Ovarian tumors associated with multiple endocrine neoplasias and related syndromes (Carney complex, Peutz-Jeghers syndrome, von Hippel-Lindau disease, Cowden's disease)

Gastric-phenotype Mucinous Carcinoma of the Fallopian Tube with Secondary Ovarian Involvement in a Woman with Peutz-Jeghers Syndrome: A Case Report

Peutz-Jeghers syndrome is an autosomal dominant condition characterized by the association of hamartomatous polyps in the digestive tract, mucocutaneous pigmentation, family history, and infrequently tumors of the female genital tract with one of the most characteristic being the gastric-type endocervical adenocarcinoma. We present the case of a 75-year-old woman with a history of gastrointestinal polyps and cancer of the pancreas and breast, diagnosed with Peutz-Jeghers syndrome, who clinically debuted with a primary adnexal tumor. However, on histologic examination it was found to be a gastric-phenotype primary mucinous carcinoma tubal in origin, associated to tubal mucinous metaplasia and secondary ovarian involvement. One of her daughters had a confirmed genetic diagnosis of Peutz-Jeghers syndrome and presented with mucinous metaplasia of the tubal mucosa in the pathological study of a prophylactic hysterectomy specimen. Another of her daughters died from an ovarian juvenile granulosa cell tumor, she did not have a genetic diagnosis of Peutz-Jeghers syndrome. This case intends to highlight the rarity of gastrointestinal-type mucinous carcinomas of the ovary and fallopian tube (similar to gastric-type endocervical adenocarcinoma) in Peutz-Jeghers syndrome and emphasize the importance of genetic counseling of these patients as well as the adequate sampling of surgical specimens for early detection and treatment.

Cystic ovarian teratoma as a novel tumor and growth hormone deficiency as new conditions presenting in Multiple Endocrine Neoplasia type 2B: Case reports and review of the literature

BACKGROUND

We describe early and typical nonendocrine symptoms of Multiple Endocrine Neoplasia type 2B (MEN2B) presented in our patients with de novo M918T mutation in the RET proto-oncogene in early childhood, however, the diagnosis of MEN2B and medullary thyroid carcinoma (MTC) was confirmed late, in the second decade of life. In this paper, we emphasize the possibility of growth retardation, growth hormone (GH) deficiency and ovarian teratoma as a new symptom of MEN2B.

CASE REPORTS

Advanced MTC with palpable mass on the neck and nonendocrine symptoms such as marfanoid habitus, thickened lips, mucosal neuromas led to the diagnosis in case 1 at the age of 13 years and GH deficiency and nonendocrine symptoms in case 2 at the age of 11 years. The earliest feature of MEN2B was alacrima and constipation. Patient 1 was operated on for a slipped femoral capital epiphysis and for a cystic ovarian teratoma.

CONCLUSIONS

Improved awareness of nonendocrine signs of MEN2B could lead to earlier diagnosis, when surgical cure of MTC is possible. Alacrima is the first sign of MEN2B. We confirmed the possibility of growth retardation and GH deficiency in MEN2B, which had been previously rarely described. We suggest that patients with MEN2B may develop cystic ovarian teratoma, to the best of our knowledge, which has never been described so far in the literature. The results of this study could be used to guide further diagnosing of MENB2 at the early stage for better clinical outcome. We emphasize that MEN2B carries a risk for development of cystic ovarian teratoma as a novel tumor in this disease.

Metachronous ovarian endometrioid carcinomas in a patient with a PTEN variant: case report of incidentally detected Cowden syndrome

Background

Somatic PTEN mutation occurs in a proportion of ovarian endometrioid carcinomas. However, these cancers have seldom been reported in diseases associated with germline PTEN variants, such as Cowden syndrome (CS).

Case presentation

The present case was a 39-year-old woman with a left ovarian carcinoma who demonstrated a germline splice variant of PTEN (c.1026 + 1G > T) following genome-wide whole exome sequencing of her germline DNA. Histology of her resected tumor revealed endometrioid carcinoma of the same type as a right ovarian cancer resected eight years previously. These tumors showed null immunostaining for PTEN. She was genetically diagnosed with CS. Despite her clinical examinations had demonstrated several characteristic findings of CS, including mammary fibroma, esophageal and skin papilloma, colonic hamartoma, uterine myoma, and lipoma, the clinicians could not approach this diagnosis.

