Macrofollicular Variant of Follicular Thyroid Carcinoma: A Rare Underappreciated Pitfall in the Diagnosis of Thyroid Carcinoma

Background: Follicular-patterned thyroid nodules predominantly composed of macrofollicular structures without nuclear atypia are generally regarded as benign (i.e., hyperplastic nodules or follicular adenomas). In line with this concept, fine-needle aspiration cytology (FNAC) also assigns a benign connotation to the presence of macrofollicular structures, unless thyrocytes present papillary thyroid carcinoma (PTC)-related nuclear features that raise the possibility of a macrofollicular variant of PTC. However, cases showing macrofollicular architecture, capsular invasion, and no PTC features can also be observed. Methods: We describe the clinical, cytological, histological, and molecular genetic features of four cases of encapsulated follicular neoplasms that presented histologically with a predominant (>70%) macrofollicular architecture, but which also showed clear signs of capsular invasion, and thus were classified as macrofollicular variant of follicular thyroid carcinoma (MV-FTC). Results: Cytologically, macrofollicular structures were identified in all cases, leading to a benign FNAC diagnosis in three of the four cases. Due to increasing nodule size, thyroidectomy was performed in all cases. Histology showed focal and limited capsular invasion, without vascular invasion. Next-generation sequencing (custom 394 gene panel) of each tumor compared with matched normal DNA revealed a total of 7 somatic variants, including dual (likely biallelic) mutations in the DICER1 gene in 2 patients. The clinical outcome was excellent in all cases. Conclusions: Similar to the classical minimally invasive follicular thyroid carcinoma, MV-FTC appears to behave indolently. MV-FTC has a high rate of false-negative FNAC results, but MV-FTC is very rare (<0.05% of all thyroidectomies) and apparently has an indolent behavior. Further studies comprising larger series are necessary to better clarify the biology of this diagnostically challenging rare tumor.

Gallbladder Mixed Neuroendocrine-Non-neuroendocrine Neoplasm (MiNEN) Arising in Intracholecystic Papillary Neoplasm: Clinicopathologic and Molecular Analysis of a Case and Review of the Literature

Mixed neuroendocrine-non-neuroendocrine neoplasms (MiNENs) of the gallbladder are generally composed of adenocarcinoma and neuroendocrine carcinoma (NEC). Rare cases associated with intracholecystic papillary neoplasm (ICPN) have been reported. Although recent molecular data suggest that the different components of digestive MiNENs originate from a common precursor stem cell, this aspect has been poorly investigated in gallbladder MiNENs. We describe the clinicopathologic and molecular features of a MiNEN composed of ICPN, adenocarcinoma, and NEC. A 66-year-old woman presented with severe abdominal pain. She underwent radical cholecystectomy and an intracholecystic mass was found. Histologically, it was composed of ICPN associated with adenocarcinoma and large cell neuroendocrine carcinoma (LCNEC). The three components were positive for DNA repair proteins and p53. EMA was positive in the ICPN and adenocarcinoma components, while it was negative in the LCNEC. Heterogeneous expression of Muc5AC, cytokeratin 20, and CDX2 was only observed in the ICPN component. Cytokeratin 7 was diffusely positive in both adenocarcinoma and LCNEC components, while it was heterogeneously expressed in the ICPN. The copy number variation analysis showed overlapping results between the adenocarcinoma and LCNEC components with some minor differences with the ICPN component. The three tumor components showed the same mutation profile including TP53 mutation c.700T > C (p. Tyr234His), without mutations in other 51 genes known to be frequently altered in cancer pathogenesis and growth. This finding may support the hypothesis of a monoclonal origin of the different tumor components. We have also performed a review of the literature on gallbladder MiNENs.

Lymph node involvement by enteropathy-like indolent NK-cell proliferation

Natural killer (NK)-cell enteropathy (NKCE) and lymphomatoid gastropathy (LG) are closely related lymphoproliferative disorders (LPDs) composed of mature and Epstein–Barr virus (EBV)-negative NK-cells. Although these uncommon and indolent lymphoid proliferations mostly arise within the gastrointestinal (GI) tract as their designations implies, a few cases have been reported outside the GI tract. We hereby describe a unique case of lymph node infiltration by such EBV-negative NK-cell proliferation fortuitously found during routine examination of a gallbladder resected for biliary lithiasis. The histologic, phenotypic, and molecular features of this NK-cell proliferation, which were very similar if not identical to those previously reported in NKCE or LG, suggest that similar indolent EBV-negative NK-cell LPDs may also occasionally involve lymph nodes.

A novel insight on chronic AlCl3 neurotoxicity through IL-6 and GFAP expressions: modulating effect of functional food fenugreek seeds

OBJECTIVE

This study was designed to review the effect of chronic aluminium exposure on interleukin-6 (IL-6) secretion in the posterior brain and test the putative modulating effect of fenugreek seeds.

METHODS

Female Wistar rats were divided into four groups: control; AlCl3 during 5 months (500 mg/kg body weight, intragastric for 1 month then 1600 ppm via the drinking water); AlCl3 plus fenugreek seed powder (FSP) (5%) during the last 2 months and FSP alone.

RESULTS

Oral administration of aluminium chloride during 5 months caused hypoproduction of IL-6 together with a decrease in GFAP reactivity and an alteration of antioxidant status in the posterior brain. On the other hand, fenugreek seeds supplementation was able to enhance IL-6 expression, re-increase GFAP reactivity, and modulate the pro-oxidant-related effect.

