Progression on metastatic neuroendocrine carcinoma from a recurrent prolactinoma: a case report

Corticotrophic pituitary carcinoma with cervical metastases: case series and literature review

PURPOSE

Pituitary tumors are the second most common intracranial tumors, however, pituitary carcinoma is a rare clinical entity which represents only 0.1-0.2% of all pituitary tumors. Diagnosis of pituitary carcinoma requires the presence of metastasis. Early identification of pituitary carcinoma is difficult, and only recently have guidelines been published for the treatment of aggressive pituitary tumors. We present two cases from our institution, with a review of other cases available in literature in order to better characterize this rare disease.

METHODS

A retrospective review of two patients with pituitary carcinoma treated at a tertiary medical center was performed. The MEDLINE database was searched for all cases of pituitary carcinoma. Information for age at diagnosis, sex, pituitary tumor type, latency period from pituitary tumor to presentation of carcinoma, sites of metastasis, number of surgical therapies, radiation and chemotherapy, and survival after diagnosis were collected.

RESULTS

A total of 69 studies were available for review for a total of 72 unique cases. The average age at diagnosis was 46.3 years. The most common tumors were ACTH-secreting (34.7%), Prolactin-secreting (23.6%), and Null Cell (15.3%). The average latency period from pituitary tumor diagnosis to metastasis was 9 years. All patients underwent surgical therapy during their treatment, with an average of 2.76 procedures. The mortality rate was 54.8% with average time to death after diagnosis of approximately 10 months.

CONCLUSIONS

Pituitary carcinoma is a rare disease with high mortality rate and is a diagnostic and treatment challenge. Further study is required but is difficult due to its low incidence.

MicroRNA involvement in a metastatic non-functioning pituitary carcinoma

PURPOSE

Pituitary carcinomas are extremely rare neoplasms, and molecular events leading to malignant pituitary transformation are largely unknown. Enhanced understanding of molecular mechanisms driving malignant pituitary progression would be beneficial for pituitary carcinoma diagnosis and treatment.

METHODS

Differential microRNA expression in paired primary and metastatic pituitary carcinoma specimens were detected using high-throughput human microRNA microarrays and TaqMan microRNA arrays. Three of significantly deregulated miRNAs were further confirmed using quantitative real-time PCR in the metastatic carcinoma, six atypical pituitary adenomas and eight typical pituitary adenomas. Target genes of microRNAs were bioinformatically predicated and verified in vitro by Western blotting and real-time PCR and in vivo by immunohistochemistry respectively.

RESULTS

We present a case of a 50-year-old woman harboring non-functioning pituitary carcinoma with multiple intracranial metastases, and identified up-regulation of miR-20a, miR-106b and miR-17-5p in the metastatic carcinoma as compared to the primary neoplasm. Furthermore, miR-20a and miR-17-5p were increased in the metastatic carcinoma and six atypical pituitary adenomas as compared to eight typical pituitary adenomas as measured by quantitative real-time PCR. Both PTEN and TIMP2 were bioinformatically predicated and confirmed in vitro as target genes of these three microRNAs. As semi-quantified by immunohistochemistry, PTEN was absent and TIMP2 was decreased in the metastatic pituitary carcinoma as compared to pituitary adenomas.

CONCLUSIONS

Our results suggest microRNA involvement in malignant pituitary progression, whereby increased miR-20a, miR-106b and miR-17-5p promote metastasis by attenuating PTEN and TIMP2 in pituitary carcinoma.

Transsphenoidal surgery for malignant pituitary lesions: an analysis of inpatient complications

BACKGROUND

Fewer than 4% of pituitary tumors are malignant lesions. These tumors predominantly represent metastatic disease from elsewhere. This study evaluates inpatient complications, demographics, and hospitalization characteristics of patients who underwent transsphenoidal surgery (TSS) for malignant pituitary lesions.

METHODS

The Nationwide Inpatient Sample was evaluated for TSS patients from 1998 to 2010. Demographics, hospitalization characteristics, and complications were evaluated among patients with malignant lesions and compared to those with benign tumors.

