Familial medullary thyroid carcinoma: not a distinct entity? Genotype-phenotype correlation in a large family

BACKGROUND: Multiple endocrine neoplasia type 2A (MEN 2A) is a hereditary syndrome characterized by medullary thyroid carcinoma (MTC), pheochromocytoma, and hyperparathyroidism. Familial MTC (FMTC) is characterized by MTC only. Both MEN 2A and FMTC are caused by germline mutations of the RET proto-oncogene. PURPOSE: To assess genotype/phenotype correlations, large families have to be examined periodically over a long period using an extensive screening program. PATIENTS AND METHODS: Since 1973, we screened a large family with hereditary C cell carcinoma for MTC, pheochromocytoma, and parathyroid disease by clinical tests and imaging methods. A germline codon Cys618 to Ser mutation in the RET proto-oncogene was recently identified in this family. The disease phenotype associated with this mutation was compared with that of Cys634 mutations in some other large MEN 2A families. RESULTS: The distinct course of disease in the family described here is similar to that in other FMTC families and MEN 2A families with a Cys618 mutation of the RET gene, but clearly different from that in families with a Cys634 mutation. The frequency of pheochromocytomas and parathyroid disease is clearly lower, whereas cure rates and life expectancy are higher. However, in families with a Cys618 mutation, pheochromocytoma and parathyroid disease do occur. CONCLUSION: In FMTC families with cysteine codon mutations of the RET proto-oncogene, screening for other endocrinopathies is mandatory, since these may not be MTC-only families. Therefore, we suggest that MEN 2A families should not be subclassified into MEN 2A and FMTC, but rather according to their specific mutation in the RET protein (i.e., for this family MEN 2A RET C618S).     

Prenatal molecular diagnosis of RET proto-oncogene mutation in multiple endocrine neoplasia type 2A

We report a case of multiple endocrine neoplasia type 2A (MEN 2A) diagnosed prenatally at 16 weeks gestation. The 35-year-old mother is a MEN 2A patient. She had had three prior pregnancies: one resulted in a stillbirth; one produced a genetically unaffected boy; and the third was terminated in the first trimester owing to a diagnosis of blighted ovum. Autopsy did not reveal the cause of death of the stillborn infant, who was also found to be affected with MEN 2A by molecular study of paraffin-embedded tissue. Because of poor obstetric history and the patient's age, amniocentesis for cytogenetic and molecular studies was performed at 16 weeks' gestation during the pregnancy under discussion. As with other affected members in the mother's family, the missense mutation of TGC to TTC at codon 634 of the RET proto-oncogene was found in amniotic fluid cells. Analysis of DNA extracted from the lymphocytes of the infant's blood at birth confirmed the diagnosis. To our knowledge, this is the first report of prenatal diagnosis of MEN 2A.     

Pancreatic islet cell tumor metastasis in multiple endocrine neoplasia type 1: correlation with primary tumor size

BACKGROUND: Islet cell tumor (ICT) metastasis is one of the potentially lethal outcomes of multiple endocrine neoplasia type 1 (MEN 1). Management of ICT in patients with MEN 1 is controversial; some advocate resection based on biochemical evidence of progression, whereas others use tumor size to predict the risk of metastasis and the need for resection. This study correlates the size of primary ICT with the presence of metastases. METHODS: Forty-eight patients with MEN 1 with ICT, from 34 kindreds followed up in our multiple endocrine neoplasia program, were evaluated; 43 of the 48 have been explored for ICT. Metastases to the lymph nodes and liver were documented. RESULTS: Thirty-three percent of patients with pancreatic tumors less than 1 cm in greatest diameter had metastatic disease at surgery and in follow-up, whereas 34.8% of patients with tumors greater than 2 cm in diameter had metastases to lymph nodes or liver. The 2 patients with liver metastases each had primary tumors greater than 2 cm. Follow-up revealed subsequent metastasis in 1 patient. CONCLUSIONS: The size of primary tumors in MEN 1 does not correlate with metastatic potential. This is not a good criterion for exploration. Continued follow-up of these patients will be necessary to define the effect of operation on the course of ICT in MEN 1.     

