Discrepant serum and urine β-hCG results due to production of β-hCG by a cribriform-morular variant of thyroid papillary carcinoma

Cribriform morular thyroid carcinoma: Clinicopathological and molecular basis for both a preventive and therapeutic approach for a rare tumor (Review)

Cribriform morular thyroid carcinoma (CMTC) has been included within the group of thyroid tumors of uncertain histogenesis in the recent World Health Organization classification of endocrine tumors. Most CMTCs occur in young euthyroid women with multiple (and bilateral) thyroid nodules in cases associated with familial adenomatous polyposis (FAP) or as single nodules in sporadic cases. CMTC generally behaves indolently, while aggressiveness and mortality are associated with high‑grade CMTC. This tumor histologically displays a distinctive combination of growth patterns with morular structures. Strong diffuse nuclear and cytoplasmic immunostaining for β‑catenin is the hallmark of CMTC. Tumor cells are also positive for thyroid transcription factor‑1 and for estrogen and progesterone receptors, but negative for thyroglobulin and calcitonin. It is possible that the CMTC phenotype could result from blockage in the terminal/follicular differentiation of follicular cells (or their precursor cells) secondary to the permanent activation of the Wnt/β‑catenin pathway. In CMTC, the activation of the Wnt/β‑catenin pathway is the central pathogenetic event, which in FAP‑associated cases results from germline mutations of the APC regulator of WNT signaling pathway (APC) gene, and in sporadic cases from somatic inactivating mutations in the APC, AXIN1 and CTNNB1 genes. Estrogens appear to play a tumor‑promoting role by stimulating both the PI3K/AKT/mTOR and the RAS/RAF/MAPK signaling pathways. Additional somatic mutations (i.e. RET rearrangements, or KRAS, phosphatidylinositol‑4,5‑bisphosphate 3‑kinase catalytic subunit α, telomerase reverse transcriptase or tumor protein 53 mutations) may further potentiate the development and progression of CMTC. While hemithyroidectomy would be the treatment of choice for sporadic cases without high‑risk data, total thyroidectomy would be indicated in FAP‑associated cases. There is insufficient clinical data to propose therapies targeting the Wnt/β‑catenin pathway, but multikinase or selective inhibitors could be used in a manner analogous to that of conventional thyroid tumors. It is also unknown whether adjuvant antiestrogenic therapy could be useful in the subgroup of women undergoing surgery with high‑risk CMTC, as well as when there is tumor recurrence and/or metastasis.

Impact of pregnancy on papillary thyroid carcinoma prognosis

Introduction

thyroid carcinoma is more frequent in women of reproductive age. It can affect both fertility and the course of pregnancy. The aim of the study was to investigate the influence of pregnancy as a factor of recurrence or progression, on the prognosis of thyroid carcinoma.

Methods

we conducted a retrospective cohort study of 117 young female patients followed up for papillary thyroid carcinoma (PTC) at the Department of Endocrinology, Diabetology and Metabolic Diseases of Ibn Rochd University Hospital of Casablanca, from January 2010 to December 2018, divided into 2 groups: group 1 composed of pregnant patients (n=42) and group 2 being the control group (n=75). Statistical analysis was made using SPSS software version 22.0.0.

Results

average age of pregnant patients was 35 ± 6.5 years old. Mean duration between first pregnancy and treatment completion was 4.4 ± 3.1 years. Over an average treatment duration of 14.4 months in postpartum, 30 patients were in remission (thyroglobulin (Tg) <1μg/l, negative thyroglobulin antibody and no morphological abnormality), while 12 had persistent symptoms (detectable Tg/thyroglobulin antibody and/or morphological abnormality). Thyroid stimulating hormone (TSH) during pregnancy was on average 0.83 mIU/l. Cancer progression was correlated with persistence of thyroid cancer to treatment before pregnancy (p = 0.01), pre-existing distant or locoregional metastases (p = 0.02) and delayed administration of radio-iodine therapy (p = 0.01). Interval between diagnosis and pregnancy, TSH level during pregnancy or the pre-conception thyroglobulin level did not have a statistically significant impact. Pregnancy was not associated with progression or recurrence of thyroid cancer (adjusted risk ratio 1.04, 95% confidence interval 0.91-1.32).

Conclusion

this study shows that pregnancy has no impact on recurrence or progression of thyroid cancer in patients declared in remission prior to conception.