Conclusion

Ovarian endometrioid carcinoma is generally thought to develop from endometrial tissue menstruated from the uterus and implanted on the ovary. To date, ovarian cancers have not been listed as CS-related cancers; however, ovarian endometrioid cancer can have a potential association with CS in endometriosis cases.

Carney complex: A familial lentiginosis predisposing to a variety of tumors

Carney complex is a familial lentiginosis syndrome; these disorders cover a wide phenotypic spectrum ranging from a benign inherited predisposition to develop cutaneous spots not associated with systemic disease to associations with several syndromes. Carney complex is caused by PRKAR1A mutations and perturbations of the cyclic AMP-dependent protein kinase (PKA) signaling pathway. In addition to the cutaneous findings, the main tumors associated with Carney complex are endocrine: 1) primary pigmented nodular adrenocortical disease, a bilateral adrenal hyperplasia leading to Cushing syndrome; 2) growth-hormone secreting pituitary adenoma or pituitary somatotropic hyperplasia leading to acromegaly; 3) thyroid and gonadal tumors, including a predisposition to thyroid cancer. Other tumors associated with Carney complex include: 1) myxomas of the heart, breast and other sites; 2) psamommatous melanotic schwannomas which can become malignant; 4) a predisposition to a variety of cancers.

Do hereditary syndrome-related gynecologic cancers have any specific features?

Abstract

Hereditary syndromes are responsible for 10 % of gynaecologic cancers, among which hereditary breast-ovarian cancer and hereditary non-polyposis colon cancer syndromes, known as HBOC and Lynch syndromes respectively, present the highest relative risk. The latter predisposes to endometrial cancer and both contribute to ovarian cancer. Cowden syndrome-related endometrial cancer and the increased risk of ovarian, uterine and cervical cancers associated with Peutz-Jeghers syndrome, are also demonstrated, while Li-Fraumeni syndrome patients are prone to develop ovarian and endometrial cancers. Despite these syndromes’ susceptibility to gynaecologic cancers being consensual, it is still not clear whether these tumours have any epidemiologic, clinical, pathologic or imaging specific features that could allow any of the intervening physicians to raise suspicion of a hereditary syndrome in patients without known genetic risk. Moreover, controversy exists regarding both screening and surveillance schemes. Our literature review provides an updated perspective on the evidence-based specific features of tumours related to each of these syndromes as well as on the most accepted screening and surveillance guidelines. In addition, some illustrative cases are presented.

Teaching Points

• HBOC syndrome is mainly associated with ovarian HGSC, which arises in fallopian fimbriae.

• LS-related endometrial tumours show histological diversity and predilection for lower uterine segment.

• LS and CS-related ovarian cancers are mostly of non-serous type, usually endometrioid.

• Ovarian SCTAT and cervical adenoma malignum are strongly associated with PJS.

• Unfortunately, hereditary gynaecologic cancers do not seem to have distinctive imaging features.

Medical and Surgical Management of Carney Complex

Carney complex is a rare, autosomal dominant genetic disorder that consists of multiple myxomatous lesions and endocrine abnormalities, including skin lesions, cardiac myxomas, primary pigmented nodular adrenocortical disease, and acromegaly. This review discusses the medical and surgical treatment of patients with Carney complex.

Preservation of fertility in non-Peutz-Jegher syndrome-associated ovarian sex cord tumour with annular tubules

We report the successful conservative management of a non-Peutz-Jegher syndrome-associated ovarian sex cord tumour with annular tubules in a 32-year-old patient. The patient underwent a unilateral salpingo-oophorectomy by laparoscopy, and conceived spontaneously approximately 6 months after the diagnosis. After a normal term pregnancy, she underwent a contralateral laparoscopic salpingo-oophorectomy with hysterectomy. The patient is now on hormone replacement therapy and, after 30 months of follow-up, continues to present no sign of disease recurrence.

Cancer problem in Peutz-Jeghers syndrome

Peutz–Jeghers syndrome is a rare autosomal dominantly inherited condition, characterized by the presence of hamartomatous gastrointestinal polyps and mucocutaneous pigmentation. Patients with this syndrome can be associated with other neoplasms such as ovarian neoplasms known as sex-cord tumor with annular tubules that are associated in one third of the cases with this syndrome and other types of malignancies. We report a 42-year-old woman with a history of Peutz–Jeghers Syndrome and bilateral breast cancer that presented with abnormal uterine bleeding. Total abdominal hysterectomy with bilateral salpino-oophorectomy was done and an ovarian sex cord tumor with annular tubules was incidentally diagnosed. By reviewing literatures and in agreement with previous studies we suggest routine screening for malignancies in patients with Peutz–Jeghers syndrome.