Mutation analysis of glial cell line-derived neurotrophic factor, a ligand for an RET/coreceptor complex, in multiple endocrine neoplasia type 2 and sporadic neuroendocrine tumors

Causative germline missense mutations in the RET proto-oncogene have been associated with over 92% of families with the inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN 2). MEN 2A is characterized primarily by medullary thyroid carcinoma (MTC) and pheochromocytoma, both tumors of neural crest origin. Parathyroid hyperplasia or adenoma is also seen in MEN 2A, but rarely in MEN 2B, which has additional stigmata, including a marfanoid habitus, mucosal neuromas, and ganglioneuromatosis of the gastrointestinal tract. In familial MTC, MTC is the only lesion present. Somatic RET mutations have also been identified in a subset of sporadic MTCs, pheochromocytomas, and rarely, small cell lung cancer, but not in sporadic parathyroid hyperplasias/adenomas or other neuroendocrine tumors. Glial cell line-derived neurotrophic factor (GDNF) and its receptor molecule GDNFR-alpha, have recently been identified as members of the RET ligand binding complex. Therefore, the genes encoding both GDNF and GDNFR-alpha are excellent candidates for a role in the pathogenesis of those MEN 2 families and sporadic neuroendocrine tumors without RET mutations. No mutations were found in the coding region of GDNF in DNA samples from 9 RET mutation negative MEN 2 individuals (comprising 6 distinct families), 12 sporadic MTCs, 17 sporadic cases of parathyroid adenoma, and 10 small cell lung cancer cell lines. Therefore, we find no evidence that mutation within the coding regions of GDNF plays a role in the genesis of MEN 2 and sporadic neuroendocrine tumors.     

Poor prognosis in esophageal cancer patients with postoperative complications

We describe a 49-year-old woman with a history of metastatic renal cell carcinoma and classic signs and symptoms of left-sided cavernous sinus syndrome. Magnetic resonance imaging showed a lesion in the left cavernous sinus consistent with metastatic renal cell carcinoma. The patient received radiation therapy totaling 4,600 cGy, with complete resolution of symptoms. This represents the first case report of renal cell carcinoma metastatic to the left cavernous sinus.     

Medical care in 7 Chilean cities

Sclerosing mucoepidermoid carcinoma with eosinophilia (SMECE) is a recently recognized malignant neoplasm of the thyroid gland. Two additional cases of this condition which occurred in a 70-year-old woman and a 69-year-old woman are presented. The case of the 70-year-old woman (patient 1) is the first report of distant metastasis, besides lymph node metastasis, for this type of tumor. The patient initially presented with a thyroid mass, and the thyroid gland with surrounding cervical lymph nodes was removed. Because of focal keratin "pearl" formation, the tumor was misinterpreted as a metastatic squamous cell carcinoma to the thyroid. Approximately 4 years later, the patient developed a left supraclavicular mass and lung densities. A pathological fracture of the right humeral head followed, and the left supraclavicular mass recurred along with newly developed subcutaneous nodules on the chest wall and arm. Open lung and bone biopsies revealed metastatic SMECE, which was morphologically identical to that of the thyroid mass. The 69-year-old woman (patient 2) had, in 1983, undergone thyroidectomy with left radical neck dissection; this had been diagnosed as follicular carcinoma of the thyroid with lymph node involvement. After multiple isolated lymph nodes metastases, the patient developed locally extensive, recurrent tumor that showed microscopic features of SMECE. Review of the previous thyroid tumor and lymph nodes revealed the same type of histology. To our knowledge, only a single report containing eight cases of this distinctive carcinoma of the thyroid has been published. Herein we describe characteristic morphological features of two additional cases of this rare malignancy, one with distant metastasis, and we review the related literature.     

