ACTH-producing pituitary cancer: experience at the King Faisal Specialist Hospital & Research Centre

Challenges and controversies in the treatment of prolactinomas

Recent studies have reported a higher prevalence of pituitary tumors than previously thought. Among these tumors, prolactinomas occur in up to 66% of cases. Since the mid-1980s, the widespread use of dopamine agonists has facilitated the management of the majority of prolactinomas, allowing biological and tumoral control in most cases. The less frequent cases of resistant prolactinomas remain challenging despite a multimodal therapy approach. The understanding of genetic alterations in familial and aggressive pituitary tumors provides new perspectives in the management of some prolactinomas. Genetic screening should be considered, particularly in familial cases but also in young patients with macroprolactinomas, as some mutations can predict potential aggressiveness.

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.

Altered FDG uptake patterns in pediatric lymphoblastic lymphoma patients receiving induction chemotherapy that includes very high dose corticosteroids

BACKGROUND

Altered FDG uptake patterns were noted in certain lymphoblastic lymphoma patients during therapy.

OBJECTIVE

To describe these altered FDG uptake patterns and their relationship to chemotherapy.

MATERIALS AND METHODS

Thirty-five FDG PET or PET/CT scans obtained in 11 children with lymphoblastic lymphoma were retrospectively reviewed. FDG uptake patterns were recorded. SUV measurements were performed in liver and facial soft tissues. Results were correlated with induction chemotherapy regimens.

RESULTS

Six of the children had transiently altered FDG uptake with increased uptake in the superficial soft tissues, most notably involving the face. Altered uptake was noted approximately 1 month after initiation of chemotherapy and subsequently resolved. Hepatic uptake was transiently reduced on the 1-month scan in all six children with increased facial uptake. No significant FDG uptake in lymphoma was seen on five of six scans with altered uptake; however, two of these five affected children had FDG uptake in lymphoma on the next follow-up examination. Blood glucose levels in the affected children were in the normal range. All six children with altered FDG uptake received the same induction chemotherapy regimen, which included very high doses of corticosteroids.

CONCLUSIONS

Children with lymphoblastic lymphoma on induction chemotherapy protocols including very high doses of corticosteroids transiently demonstrated altered FDG uptake patterns, including increased superficial facial uptake and reduced hepatic uptake. The facial uptake is probably the FDG PET equivalent of Cushingoid facies. Caution in interpreting scans with this altered FDG uptake pattern is suggested, as uptake at sites of lymphomatous involvement may potentially be affected.

Clinical review: Pituitary carcinoma: difficult diagnosis and treatment

CONTEXT

Although pituitary tumors are common, pituitary carcinoma is very rare and is only diagnosed when pituitary tumor noncontiguous with the sellar region is demonstrated. Diagnosis is difficult, resulting in delays that may adversely effect outcome that is traditionally poor. Barriers to earlier diagnosis and management strategies for pituitary carcinoma are discussed.

EVIDENCE ACQUISITION

PubMed was employed to identify relevant studies, a review of the literature was conducted, and data were summarized and integrated from the author's perspective.

EVIDENCE SYNTHESIS

The available data highlight the difficulties in diagnosis and management and practical challenges in conducting clinical trials in this rare condition. They suggest that earlier diagnosis with aggressive multimodal therapy may be advantageous in some cases.

CONCLUSIONS

Although pituitary carcinoma remains difficult to diagnose and treat, recent developments have led to improved outcomes in selected cases. With broader use of molecular markers, efforts to modify current histopathological criteria for pituitary carcinoma diagnosis may now be possible. This would assist earlier diagnosis and, in combination with targeted therapies, potentially improve long-term survival.

Adrenocorticotropic hormone-producing pituitary carcinoma with intracranial metastases

BACKGROUND

Pituitary carcinomas are rare and challenging clinical entities. Because of the paucity of cases, there is limited information in the literature on how best to diagnose and treat pituitary carcinomas.

METHODS

We review the literature and describe a woman who presented with an adrenocorticotropic hormone (ACTH)-secreting pituitary macroadenoma that later evolved into a carcinoma with intracranial metastases.