The complex of myxomas, spotty skin pigmentation and endocrine overactivity (Carney complex): imaging findings with clinical and pathological correlation

The complex of myxomas, spotty skin pigmentation and endocrine overactivity, or Carney complex (CNC), is a familial multiple endocrine neoplasia and lentiginosis syndrome. CNC is inherited in an autosomal dominant manner and is genetically heterogeneous. Its features overlap those of McCune-Albright syndrome and other multiple endocrine neoplasia (MEN) syndromes. Spotty skin pigmentation is the major clinical manifestation of the syndrome, followed by multicentric heart myxomas, which occur at a young age and are the lethal component of the disease. Myxomas may also occur on the skin (eyelid, external ear canal and nipple) and the breast. Breast myxomas, when present, are multiple and bilateral among female CNC patients, an entity which is also described as “breast-myxomatosis” and is a characteristic feature of the syndrome. Affected CNC patients often have tumours of two or more endocrine glands, including primary pigmented nodular adrenocortical disease (PPNAD), an adrenocorticotropin hormone (ACTH)-independent cause of Cushing’s syndrome, growth hormone (GH)-secreting and prolactin (PRL)-secreting pituitary adenomas, thyroid adenomas or carcinomas, testicular neoplasms (large-cell calcifying Sertoli cell tumours [LCCSCT]) and ovarian lesions (cysts and cancinomas). Additional infrequent but characteristic manifestations of CNC are psammomatous melanotic schwannomas (PMS), breast ductal adenomas (DAs) with tubular features, and osteochondromyxomas or “Carney bone tumour”.

Teaching Points

• Almost 60 % of the known CNC kindreds have a germline inactivating mutations in the PRKAR1A gene.

• Spotty skin pigmentation is the major clinical manifestation of CNC, followed by heart myxomas.

• Indicative imaging signs of PPNAD are contour abnormality and hypodense spots within the gland.

• Two breast tumours may present in CNC: myxoid fibroadenomas (breast myxomatosis) and ductal adenomas.

• Additional findings of CNC are psammomatous melanotic schwannomas (PMSs) and osteochondromyxomas.

Genetic predisposition to peripheral nerve neoplasia: diagnostic criteria and pathogenesis of neurofibromatoses, Carney complex, and related syndromes

Neoplasms of the peripheral nerve sheath represent essential clinical manifestations of the syndromes known as the neurofibromatoses. Although involvement of multiple organ systems, including skin, central nervous system, and skeleton, may also be conspicuous, peripheral nerve neoplasia is often the most important and frequent cause of morbidity in these patients. Clinical characteristics of neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2) have been extensively described and studied during the last century, and the identification of mutations in the NF1 and NF2 genes by contemporary molecular techniques have created a separate multidisciplinary field in genetic medicine. In schwannomatosis, the most recent addition to the neurofibromatosis group, peripheral nervous system involvement is the exclusive (or almost exclusive) clinical manifestation. Although the majority of cases of schwannomatosis are sporadic, approximately one-third occur in families and a subset of these has recently been associated with germline mutations in the tumor suppressor gene SMARCB1/INI1. Other curious syndromes that involve the peripheral nervous system are associated with predominant endocrine manifestations, and include Carney complex and MEN2b, secondary to inactivating mutations in the PRKAR1A gene in a subset, and activating mutations in RET, respectively. In this review, we provide a concise update on the diagnostic criteria, pathology and molecular pathogenesis of these enigmatic syndromes in relation to peripheral nerve sheath neoplasia.