Surgical management of primary hyperparathyroidism in multiple endocrine neoplasia types 1 and 2

BACKGROUND: The surgical management of primary hyperparathyroidism in multiple endocrine neoplasia type 1 (MEN 1) remains controversial. In addition, the rarity of MEN 2A-related hyperparathyroidism has not allowed for a separate strategy for this condition. This study examines our surgical experience with MEN 1- and MEN 2A-related hyperparathyroidism and attempts to define a rational therapeutic approach to each. METHODS: Between 1970 and 1991, 124 patients underwent surgery for MEN-related hyperparathyroidism at our institution. Primary cervical explorations were performed in 84 patients with MEN 1 and 18 with MEN 2A. An additional 22 patients with MEN 1 underwent reoperative surgery. All patients with MEN 2A underwent concomitant thyroidectomy for medullary thyroid cancer. RESULTS: Compared with patients with MEN 1, patients with MEN 2A, had a lower preoperative serum Ca2+ level and fewer symptoms or complications of hypercalcemia. Multiple gland disease was evident in 90% and 83%, respectively, of patients with MEN 1 and MEN 2A. Primary explorations in patients with MEN 1 resulted in surgical cure in 94%, persistent hypercalcemia occurring in no patient undergoing subtotal resection compared with 17% of patients in whom more conservative resections were performed (p = 0.005). In patients with MEN 1, 10-year recurrence of hypercalcemia was 16% for primary explorations and 30% for reoperative procedures. In contrast, all patients with MEN 2A, whether treated by total, subtotal, or lesser resections, were cured after surgery and none had recurrence during a median follow-up of 5.8 years. CONCLUSIONS: In MEN 1 the surgical principles should be (1) identification of all four glands, (2) subtotal resection to ensure cure and facilitate possible reoperation, and (3) excision of supernumerary thymic glands. In MEN 2A we should identify and resect all enlarged glands for cure, but routine subtotal resection need not be performed because this condition is readily cured and recurrence is rare.     

The RET gene in thyroid pathology]

The RET proto-oncogene encodes a receptor tyrosine kinase which plays a crucial role during the embryonic development of the enteric nervous system and of the kidney. Cytogenetic analyses of papillary thyroid carcinoma (PTC), a neoplasm which originates from thyrocytes, have revealed that somatic rearrangements of the RET gene are involved in the etiology of a significant proportion of this tumour. Medullary thyroid carcinoma (MTC) which arises from neural-crest derived C-cells is the cardinal disease feature of multiple endocrine neoplasia type 2 (MEN 2), a dominantly inherited cancer syndrome. Recent studies have provided evidence that germline mutations of the RET gene are the underlying genetic events responsible for MEN 2. This review focuses on the role of RET mutations in the pathogenesis of PTC and MTC and summarizes our present knowledge on the consequences of these alterations on the RET tyrosine kinase function. We further describe a transgenic mouse model for hereditary MTC. Mice carrying a MEN 2A allele of RET under the control of the CGRP/calcitonin promoter develop bilateral and multifocal MTC, morphologically and biologically similar to human MTC.     

A complex nine base pair deletion in RET exon 11 common in sporadic medullary thyroid carcinoma

Genetic alteration of the RET proto-oncogene is associated with multiple endocrine neoplasia type 2A and 2B (MEN 2A and MEN 2B), familial medullary thyroid carcinoma (FMTC) and Hirschprung's disease. Oncogenically activated RET has also been demonstrated in sporadic medullary thyroid tumors, which in some cases show somatic missense mutations. We have recently described a complex 9 bp deletion in RET exon 11 in a single case of sporadic MTC. In order to determine the prevalence of this mutation among sporadic MTC tumors, we have now analysed 15 cases and five normal controls by PCR-based nonradioactive single-strand conformational polymorphism analysis (PCR-SSCP) and fragment size analysis of exon 11. DNA was extracted from microdissected tumor tissue or normal cells and subjected to nested PCR prior to analysis. A markedly divergent SSCP pattern and a PCR fragment 9 bp shorter than normal were demonstrated in 14 of the 15 MTC tumors. Sequencing revealed the deletion of nine bases encompassing a key cysteine at codon 634, often altered in MEN 2A. Four lymphocyte controls and normal thyroid tissue from one patient failed to show the deletion. Several factors in the DNA sequence environment immediately surrounding the deletions, including an extended inverted repeat, several direct repeats and a so-called symmetric element suggest that the deletional events may be non-random.     