RESULTS

A 39-year-old woman presented at age 27 with classic findings of Cushing's syndrome and a pituitary macroadenoma. Her initial treatment was transsphenoidal surgery, during which we confirmed an ACTH-secreting pituitary neoplasm. For 5 years, she was asymptomatic before her first recurrence. During the next 6 years, she underwent four transsphenoidal surgeries and two craniotomies. After each surgery, there was some reduction in the size of the macroadenoma but the residual tumor mass would rapidly enlarge. Immunochemical staining was positive for ACTH, and a stain for Ki-67 antigen showed a high mitotic index. Eleven years after her initial presentation, magnetic resonance imaging revealed bilateral hippocampal and tempero-occipital masses. The patient's health continued to deteriorate, largely from complications of severe hypercortisolemia, and she died from sepsis. At postmortem, the hippocampus and tempero-occipital lobe masses proved to be a pituitary tumor with positive ACTH staining.

CONCLUSIONS

Pituitary carcinomas are rare, may present many years after diagnosis of a primary pituitary adenoma, and should be suspected in patients with persistent or recurrent disease. Reliable histopathologic ways to distinguish between carcinoma and adenoma are difficult because the features of hypercellularity, nuclear pleomorphism, and mitotic figures are not always helpful.

A case of corticotroph carcinoma that caused multiple cranial nerve palsies, destructive petrosal bone invasion, and liver metastasis

A 52-year-old woman experienced sudden onset of double vision due to a right abducens nerve palsy and was diagnosed as having a pituitary macroadenoma that invaded into the right cavernous sinus. Otherwise, she was asymptomatic despite marked elevation of ACTH (293 pg/ml) and cortisol (24.6 μg/dl) levels. The patient underwent transsphenoidal surgery followed by γ-knife radiosurgery (GKR), which healed the diplopia and ameliorated the hypercortisolemia. The excised tumor was diffusely stained for ACTH with a high (15%) Ki-67 labeling index. Early tumor recurrence occurred twice thereafter, producing right lower cranial nerve palsies with petrosal bone destruction at 8 months and an ipsilateral oculomotor nerve palsy at 12 months after GKR; all palsies resolved completely with the second and third GKRs. Hypercortisolemia worsened rapidly soon after the third GKR, and the patient developed marked weight gain, hypokalemia, and hypertension. Multiple liver lesions were incidentally detected with computer tomography and identified as metastatic pituitary tumor on immunohistochemistry. An ACTH-producing adenoma should be followed carefully for early recurrence and/or metastatic spread when the tumor is an invasive macroadenoma with a high proliferation marker level. The unique aggressive behavior and high potential for malignant transformation of this case are discussed.

FDG-PET/CT findings of a metastatic pituitary tumor

The authors report the fluorodeoxyglucose (FDG)-positron emission tomography(PET)/computed tomography (CT) findings of a rare case of growth hormone-secreting pituitary carcinoma with multiple metastatic lesions to the skeleton. A 31-year-old male had presented with acromegaly and had received transsphenoidal resection of a pituitary tumor and adjuvant radiotherapy. However, the tumor recurred with local invasions and the patient underwent more resections and adjuvant chemotherapy. Several months later, the patient developed rising levels of insulin-like growth factor 1 and whole-body FDG-PET/CT scanning revealed multiple hypermetabolic lesions throughout the skeleton compatible with metastasis.

Malignant pituitary corticotroph adenomas: report of two cases and a comprehensive review of the literature