An incidentally discovered asymptomatic para-aortic paraganglioma with Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by mucocutaneous melanin pigmentation and gastrointestinal (GI) tract hamartomatous polyps and an increased risk of malignancy. In addition to polyposis, previous studies have reported increased risk of GI and extraGI malignancies in PJS patients, compared with that of the general population. The most common extraintestinal malignancies reported in previous studies are pancreatic, breast, ovarian and testicular cancers.We report the case of a 17-year-old boy who presented with generalized weakness, recurrent sharp abdominal pain and melena, had exploratory laparotomy and ileal resection for ileo-ileal intussusception. Pigmentation of the buccal mucosa was noted. An abdominal computed tomography scan (CT) revealed multiple polyps in small bowel loops. Gastroscopy revealed multiple dimunitive polyps in stomach and pedunculated polyp in duodenum. Colonoscopy revealed multiple colonic polyps. Pathological examination of the polyps confirmed hamartomas with smooth muscle arborization, compatible with Peutz-Jeghers polyps. CT scan guided left para-aortic lymph node biopsy revealed the characteristic features of extra-adrenal para-aortic paraganglioma. Although cases of various GI and extra GI malignancies in PJS patients has been reported, the present case appears to be the first in literature in which the PJS syndrome was associated with asymptomatic extraadrenal para-aortic paraganglioma. Patients with PJS should be treated by endoscopic or surgical resection and need whole-body screening.

[Carney complex]

Carney complex (CNC) is an autosomal dominantly inherited syndrome characterized by spotty skin pigmentation, cardiac and cutaneous myxoma, and endocrine overactivity. Skin pigmentation includes lentigines and blue nevi. Myxomas may occur in breast, skin and heart. Cardiac myxomas may be multiple and occur in any cardiac chamber, and are more prone to recurrence. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD may occur isolated, with no other signs of CNC. Pituitary and thyroid glands and gonads are also involved. The PRKAR1A gene, located in 17 q22-24, encodes type 1A regulatory subunit of protein kinase A. Inactivating germline mutations of this gene are found in 70% of patients with CNC. PRKAR1A is a key component of the c-AMP signaling pathway that has been implicated in endocrine tumorigenesis. Many different mutations have been reported in the PRKAR1A gene. In almost all cases the sequence change was predicted to lead to a premature stop codon and the resultant mutant mRNA was subject to nonsense-mediated mRNA decay. There is no clear genotype-phenotype correlation in patients with CNC. Genetic analysis should be performed in all CNC index cases. All affected patients should be monitored for clinical signs of CNC at least once a year. Genetic diagnosis allows for more effective preparation of more appropriate and effective therapeutic strategies and genetic counseling for patients and gene carriers, and to avoid unnecessary tests to relatives not carrying the gene.

Clinical and molecular genetics of Carney complex

Carney complex (CNC) is a rare multiple familial neoplasia syndrome that is characterized by multiple types of skin tumors and pigmented lesions, endocrine neoplasms, myxomas and schwannomas and is inherited in an autosomal dominant manner. Clinical and pathologic diagnostic criteria are well established. Over 100 pathogenic variants in the regulatory subunit type 1A (RI-A) of the cAMP-dependent protein kinase (PRKAR1A) have been detected in approximately 60% of CNC patients, most leading to R1A haploinsufficiency. Other CNC-causing genes remain to be identified. Recent studies provided some genotype-phenotype correlations in CNC patients carrying PRKAR1A-inactivating mutations, which provide useful information for genetic counseling and/or prognosis; however, CNC remains a disease with significant clinical heterogeneity. Recent mouse and in vitro studies have shed light into how R1A haploinsufficiency causes tumors. PRKAR1A defects appear to be weak tumorigenic signals for most tissues; Wnt signaling activation and cell cycle dysregulation appear to be important mediators of the tumorigenic effect of a defective R1A.

A case of Peutz-Jeghers syndrome with breast cancer, bilateral sex cord tumor with annular tubules, and adenoma malignum caused by STK11 gene mutation

BACKGROUND

Peutz-Jeghers syndrome (PJS) is a rare autosomal dominant disorder, and women with this syndrome are at an increased risk of developing intestinal and extraintestinal malignancies including breast and gynecologic malignancies. This case report presents a patient with PJS with a concomitant breast cancer, bilateral stromal tumors with annular tubules of the ovaries, and adenoma malignum of the cervix.

CASE

A 43-year-old woman presented with an advanced-stage breast cancer and a pelvic mass. The patient was treated with neoadjuvant chemotherapy followed by laparotomy with a hysterectomy and oophorectomy. Final pathologic examination revealed a concomitant breast cancer with metastasis to the ovaries, bilateral stromal tumors with annular tubules of the ovaries, and adenoma malignum of the cervix.

CONCLUSIONS

Patients with PJS are at a high risk for intestinal and extraintestinal malignancies and can present with multiple concomitant malignancies.