MEN1 gene analysis in sporadic adrenocortical neoplasms

Adrenocortical tumors occur as sporadic tumors, as part of the multiple endocrine neoplasia type 1 (MEN1) syndrome or as part of other hereditary disorders. We recently cloned the MEN1 gene, a tumor-suppressor gene located on chromosome 11q13. Subsequently, we showed that sequential somatic inactivation of both alleles of the MEN1 gene contributes to the development of some sporadic endocrine neoplasms (parathyroid, enteropancreatic neuroendocrine, bronchial carcinoid, and pituitary tumors). We now studied whether somatic inactivation of the MEN1 gene contributes to the pathogenesis of sporadic adrenocortical neoplasms. Seven adrenocortical carcinomas, 2 adrenocortical carcinoma cell lines, and 11 aldosterone-secreting, 8 cortisol-secreting, and 5 nonsecreting benign adrenocortical tumors were studied. Seven tumors (5 of 5 carcinomas, 2 of 21 nonsecreting benign adenomas; P < 0.001) exhibited loss of heterozygosity on 11q13. All 33 tumors and cell lines were screened for mutation throughout the MEN1 open-reading frame and adjacent splice junctions. None exhibited a mutation within the MEN1-coding region. We conclude that somatic MEN1 mutation within the MEN1-coding region does not occur commonly in sporadic adrenocortical tumors, although the majority of adrenocortical carcinomas exhibit 11q13 loss of heterozygosity.     

Germline dinucleotide mutation in codon 883 of the RET proto-oncogene in multiple endocrine neoplasia type 2B without codon 918 mutation

The autosomal dominant multiple endocrine neoplasia type 2 syndromes (MEN 2) comprise three clinically distinct entities, MEN 2A, familial medullary thyroid carcinoma and MEN 2B, which share a common clinical feature: medullary thyroid carcinoma (MTC). MEN 2B is considered to have the most aggressive form of MTC. Therefore, early detection of MEN 2B in order to prevent potentially lethal MTC is important. More than 95% of all MEN 2B cases are caused by germline mutation at codon 918 (M918T) in exon 16 of the RET proto-oncogene. In this study, we demonstrate the presence of germline codon 883 mutation (A883F) in 2 of 3 unrelated MEN 2B cases without codon 918 mutation. Our data demonstrate a novel etiologic event which may have roles in predisposition to MEN 2B when present in the germline and in the pathogenesis of sporadic MTC when somatic.     

Cholecystitis, cholelithiasis, and ganglioneuromatosis of the gall bladder: an unusual presentation of MEN type 2b

A 40 year old man with multiple endocrine neoplasia type 2b (MEN 2b) presented with cholecystitis caused by gall stones. Twenty four years earlier, he had had a partial thyroidectomy for a cold nodule. At his initial presentation MEN 2b with medullary carcinoma of the thyroid had not been made. This was diagnosed while investigating his gall bladder symptoms and he was found to have asymptomatic residual medullary thyroid carcinoma and bilateral adrenal phaeochromocytomas. The cholecystectomy specimen contained several mixed calculi and extensive ganglioneuromatosis with large, prominent nerves containing ganglion cells in the gall bladder wall.     

Prophylactic thyroidectomy for medullary thyroid carcinoma in gene carriers of MEN2 syndrome