RESULTS

There were 17,425 inpatient records, 1.0% of which involved malignant pituitary tumors. There was no difference in age between these cohorts (p = 0.378). Patients with malignant tumors had greater length of stay (6.7 days vs 4.5 days, p = 0.003) and higher trending charges ($55,371 vs $40,550 p = 0.091). The most common postoperative complications among patients with malignant lesions included diabetes insipidus (DI) (17.9%), fluid/electrolyte abnormalities (14.0%), neurological complications (5.6%), cerebrospinal fluid (CSF) rhinorrhea (2.2%), and iatrogenic pituitary disorders (2.2%). Patients with malignant lesions had a significantly greater rates of postoperative DI and fluid/electrolyte abnormalities (odds ratio = 2.0 and 1.7, respectively), whereas no statistical difference was noted in the rates of CSF rhinorrhea (p = 0.372).

CONCLUSION

In this analysis of inpatient hospitalizations for TSS patients, malignant pituitary disease was associated with a greater rate of postoperative DI and fluid/electrolyte abnormalities, but no differences in the rates of postoperative CSF rhinorrhea and other complications were found. Patients with malignant pituitary lesions undergoing TSS had significantly longer hospitalizations and higher trending charges than those with benign lesions. This analysis is, however, subject to the limitations of the database.

Orbital metastasis of pituitary growth hormone secreting carcinoma causing lateral gaze palsy

Background:

Although pituitary adenoma is one of the most common intracranial tumors, it rarely progresses secondarily into a metastatic carcinoma. Commonalities in reported cases include subtotal resection at presentation, treatment with radiation therapy, and delayed metastatic progression. Pathologic descriptions of these lesions are varying and inconsistent.

Case Description:

A 52-year-old male was diagnosed with acromegaly and pituitary tumor in 1996. He underwent four subtotal resections and five courses of stereotactic radiosurgery over 14 years. He developed left eye lateral gaze palsy, and was found to have a distant orbital metastasis with involvement of the left lateral rectus and lateral orbital wall. He underwent left orbital craniotomy via eyebrow incision for resection of this lesion. Pathologic evaluation showed a markedly elevated Ki67 level of 30%.

Conclusion:

While overall incidence of metastatic progression of pituitary adenoma after radiotherapy appears to be low, it appears to be a possible complication, and could be more likely in patients receiving multiple doses of radiotherapy. Our review of reported cases showed that 45/46 (97.8%) of patients developing carcinoma had prior radiation exposure. These patients may also have more aggressive pathologic characteristics of their lesions.

Atypical pituitary adenoma with malignant features

Pituitary carcinoma is characterized by the presence of systemic or central nervous system metastases rather than malignant histological features, making it an anomaly amongst carcinomas. In contrast, aggressive or atypical pituitary adenomas often have a relatively bland histological appearance despite their malignant growth patterns. We now report a case of a 67-years-old male with a giant pituitary tumor with overt pathologic and phenotypic features of malignancy, but the absence of metastases, that evolved from a benign non-functioning gonadotroph macroadenoma treated 10 years earlier. This case represents the first report of a pituitary adenoma with overt malignant histology that does not meet criteria for classification as pituitary carcinoma, helping to complete the pathological spectrum of disease observed with pituitary tumors.

Somatostatin-producing atypical null cell adenoma manifesting as severe hypopituitarism and rapid deterioration--case report

Atypical adenoma has an aggressive biological character, invades the surrounding structures, and grows rapidly. Morphological malignant findings such as increasing cellularity and nuclear atypism are not involved in this entity, but some cases with overt malignant features such as significant nuclear atypism and/or necrosis are known. Null cell adenoma generally grows slowly, but hormone secretion is little understood. Atypical null cell adenoma is rare, and hormone production is unknown. A 55-year-old woman presented with severe hypopituitarism and diabetes insipidus and bilateral upper temporal quadrantanopsia. Head magnetic resonance imaging revealed a large sellar tumor compressing the optic chiasm. Transsphenoidal surgery was performed, but the tumor was partially removed because of invasion into the neuronal structures. Histological examination showed atypical null cell adenoma with significant nuclear atypism and extensive necrosis. Immunohistochemistry showed positive reaction to somatostatin. Adjuvant treatment was planned, but the tumor regrew within 3 months. Conventional irradiation resulted in slight decrease in tumor size, but she required assistance for every type of daily activity. Atypical null cell adenoma has an aggressive biological character, and immediate adjuvant treatment is essential. Somatostatin secretion was proven in this tumor type.