Virilizing ovarian tumor in a 14-year-old female with a prior familial multinodular goiter

A 14-year-old female presented with intermittent abdominal pain, deepening of voice and amenorrhoea for 4 months. Twelve months earlier she had had a thyroidectomy because of familial multinodular goiter and had, subsequently, received substitution with L-thyroxine. At the time of admission, a high serum testosterone level was detected. The dexamethasone suppression test confirmed the hormonal autonomy and magnetic resonance imaging (MRI) visualized a solid tumor within the left ovary. The pathological diagnosis after left salpingo-oophorectomy was Sertoli-Leydig cell tumor. The patient has remained disease-free for 6 years.

Divergent myoid, neuroendocrine, and perineural differentiation in a nasal tumor of a patient with Carney complex

A 39-year-old woman with Carney complex presented with a stroke of undetermined etiology. Computed tomography showed bilateral thalamic infarctions and also an unsuspected multicompartmental cystic neoplasm that had eroded the anterior clivus and extended forward into the nasopharynx. Histologically, the mass appeared benign and was composed of spindle cells and multiple foci of striated muscle. Immunohistochemically, the spindle cells were strongly reactive for S-100 protein and to a lesser extent for CD57, collagen IV, neuron-specific enolase, smooth muscle actin, epithelial membrane antigen, and glut-1. The striated muscle cells were positive for desmin and myogenin. The MIB-1 labeling index was 0.5%. Ultrastructural examination was necessary to reveal the full extent of divergent differentiation. Ultrastructurally, the spindle cells showed divergent differentiation along several cell lines, including smooth muscle, neuroendocrine, hybrid smooth muscle-neuroendocrine, perineural-like cells, and striated muscle. The occurrence of this unique lesion in a patient with the Carney complex raises the possibility that it may be a rare component of the syndrome.

Breast cancer, ovarian gonadoblastoma and cervical cancer in a patient with Peutz-Jeghers Syndrome

BACKGROUND

Peutz-Jeghers Syndrome (PJS) is a rare autosomal dominant disorder characterized by gastrointestinal hamartomatous polyps and mucocutaneous pigmentation. Patients with PJS have increased risk for gastrointestinal, breast, and female genital tract cancers.

CASE

Multiple genital tract cancers in a 34-year-old woman with PJS are described. The patient, who was admitted to our department with severe vaginal bleeding, was performed right salpingo-oophorectomy because of pure gonadoblastoma in 1996. In 2003, concomitant to cervical carcinoma, breast cancer was diagnosed. Patient underwent left modified radical mastectomy due to the invasive papillary carcinoma. The patient received six cycles combination chemotherapy and radiation therapy because of stage IIIB cervical cancer.

CONCLUSION(S)

This is the first case report presenting PJS associated with multiple genital tract tumors including ovarian gonadoblastoma in literature. The clinical significance of these tumors in PJS patients has been reviewed.

Oral manifestations of internal malignancy and paraneoplastic syndromes

Malignant tumors of visceral organs are a fundamental feature of familial cancer and paraneoplastic syndromes. In many instances, the presence of an internal and often occult malignancy may be forewarned by various external manifestations. Several of these findings are preferentially localized to the head and neck region, including the oral cavity proper. This places the dental practitioner in a unique position to detect these "markers" of occult neoplastic involvement. Because these markers may present before an established syndrome or cancer diagnosis, even representing the first expression of disease in some cases, early recognition by a dentist may lead to timely diagnosis and management of these cancer-associated syndromes.

Three synchronized neoplasms of the female genital tract: an extraordinary presentation

INTRODUCTION

We report a case of unusual co-existence of multiple primary neoplasms of female genital tract.

CASE

A 62-year-old gravida 2, para 2 was referred with spotting and vaginal discharge for about 6 months. Fractionate curettage was performed and documented endocervical squamous cell carcinoma in situ. Subsequently total abdominal hysterectomy and bilateral salphingo-oophorectomy was performed. Final pathological report demonstrated cervical squamous cell carcinoma, right ovarian Brenner tumor, left ovarian granulosa tumor and endometrial polyps.

DISCUSSION

Multiple primary neoplasms of female genital tract is a well-recognized yet rare occurrence. Although the presented case is probably an incidental event, the pathogenesis of the neoplastic process affecting the tissues with different embryological origin needs further research and evaluation. It is important to distinguish multiple primary neoplasms from metastatic disease because of the fact that overall survival as well as treatment would vary considerably.