BACKGROUND/PURPOSE: Although medullary thyroid carcinoma (MTC) can occur sporadically, in the pediatric population it is most often associated with the multiple endocrine neoplasia syndrome (MEN type 2). Traditional screening was based on evaluation of basal and stimulated serum calcitonin levels. The recent cloning of the MEN2 gene on the RET proto-oncogene of chromosome 10 now allows for testing of gene carrier status in individuals at risk who could benefit from prophylactic treatment. The current study was undertaken to determine the appropriate age for safe total prophylactic thyroidectomy. METHODS: Over a 16-year period, 12 patients with a family history of MEN2A and one with a MEN2B underwent total thyroidectomy and central neck dissection without parathyroid autotransplantation. Four patients (31%) were treated previously for Hirschsprung's disease. RESULTS: In seven patients (mean age, 11.8 years) undergoing biochemical screening for diagnosis, multifocal MTC and C cell hyperplasia (CCH) were found in all the resected specimens. Of six patients identified with genetic screening (mean age, 9.1 years), two had elevated stimulated calcitonin levels, one (age 14) had evidence of MTC, and one (age 6) had CCH. Four patients with normal calcitonin levels had no evidence of MTC (ages 6, 8, 10) but there was one occurrence of CCH (age 11). No permanent postoperative hypoparathyroidism or recurrent laryngeal nerve damage occurred in this series. With a mean follow-up of 4 years (range, 1 to 14 years), the overall disease-free survival is 100%. CONCLUSIONS: From this study the authors conclude that total thyroidectomy can be performed safely in children and should be the treatment of choice in patients with a family history of MEN2A carrying a germinal RET mutation even if the serum basal or stimulated serum calcitonin level is normal. Total thyroidectomy should be performed as early as 5 years of age before the occurrence of CCH or MTC.     

Multiple cutaneous metastases as the first sign of lung cancer in a patient with well-differentiated papillary transitional cell carcinoma of the urinary bladder

A case of multiple, cutaneous metastases as the first sign of lung cancer in a patient with well-differentiated, papillary, transitional cell carcinoma of the urinary bladder is presented. In the left clavicular region were two, sharply demarcated, dark red tumors measuring 3 and 2 cm in diameter with a history of rapid growth and intermittent spontaneous bleeding. Thorough examination of the patient revealed 16 additional skin lesions, which were dark red macules and papules, 2-3 mm in diameter, situated on the left side of the chest. The skin biopsy material (tumors, macular and papular lesions) was studied using histological and immunohistochemical techniques and showed intact epidermis and massive dermal and subcutaneous metastatic involvement by a small cell carcinoma with neuroendocrine differentiation most likely originating in the lung.     

Adenoid cystic carcinoma of the submandibular gland with symptomatic ovarian metastases

We report the clinical and pathologic features of an adenoid cystic carcinoma of the submandibular gland that metastasized to the ovaries 10 years after initial presentation. A 30-year-old woman underwent excision of a right submandibular adenoid cystic carcinoma followed by regional external beam radiation therapy. Three years later, she underwent extended hepatic resection and localized radiotherapy to the hepatic region for metastatic disease. The patient was without evidence of disease for 7 years when she developed pelvic pain and a pelvic mass was found. A solid and cystic 10-cm left ovarian mass and a single metastatic tumor nodule involving the right ovary were excised via the laparoscope. Histologically, the tumor was identical to the patient's initial salivary gland neoplasm. The neoplastic cells were CAM 5.2 positive, S100 positive, muscle-specific actin positive, and smooth muscle actin positive. Ultrastructurally, characteristic pseudocysts (pseudolumina) with abundant basal lamina and true glandular lumina lined by short microvilli were present. Other than a single anecdotal account of a parotid gland adenoid cystic carcinoma, this case represents the first documented report of an adenoid cystic carcinoma of salivary gland origin that was associated with symptomatic ovarian metastases. This case demonstrates that the ovary is a potential site for metastatic disease many years following the diagnosis and treatment for a primary neoplasm however uncommon or remote the site of origin. Since metastatic adenoid cystic carcinoma can rarely present as an ovarian mass, a clinical history of this neoplasm should be heavily weighed in the differential diagnosis of any unusual ovarian tumor with a predominant cribriform, trabecular, or tubular pattern.     

A novel point mutation in the intracellular domain of the ret protooncogene in a family with medullary thyroid carcinoma

Specific mutations in the ret protooncogene have been found associated with multiple endocrine neoplasia type 2A (MEN 2A) and type 2B (MEN 2B) and familial medullary thyroid carcinoma (FMTC). Mutations in one of five cysteine residues in the extracellular domain have been found in over 95% of families with MEN 2A and 88% of families with FMTC. In MEN 2B patients, a specific mutation at codon 918, substituting a threonine for a methionine, has been found in 95% of cases. In FMTC, in addition to the mutations of the extracellular cysteines, three intracellular base pair changes have been reported at codons 768 and 804. Here we describe a novel intracellular mutation in exon 15 of the ret gene that leads to the substitution of an alanine for a serine at codon 891 in a family with medullary thyroid carcinoma. This amino acid change may be important in determining substrate specificity or, alternatively, may play a role in ATP binding.     