Advances in the treatment of prolactinomas

Prolactinomas account for approximately 40% of all pituitary adenomas and are an important cause of hypogonadism and infertility. The ultimate goal of therapy for prolactinomas is restoration or achievement of eugonadism through the normalization of hyperprolactinemia and control of tumor mass. Medical therapy with dopamine agonists is highly effective in the majority of cases and represents the mainstay of therapy. Recent data indicating successful withdrawal of these agents in a subset of patients challenge the previously held concept that medical therapy is a lifelong requirement. Complicated situations, such as those encountered in resistance to dopamine agonists, pregnancy, and giant or malignant prolactinomas, may require multimodal therapy involving surgery, radiotherapy, or both. Progress in elucidating the mechanisms underlying the pathogenesis of prolactinomas may enable future development of novel molecular therapies for treatment-resistant cases. This review provides a critical analysis of the efficacy and safety of the various modes of therapy available for the treatment of patients with prolactinomas with an emphasis on challenging situations, a discussion of the data regarding withdrawal of medical therapy, and a foreshadowing of novel approaches to therapy that may become available in the future.

Pancreatic neuroendocrine tumor with ectopic adrenocorticotropin production upon second recurrence

We present a 54-yr-old woman with ectopic corticotropin syndrome caused by a neuroendocrine tumor of the pancreas. At initial presentation, the patient suffered from diarrhea, heartburn, and nonspecific abdominal pain. There was no evidence of Cushing's syndrome. A neuroendocrine tumor in the head of the pancreas with metastases into peripancreatic lymph nodes was diagnosed and completely resected. Fourteen months later, abdominal computed tomography and scintigraphy with (111)In-labeled octreotide suggested relapse of the tumor. The patient again had no evidence of Cushing's syndrome. A second in toto tumor resection was performed. Another 8 months later, the patient developed forgetfulness, depressive episodes, muscle weakness, new-onset hypertension, hypokalemia, plethora, diabetes mellitus, polyuria, and weight loss. Endocrine testing suggested a source of ectopic ACTH production. An octreotide scan showed an intense uptake ventromedial of the left kidney, an area that showed a mass lateral of the superior mesenteric artery on abdominal magnetic resonance imaging. A complete pancreatectomy with splenectomy and left-sided adrenalectomy were performed. At this second relapse, this neuroendocrine tumor clinically had changed its hormonal profile. Immunohistochemically, in contrast to primary tumor and first relapse, we found strong immunostaining for ACTH in tumor cells of the second relapse and a MIB-1 index greater than 20%. To our knowledge, this is the first report describing a pancreatic neuroendocrine tumor that started to secrete ACTH de novo at the time of the second relapse after two former complete tumor resections. This case underscores the pluripotency of neuroendocrine tumor cells and the importance of keeping in mind a possible shift in hormone production during tumor evolution and progression.

Pituitary carcinoma: a review of the literature

Pituitary carcinomas, defined as distant metastases of a pituitary neoplasm, are rare; fewer than 140 reports exist in the English literature. The initial presenting pituitary tumor is usually a secreting, invasive macroadenoma, with adrenocorticotropic hormone (ACTH)--and prolactin (PRL)--secreting tumors being the most common. The latency period between the diagnosis of a pituitary tumor and the diagnosis of a pituitary carcinoma is 9.5 years for ACTH-producing lesions and 4.7 years for PRL-secreting tumors. Survival after documentation of metastatic disease is poor; 66% of patients die within 1 year. Treatment options include additional surgery, radiotherapy, and chemotherapy, all of which are associated with poor results. Future studies will focus on identifying those invasive pituitary tumors most likely to metastasize and treating them aggressively before they progress to pituitary carcinomas.