Corticotroph pituitary carcinomas are tumors, defined by the presence of distant metastases that determine their poor prognosis. The diagnosis and therapy of malignant corticotroph adenomas remains a clinical challenge. The molecular mechanisms of malignant transformation of pituitary adenomas are unclear, although they are believed to arise in an adenoma-to-carcinoma sequence. We describe two cases of malignant Cushing's disease with metastases in liver and bone, respectively. The primary pituitary tumors were treated by a combination of radiotherapy and transsphenoidal surgery, but recurred several times in both patients. The time interval between the diagnosis of Cushing's disease and the discovery of metastases was 32 and 17 years, respectively. In the first case the patient died within 6 months after diagnosis of metastasis, whereas the second patient is alive at a follow-up of 2 years after the discovery of the metastasis. Furthermore, we reviewed all available cases of corticotroph pituitary carcinomas reported in the literature and analyzed their clinical features and therapeutical management. In conclusion, frequent relapses of Cushing's disease, aggressive growth of macroadenoma, Nelson's syndrome after adrenalectomy or persistently high ACTH levels should prompt the clinician to consider the possibility of pituitary corticotroph carcinomas.

Transformation of a pituitary macroadenoma into to a corticotropin-secreting carcinoma over 16 years

OBJECTIVE

To describe a case of a pituitary macroadenoma that differentiated into a corticotropin (ACTH)-secreting carcinoma with metastasis to the thigh.

METHODS

We present a case report with a 16-year follow-up that includes anatomic and endocrine documentation of the history of an ACTH-secreting carcinoma.

RESULTS

A 32-year-old woman presented for evaluation in 1989 because of visual field defects. Magnetic resonance imaging revealed a locally invasive 3-cm macroadenoma. She had no clinical signs of cortisol excess. The patient underwent surgical debulking followed by a course of radiation directed to the pituitary. Results from retrospective immunohistochemical staining with antibodies against ACTH, prolactin, and MIB-1 were negative. Postoperatively, she could not be weaned from exogenous steroids without developing symptoms of adrenal insufficiency. In 1995, she developed left facial palsy and diplopia caused by tumor growth. In 1997, the patient developed progressive symptoms of cortisol excess, which continued after exogenous steroid replacement was discontinued. The patient's clinical status continued to deteriorate because of local mass effect from tumor growth and uncontrolled hypercortisolism. She underwent bilateral adrenalectomy in 2003. The patient remained debilitated in a long-term care facility for 2 years when she was found to have a mass on her left hip. Biopsy results of the obturator muscle revealed metastatic tumor of neuroendocrine origin with strong reactivity to ACTH antibodies and MIB-1 labeling in 8% of tumor cell nuclei.

CONCLUSION

A pituitary tumor can transform into an ACTH-secreting carcinoma in an indolent manner. Patients with invasive pituitary adenomas require long-term surveillance to monitor for differentiation into pituitary carcinoma.

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.

The medical management of Cushing's syndrome

Cushing's syndrome results from prolonged exposure to excessive circulating glucocorticosteroids, and is associated with significant morbidity and mortality. While the treatment of choice in most patients is surgical, the metabolic consequences of the syndrome, including increased tissue fragility, poor wound healing, hypertension, and diabetes mellitus, increase the risks of such surgery. The hypercortisolemia and its sequelae can be efficiently reversed using medical therapy, either as a temporary measure prior to definitive treatment, or longer term in more difficult cases. Drug treatment has been targeted at the hypothalamic/pituitary level, the adrenal glands, and also at the glucocorticoid receptor level. In this review we discuss the pharmacotherapeutic agents that have been used in Cushing's syndrome, and their efficacy, the monitoring of treatment, and potential therapies that may prove useful in the future in this complex endocrinological disorder.

Pituitary carcinoma: report of an exceptional case and review of the literature

Pituitary carcinomas are exceptional tumors and constitute 0.1 to 0.2% of pituitary tumors. Their definition includes well-established criteria but distant metastasis is the hallmark required for diagnosis. We report the fourth case of gonadotropic pituitary carcinoma described in the literature. This case illustrates the dramatic outcome of these tumors. The most interesting feature of our case was the loss of differentiation with time, established by retrospective analysis of the primary tumor surgically treated 15 years earlier. Most of the previously reported cases exhibited a majority of adrenocoticotropin and non-functioning pituitary tumors. However, the frequency of non-functioning tumors seems smaller than previously believed. In the discussion, we stress the need to detect these very aggressive tumors as early as possible and identify treatments to improve the dramatic course of these carcinomas.