Pitfalls in Challenging Thyroid Tumors: Emphasis on Differential Diagnosis and Ancillary Biomarkers

Thyroid pathology encompasses a heterogenous group of clinicopathological entities including rare and diagnostically challenging neoplasms. The review is focused on morphological, immunohistochemical, and molecular features of rare thyroid neoplasms that can pose diagnostic problems. The tumors are organized based on growth patterns including thyroid neoplasms with predominantly papillary, follicular, solid, and spindle cell growth pattern, as well as neoplasms with distinct cytological characteristics. A special section is also dedicated to rare thyroid tumors with peculiar patterns including thyroid carcinoma with Ewing family tumor elements and intrathyroidal thymic-related neoplasms.

Thyroid Carcinomas That Occur in Familial Adenomatous Polyposis Patients Recurrently Harbor Somatic Variants in APC, BRAF, and KTM2D

Background: Familial adenomatous polyposis (FAP) is a condition typically caused by pathogenic germline mutations in the APC gene. In addition to colon polyps, individuals with FAP have a substantially increased risk of developing papillary thyroid cancer (PTC). Little is known about the events underlying this association, and the prevalence of somatic "second-hit" mutations in APC is controversial. Methods: Whole-genome sequencing was performed on paired thyroid tumor and normal DNA from 12 FAP patients who developed PTC. Somatic mutation profiles were compared with clinical characteristics and previously sequenced sporadic PTC cases. Germline variant profiling was performed to assess the prevalence of variants in genes previously shown to have a role in PTC predisposition. Results: All 12 patients harbored germline mutations in APC, consistent with FAP. Seven patients also had somatic mutations in APC, and seven patients harbored somatic mutations in KMT2D, which encodes a lysine methyl transferase. Mutation of these genes is extremely rare in sporadic PTCs. Notably, only two of the tumors harbored the somatic BRAF p.V600E mutation, which is the most common driver mutation found in sporadic PTCs. Six tumors displayed a cribriform-morular variant of PTC (PTC-CMV) histology, and all six had somatic mutations in APC. Additionally, nine FAP-PTC patients had rare germline variants in genes that were previously associated with thyroid carcinoma. Conclusions: Our data indicate that FAP-associated PTCs typically have distinct mutations compared with sporadic PTCs. Roughly half of the thyroid cancers that arise in FAP patients have somatic "second-hits" in APC, which is associated with PTC-CMV histology. Somatic BRAF p.V600E variants also occur in some FAP patients, a novel finding. We speculate that in carriers of heterozygous pathogenic mutations of tumor suppressor genes such as APC, a cooperating second-hit somatic variant may occur in a different gene such as KTM2D or BRAF, leading to differences in phenotypes. The role of germline variance in genes other than APC (9 of the 12 patients in this series) needs further research.

False-Negative Urine Human Chorionic Gonadotropin Testing in the Clinical Laboratory

BACKGROUND

Human chorionic gonadotropin (hCG) assays are used to detect pregnancy, and urine point-of-care tests are frequently used to triage patients. Under certain conditions, urine tests can fail to detect pregnancy, which can have serious consequences for patient management.

OBJECTIVES

To understand the prevalence of different factors contributing to false-negative urinary hCG testing results at our institution.

METHODS

Clinical data for patients with negative urine hCG results and subsequent positive or equivocal serum hCG results within a 1-year period were reviewed.

RESULTS

Out of 9447 negative urine hCG results, 11 potential missed diagnoses were identified, with early gestational age as the most common factor, followed by β-core hook effects.

CONCLUSIONS

Although false-negative urine hCG test results are rare, understanding the commonly encountered reasons for inaccurate testing results can help clinical centers develop strategies to minimize risk for patients.

Pulmonary metastasis of cribriform-morular variant of thyroid carcinoma mimicking primary adenocarcinoma of the lung: A potential pitfall

Cribriform-morular variant of papillary thyroid carcinoma (CMV-TC) shows a peculiar mixture of follicular, cribriform, papillary, trabecular, and solid patterns with squamoid morules. Ocassionally, lung metastasis may be interpreted incorrectly as primary lung adenocarcinoma. We illustrate a case of pulmonary meastasis of CMV-TC mimicking a primary adenocarcinoma, 7 years after diagnosis of CMV-TC. The lung metastases may be easily missed if the pathologist is unaware of the patient's prior history and a limited immunohistochemical panel (CK7 and TTF-1) is used. The histologic and immunohistochemical (β-catenin+, ER+, PR+, TTF-1 +, and CK7+) findings were diagnostic of CMV-TC and ensured adequate treatment.