Carney complex: the first 20 years

PURPOSE OF REVIEW

The purpose of this review is to comment on the current findings on Carney complex, a dominantly inherited disease and a unique multiple endocrine neoplasia syndrome.

RECENT FINDINGS

Sequencing of the PRKAR1A gene in more than 150 kindreds has revealed a number of pathogenic mutations; in more than 90% of the cases, the sequence change was predicted to lead to a premature stop codon and, thus, mutant mRNAs were subject to nonsense-mediated mRNA decay. In Carney complex syndrome cells carrying these mutations, protein kinase A activity is irregularly stimulated by cAMP. Mutations that did not lead to a premature stop codon have also been described; these were also associated with abnormal protein kinase A activity. Animal models of the disease have been recently developed; they reproduced some of the stigmata of Carney complex syndrome but not all. Genetic testing of patients' family members has been introduced in recent years, leading to early detection and a better overall prognosis.

SUMMARY

New treatments have yet to be applied; the elucidation of the molecular pathways regulated by PRKAR1A holds the promise of leading to molecularly designed therapies.

Peutz-Jeghers Syndrome with multiple genital tract tumors and breast cancer: a case report with a review of literatures

We report here on the multiple genital tract neoplasms in a 41-yr-old Korean woman with Peutz-Jeghers Syndrome (PJS). The patient presented with lower abdominal pain. Her previous medical history was PJS and breast cancer. Pelvic ultrasound showed a multilocular cyst at the right adnexal region, diagnosed as bilateral ovarian mucinous borderline tumors. An ovarian sex cord tumor with annular tubules was incidentally diagnosed together with a minimal deviation adenocarcinoma of the uterine cervix and mucinous metaplasia of both the Fallopian tubal mucosa and the endometrium. Although the cases of multiple genital tract tumors with PJS has rarely been reported, the present case appears to be the first in Korea in which the PJS syndrome was complicated by multiple genital tract tumors and infiltrating carcinoma of the breast. The clinical significance of the multiple genital tract tumors and breast cancer associated with PJS is reviewed.

Carney complex: pathology and molecular genetics

Carney complex (CNC) is a unique multiple endocrine neoplasia syndrome (MIM 160980) which is characterized by unusual biochemical features (chronic hypersomatotropinemia and paradoxical responses of cortisol production to glucocorticoids) and multi-tissue involvement. The gene coding for the protein kinase A (PKA) type 1alpha regulatory subunit, PRKAR1A, had been mapped to 17q22-24, one of the genetic loci involved in CNC, and allelic analysis using probes from this chromosomal region revealed consistent changes in CNC tumors. Sequencing of the PRKAR1A gene in over 100 kindreds showed a number of mutations; in almost all cases, the sequence change was predicted to lead to a premature stop codon, and mutant mRNAs were subject to nonsense-mediated mRNA decay. In CNC cells, PKA activity assays showed increased stimulation by cAMP. Few mutations that did not lead to a premature stop codon have been described; they are also associated with increased PKA activity. PRKAR1A has been investigated in sporadic endocrine tumors; it does not appear to be mutated in pituitary adenomas, but both thyroid and adrenal neoplasms have been found to harbor somatic mutations of this gene. Animal models of the disease have been developed. CNC is the first human disease caused by mutations of one of the subunits of the PKA holoenzyme, a critical component of numerous cellular signaling systems. This has wide implications for cAMP involvement in endocrine tumorigenesis.

Accelerated onsets of gastric hamartomas and hepatic adenomas/carcinomas in Lkb1+/−p53−/− compound mutant mice