Effect of disinfectants on the bond strength of composite to dentin

The article describes ultrasonographic (US), computed tomographic (CT), 99mTc-MIBI and angiographic findings of 16 cases of multiple endocrine neoplasia (MEN) confirmed by operations and pathological examinations. Hyperparathyroidism either was the first manifestation of MEN I or was diagnosed simultaneously with other tumors. Medullary thyroid carcinoma usually developed first or coincided with pheochromocytoma in MEN I. Regular US and CT screening can lead to the detection of new endocrine neoplasia. The authors consider that US and CT are the best imaging methods for MEN.     

Myositis associated with interleukin-2 therapy in a patient with metastatic renal cell carcinoma

BACKGROUND: Interleukin-2 (IL-2) has been used successfully in the treatment of some patients with metastatic renal cell carcinoma and melanoma, with a partial response rate of 15%-20%. It produces a well documented spectrum of side effects. Autoimmune diseases have been associated with IL-2 immunotherapy and the development of autoimmune thyroiditis may correlate with antitumor clinical response. METHODS: A patient with metastatic renal cell carcinoma is described who developed a polymyositis-like myopathy after an autologous tumor vaccine and IL-2 therapy. RESULTS: The patient had a delayed response for 15 months after developing this previously unreported toxicity. CONCLUSIONS: To the authors' knowledge, this represents the first reported case of necrotizing myositis in association with IL-2 therapy. Subsequent continuous partial response of the advanced malignancy was observed for 15 months. In this case, IL-2 may have broken tolerance to both normal muscle cells and tumor cells.     

Characterization of ret oncogenic activation in MEN2 inherited cancer syndromes

Germline mutations of c-ret, encoding a receptor-type tyrosine kinase, were found to be associated with variants of multiple endocrine neoplasia type 2 (MEN2A, MEN2B), and familial medullary thyroid carcinoma. NIH/3T3 stable transfectants expressing RET with a mutation of MEN2A (MEN2A/RET) or MEN2B (MEN2B/RET) gained a transformed morphology, formed colonies in soft agar, and formed tumors in nude mice. These results confirmed that both MEN2A/RET and MEN2B/RET exert dominant transforming activities in NIH/3T3 cells. However, in contrast to their clinical manifestation, transfectants expressing MEN2A/RET exhibited a higher tumorigenicity in nude mice than transfectants expressing MEN2B/RET may depend on the presence of its ligand and/or substrates that are absent in NIH/3T3 cells. No change in the cellular localization of the mutated RET proteins was observed compared to c-RET. Interestingly, ret activation in NIT/3T3 cells appeared to be associated with up-regulation of homologous gap-junctional intercellular communication and increased expression of a gap-junctional protein, connexin43.     

Predictors of outcome of forefoot surgery for ulceration and gangrene

Desmoid tumors are fibrotic neoplasms of low metastatic potential. These tumors have long been associated with major laparotomy incisions. However, to the best of our knowledge, they have not been previously associated with laparoscopic trocar placement. This report involves the case of a patient who developed a desmoid tumor at a trocar site. A 35 year-old premenopausal woman presented with an enlarging infraumbilical mass 10 years after a laparoscopic tubal ligation. The mass was immediately subjacent to the skin incision for the laparoscopic procedure. It was approximately 6 cm in diameter and fixed to the underlying abdominal wall. It was evaluated with sonographic and CT imaging, which revealed a solid mass arising from the fascia with no associated hernia. A biopsy of the mass confirmed a diagnosis of a desmoid tumor. This was subsequently excised with a wide margin and reconstructed with Marlex mesh. The patient is without recurrence 2 years following surgery. This case represents what we believe to be the first report of a desmoid tumor arising from a incision made for the placement of a laparoscopic port. Rapidly increasing laparoscopic applications make it likely that these lesions will increase in frequency. In this setting, resection with wide margins remains the mainstay of treatment for desmoid tumors.