DISCUSSION

In the context of recent researches, IL-6 hypoproduction in the posterior brain could be a novel mechanism of Al chronic toxicity with a direct effect on glial cells. Using FSP as a diet supplement could offer a neuroprotective effect against Al toxicity. This could be mediated by astroglial cells protection, antioxidant and immunomodulatory actions.

Rare triad of periampullary carcinoid, duodenal gastrointestinal stromal tumor and plexiform neurofibroma at hepatic hilum in neurofibromatosis type 1: a case report

Background

Neurofibromatosis type 1 is a relatively common inherited disorder. Patients with neurofibromatosis type 1 are at high risk of developing neurogenic, neuroendocrine and mesenchymal intra-abdominal tumors. Although coexistence of multiple tumors of different types is frequent in neurofibromatosis type 1, simultaneous occurrence of abdominal tumors of three types in very rare.

Case presentation

A 66-year-old lady with neurofibromatosis type 1 presented with painless progressive jaundice for six months. Laboratory investigations revealed iron deficiency anemia and conjugated hyperbilirubinemia. Tumor markers were normal. Abdominal computed tomography showed a 3 × 2 cm heterogenous mass in the periampullary region with mild dilation of the common bile duct and another 2 × 1.7 cm mass in the fourth portion of the duodenum. Endoscopic biopsy confirmed the diagnosis of periampullary carcinoid. At surgery, multiple small nodules were detected at the hepatic hilum. Frozen section suggested them to be neurofibromas. Patient underwent pancreatoduodenectomy and had uneventful recovery with no recurrence at two months. Microscopic examination of the resected specimen confirmed presence of three tumors: periampullary well differentiated neuroendocrine tumor, gastrointestinal stromal tumor of the fourth part of duodenum and plexiform neurofibroma at the hepatic hilum.

Conclusion

Patients of neurofibromatosis type 1 with abdominal symptoms should be treated with high index of clinical suspicion and thoroughly evaluated to rule out multiple tumors.

Étude du contenu en ADN nucléaire dans les nodules thyroïdiens

Thyroid nodules are frequent and sometimes they pose a diagnostic and prognostic problem. DNA ploidy study and cell cycle analysis could be of value in the distinction between benign tumors and malignant tumors. Formalin-fixed and paraffin-embedded tissues from 69 patients with different benign and neoplastic lesions were investigated. Nuclear DNA content in thyroid cells was measured after Feulgen staining using SAMBA 200 image analysis system. A diploid DNA stemline was revealed in 75% of histologically proven benign thyroid tumors (15/20) and aneuploidy was found in 57.2% of malignant tumors (28/49). There is a significant correlation between aneuploidy and extra-thyroid extension (p=0.007) and bilateral and/or mediastinal lymph node metastasis (p=0.02). In the majority of benign tumors (19/20), the proliferation index was lower than 3% (< or =3%) however, this index value was higher than 3% (>3%) in more than 83% of malignant tumors (41/49) (p<0.001). The S phase fraction analysis revealed that the threshold of 14% divide the near whole of benign and malignant tumors (p<0.001). Our findings show that in follicular lesions, proliferation index and S phase fraction study appears interesting and helpful in the distinction between benign and malignant tumors, and aneuploidy seems more interesting in prognosis evaluation of these tumors.

Trametinib Induces the Stabilization of a Dual GNAQ p.Gly48Leu- and FGFR4 p.Cys172Gly-Mutated Uveal Melanoma. The Role of Molecular Modelling in Personalized Oncology

We report a case of an uveal melanoma patient with GNAQ p.Gly48Leu who responded to MEK inhibition. At the time of the molecular analysis, the pathogenicity of the mutation was unknown. A tridimensional structural analysis showed that Gαq can adopt active and inactive conformations that lead to substantial changes, involving three important switch regions. Our molecular modelling study predicted that GNAQ p.Gly48Leu introduces new favorable interactions in its active conformation, whereas little or no impact is expected in its inactive form. This strongly suggests that GNAQ p.Gly48Leu is a possible tumor-activating driver mutation, consequently triggering the MEK pathway. In addition, we also found an FGFR4 p.Cys172Gly mutation, which was predicted by molecular modelling analysis to lead to a gain of function by impacting the Ig-like domain 2 folding, which is involved in FGF binding and increases the stability of the homodimer. Based on these analyses, the patient received the MEK inhibitor trametinib with a lasting clinical benefit. This work highlights the importance of molecular modelling for personalized oncology.

First communication on the efficacy of combined ¹⁷⁷Lutetium-PSMA with immunotherapy outside prostate cancer

Prostate-specific membrane antigen (PSMA)-targeted radioligand therapy is a validated treatment option for patients with advanced prostate cancer. Although PSMA expression is not limited to prostate tissue, little is known about its relevance to other types of cancer. Here, we present a case report of a patient with uterine leiomyosarcoma that is progressing while on immunotherapy and treated with ¹⁷⁷Lu-PSMA radionuclide therapy. We report for the first time that ¹⁷⁷Lu-PSMA radionuclide therapy combined with immunotherapy outside of prostate cancer. We did observe post-treatment reduction of tumor growth rate, although we did not notice disease response based on RECIST criteria. We suggest that ¹⁷⁷Lu-PSMA treatment especially combined with immunotherapy may be an option for patients with cancer without other therapeutic options. Insights: ¹⁷⁷Lu-PSMA radionuclide therapy should be considered for any tumor stained positive for PSMA.