Germline mutations in the LKB1 gene are responsible for Peutz-Jeghers syndrome (PJS), which is characterized by gastrointestinal hamartomas and increasing risk of cancer. Mice with Lkb1(+/-) mutation develop gastric hamartomas after >20 weeks of age, and hepatocellular adenomas and carcinomas >30 weeks. It has been reported that, in PJS patients, carcinomas progressed from hamartomas contain p53 mutations, and that LKB1 regulates p53-dependent apoptosis. To investigate the roles of LKB1 and p53 mutations in tumorigenesis, we constructed compound mutant mice of Lkb1 and p53 genes. In the Lkb1(+/-)p53(-/-) mice, formation of gastric hamartomas and hepatic tumors was accelerated. However, histopathology of hamartomas was similar between Lkb1(+/-)p53(-/-) and Lkb1(+/-) mice, and Lkb1 genotype remained heterozygous, suggesting that the p53 mutation affected hamartoma initiation. Contrary to the heterozygous hamartomas in the stomach and duodenum, the hepatic adenomas in Lkb1(+/-)p53(-/-) mice showed loss of Lkb1 heterozygosity (LOH), suggesting that lack of p53 stimulated Lkb1 LOH and tumor initiation in the liver. Taken together, these results indicate that lack of p53 causes earlier onsets of gastric hamartomas and hepatic tumors in Lkb1(+/-)p53(-/-) mice.

Peutz-Jeghers syndrome and bilateral ovarian tumors in a 14-year-old girl

The authors describe a 14-year-old girl with Peutz-Jeghers syndrome who presented with progressive abdominal distention. Radiologic investigation revealed large polycystic tumors on both ovaries. Bilateral ovariectomy was performed and microscopic examination showed mucinous ovarian tumors. The authors discuss the increased risk for cancer in patients with the Peutz-Jeghers syndrome and review the different ovarian tumors associated with this syndrome. They also stress that these patients must be followed not only for gastrointestinal disease but also by regular gynecologic examination.

[Hereditary predispositions to gynaecological cancers]

The breast, ovary and endometrial cancers are hereditary in 5 to 10% of the cases. These genetic predisposition syndromes can be classified into two major classes: ovarian cancer and breast cancer predisposition family cases (genes BRCA1 and BRCA2) and family cases of colon cancer, endometrial cancer and ovarian cancer (Lynch syndrome or HNPCC) (genes hMLH1, hMSH2, hMLH6). The estimate of the family and individual risk can contribute in a determining manner to the management of these patients, by the practice of screening or an adapted prevention. Indeed, the risk of cancer of an individual having a positive test for a gene of predisposition to breast cancer (BRCA1, BRCA2) or to the colon cancer (hMLH1, hMSH2, hMLH6) lies between 50 and 70% at the age of 70 years. The indication of a genetic test must be discussed within the framework of an oncogenetic consultation. An individual and family medical management ranging from simple monitoring to prophylactic surgery is proposed to these predisposed people.

The lentiginoses: cutaneous markers of systemic disease and a window to new aspects of tumourigenesis

Familial lentiginosis syndromes cover a wide phenotypic spectrum ranging from a benign inherited predisposition to develop cutaneous lentigines unassociated with systemic disease, to associations with several syndromes carrying increased risk of formation of hamartomas, hyperplasias, and other neoplasms. The molecular pathways involved in the aetiology of these syndromes have recently been more clearly defined and several major cellular signalling pathways are probably involved: the protein kinase A (PKA) pathway in Carney complex (CNC), the Ras/Erk MAP kinase pathway in LEOPARD/Noonan syndromes, and the mammalian target of rapamycin pathway (mTOR) in Peutz-Jeghers syndrome and the diseases caused by PTEN mutations. Here we discuss the clinical presentation of these disorders and discuss the molecular mechanisms involved. The presence of lentigines in these diseases caused by diverse molecular defects is probably more than an associated clinical feature and likely reflects cross talk and convergence of signalling pathways of central importance to embryogenesis, neural crest differentiation, and end-organ growth and function of a broad range of tissues including those of the endocrine, reproductive, gastrointestinal, cardiac, and integument systems.

LKB1, the multitasking tumour suppressor kinase

Mutations in the lkb1 gene are found in Peutz-Jeghers syndrome (PJS), with loss of heterozygosity or somatic mutations at the lkb1 locus, suggesting the gene product, the serine/threonine kinase LKB1, may function as a tumour suppressor. Patients with PJS are at a greater risk of developing cancers of epithelial tissue origin. It is widely accepted that the presence of hamartomatous polyps in PJS does not in itself lead to the development of malignancy. The signalling mechanisms that lead to these PJS related malignancies are not well understood. However, it is evident from the recent literature that LKB1 is a multitasking kinase, with unlimited potential in orchestrating cell activity. Thus far, LKB1 has been found to play a role in chromatin remodelling, cell cycle arrest, Wnt signalling, cell polarity, and energy metabolism, all of which may require the tumour suppressor function of this kinase and/or its catalytic activity.