash smear examination. The cytology showed a tumor comprising of sheets of immature lymphoid cells intermixed with clusters of pituitary acinar cells with many mitoses and tingible body macrophages. A diagnosis of presence of immature lymphoid cells within the pituitary was offered and differentials of infiltration by lymphoma cells from systemic disease versus primary central nervous lymphoma‐like lymphoma arising in the pituitary adenoma were considered. Later paraffin section examination and immunohistochemistry corroborated with the squash findings and a final diagnosis of primary pituitary T cell lymphoma/leukemia in association with ACTH and TSH expressing pituitary adenoma was made. To date, only six cases of primary pituitary T cell lymphomas, including three T‐LBL cases, have been reported. This is the seventh case and first one additionally describing cytohistological correlation and importance of intra‐operative cytology.     

Growth hormone localization in the neural retina and retinal pigmented epithelium of embryonic chicks

It is well-established that growth hormone (GH) is present in the brain, spinal cord, and peripheral nerves of embryonic chicks, prior to the differentiation of pituitary somatotrophs, but its presence and distribution in retinal tissues is controversial. The possible presence of GH and GH mRNA in retinal tissues of early embryos has therefore been further evaluated. A 466-bp fragment of the pituitary GH cDNA, derived from a portion of exon 3 and spanning exons 4 and 5, was amplified by RT-PCR from reverse-transcribed mRNA from the pituitary glands of juvenile chicks and from the whole eye, neural retina, and retinal pigmented epithelium (RPE) of embryonic-day (ED) 9 chick embryos. In ED 9 embryos, GH immunoreactivity was demonstrated in the choroid and neural retina, in which it was particularly abundant in a layer of cells with the location and morphological appearance of retinal ganglion cells. GH immunoreactivity was also present in tissue sections of the RPE that were bleached to remove the melanin pigment. The intense GH staining in the RPE of ED 9 embryos was also revealed using a fluorescein-labeled GH antibody and confocal microscopy. At the ultrastructural level, GH detected by immunogold electron microscopy was present in the cytoplasm of RPE and neural retinal cells of ED 9 embryos. Although not associated with secretory granules, GH in the RPE was particularly associated with the membranes of the melanin granules. These results demonstrate that the neural retina and RPE are extrapituitary sites of GH production in early chick embryos, prior to the differentiation of the pituitary gland.     

内窥镜辅助下经单鼻腔蝶窦入路切除垂体腺瘤

目的　探讨局部麻醉下利用内窥镜辅助 ,经单鼻腔蝶窦入路切除垂体腺瘤的可行性、优缺点 ,适应证及注意事项。方法　采用MRI明确诊断 ,使用局部麻醉内窥镜电视监测下经单鼻腔蝶窦入路进行垂体腺瘤切除。结果　 30例病人中 2 5例肿瘤全切除 ,5例次全切除。术后 2～ 4小时病人即可下床活动 ,进食。术后平均 4天出院 ,无死亡、无感染。术后脑脊液鼻漏 1例 ,再次经鼻蝶入路修补后痊愈。随访 6～ 4 8个月 ,视力恢复到 1.0以上10例 ,内分泌功能正常 15例 ,月经恢复正常 10例。结论　内窥镜辅助下经单鼻腔切除垂体瘤使用局部麻醉是安全可行的 ,手术对病人的损伤和影响可以达到最低程度     

Pituitary adenoma calcification

Three hundred and eighteen cases of functioning and non-functioning pituitary adenoma were examined by histological, immunocytochemical and electronmicroscopic technique. Fourty-four of them (13.8%) showed evidence of calcospherites in the tumor tissues. A high incidence of calcospherite is found in functioning adenoma, but not in non-functioning adenoma. Calcification was seen most frequently in cases of prolactinoma (23), GH secreting (7), or GH + PRL tumor (2) and less in adrenocorticotropic hormone secreting adenoma (2) and follicle stimulating hormone secreting adenoma (1). Prolactin and growth hormone might be involved in the control of calcium metabolism. This is because, following adenomectomy in patients with prolactinoma or GH-secreting adenoma with hypercalcemia, there is normalization of serum PRL and GH with reduction in serum calcium. Calcospherite is produced in all of metastatic calcification, arterial calcification, dystrophic calcification and calcinosis. In cases of non-functioning adenoma however, the mechanism is believed to by dystrophic calcification.     

Immunocytochemical Demonstration of CB1 Cannabinoid Receptors in the Anterior Lobe of the Pituitary Gland

Both exogenous and endogenous cannabinoids can influence hormone secretion from the anterior pituitary gland. A large body of information proves that the primary target of these effects is the neuroendocrine hypothalamus. However, recent studies using cannabinoid (CB) receptor autoradiography, messenger RNA in-situ hybridization and in-vitro analysis, indicate direct effects of cannabinoids at the level of the anterior pituitary gland itself. In the present paper, the immunocytochemical distribution of CB in the adult rat anterior pituitary was studied using specific polyclonal antibodies against CB1 (central) and CB2 (peripheral) receptors. Due to its resolution, this method allowed identification of individual anterior pituitary cells possessing cannabinoid receptors. The specific hormone immunoreactive cells with receptor-like immunoreactivity were compared on adjacent sections. CB1-like immunoreactivity (CB1ir) was found in the lactotroph cells as well as in luteinizing hormone (LH) secreting gonadotrophs. The CB1ir positive material present in the cytoplasm of these cells was less homogeneous than the hormone immunoreactive material, and it was also seen at the periphery of the cells, presumably on the cell membrane. No CB1ir was found in growth hormone (GH) secreting cells and it was hardly seen in the corticotrophs. No CB1ir was detected in the posterior pituitary. CB2ir was not observed in any part of the pituitary gland. The results support the view that the site of action of cannabinoids on neuroendocrine regulatory mechanisms may be both at pituitary and hypothalamic levels. We suggest that at least the direct effect of cannabinoids on the regulation of LH and prolactin secretion is mediated via CB1 cannabinoid receptors in the anterior pituitary.