Cribriform-morular variant of thyroid carcinoma: a neoplasm with distinctive phenotype associated with the activation of the WNT/β-catenin pathway

Cribriform-morular variant of thyroid carcinoma is classically associated with familial adenomatous polyposis but, it can also occur as a sporadic neoplasm. This neoplasm is much more frequently observed in women than in men (ratio of 61:1). In familial adenomatous polyposis patients, tumors are generally multifocal and/or bilateral (multinodular appearance), whereas in the sporadic cases tumors tend to occur as single nodules. The tumors are well delimited, and characteristically show a blending of follicular, cribriform, papillary, trabecular, solid, and morular patterns. Neoplastic cells are tall or cuboidal with the occasional nuclear features of classic papillary thyroid carcinoma. The morules include cells with peculiar nuclear clearing and show positivity for CDX2 and CD10. Angioinvasion and capsular invasion have been described in about 30 and 40% of cases, respectively, with lymph node metastases in less than 10% of patients and distant metastases in 6%. Although this tumor has good prognosis, neuroendocrine and/or poor differentiation have been associated with aggressive behavior. Tumor cells can be focally positive or negative for thyroglobulin, but are always positive for TTF-1, estrogen and progesterone receptors, and negative for calcitonin and cytokeratin 20. Nuclear and cytoplasmic staining for β-catenin is the hallmark of this tumor type; this feature plays a role in fine needle aspiration biopsy. Cribriform-morular variant of thyroid carcinoma has a peculiar endodermal (intestinal-like) type phenotype, activation of the WNT/β-catenin signaling pathway, and belongs to the non-BRAF-non-RAS subtype of the molecular classification of thyroid tumors. Elevated expression of estrogen and progesterone receptors and activation of the WNT/β-catenin pathway may prove useful as putative therapeutic targets in cases that do not respond to conventional therapy. Clinicians should be alerted to the possibility of familial adenomatous polyposis when a diagnosis of cribriform-morular variant of thyroid carcinoma is made. Instead of being considered as a variant of papillary thyroid carcinoma its designation as cribriform-morular thyroid carcinoma seems more appropriate.

Pregnancy in papillary thyroid cancer survivors

OBJECTIVE

To evaluate “papillary thyroid carcinoma-pregnancy” interaction among cancer survivors.

MATERIAL AND METHODS

The clinical records of 8 pregnant women who received treatment for papillary thyroid cancer before their pregnancy were evaluated. Clinical features, pregnancy/perinatal outcomes and high-risk factors were compared with 45 controls who were randomly assigned from the institutional perinatal medicine database.

RESULTS

Patients in the cancer group were older than the control group (34.3 vs 29.8 years). The cesarean section rate was higher (62.5% vs 33.3%) and the APGAR scores at the 1^st and 5^th minutes were lower in the cancer group.

CONCLUSION

Management of pregnancies with papillary thyroid cancer treatment and follow-up requires a multidisciplinary approach with careful antenatal care and perinatal surveillance. Patients who have received papillary thyroid cancer treatment can safely undergo pregnancy.

Cribriform-morular variant of papillary thyroid carcinoma: a distinctive type of thyroid cancer

The aim of this systematic review is to study the features of cribriform-morular variant of papillary thyroid carcinoma (CMV-PTC) by analysing the 129 documented cases in the English literature. The disease occurred almost exclusively in women. The median age of presentation for CMV-PTC was 24 years. Slightly over half of the patients with CMV-PTC had familial adenomatous polyposis (FAP). CMV-PTC presented before the colonic manifestations in approximately half of the patients with FAP. Patients with FAP often have multifocal tumours in the thyroid. Microscopic examination of CMV-PTC revealed predominately cribriform and morular pattern of cancer cells with characteristic nuclear features of papillary thyroid carcinoma. Psammoma body is rare. On immunohistochemical studies, β-catenin is diffusely positive in CMV-PTC. The morular cells in CMV-PTC are strongly positive for CD10, bcl-2 and E-cadherin. Pre-operative diagnosis of CMV-PTC by fine-needle aspiration biopsy could be aided by cribriform architecture, epithelial morules and β-catenin immunostaining. Mutations of APC gene are found in the patients with CMV-PTC associated with FAP. In addition, mutations in CTNNB1, RET/PTC rearrangement and PI3K3CA mutations have been reported. BRAF mutation is negative in all CMV-PTC tested. Compared to conventional papillary thyroid carcinoma, CMV-PTC had a lower frequency of lymph node metastases at presentation (12%) and distant metastases (3%) as well as lower recurrence rates (8.5%) and patients' mortality rates (2%). To conclude, patients with CMV-PTC have distinctive clinical, pathological and molecular profiles when compared to conventional papillary thyroid carcinoma.