Comparison of Intraoperative Sonography and Histopathologic Evaluation of Tumor Thickness and Depth of Invasion in Oral Tongue Cancer: A Pilot Study

BACKGROUND AND PURPOSE

For primary squamous cell carcinoma of the oral tongue, accurate assessment of tumor thickness and depth of invasion is critical for staging and operative management. Currently, typical imaging modalities used for preoperative staging are CT and MR imaging. Intraoperatively, CT or MR imaging cannot provide real-time guidance, and assessment by manual palpation is limited in precision. We investigated whether intraoperative sonography is a feasible technique for assessment of tumor thickness and depth of invasion and validated its accuracy by comparing it with histopathologic evaluation of the resected specimen.

MATERIALS AND METHODS

Twenty-six patients with squamous cell carcinoma of the oral tongue who underwent tumor resection by a single surgeon between March 31, 2016, and April 26, 2019, were prospectively identified. Intraoperative sonography was obtained in planes longitudinal and transverse to the long axis of the tumor. Twenty-two patients had archived images that allowed measurements of tumor thickness and depth of invasion sonographically. Two patients had dysplasia and were excluded. The remaining 20 patients had histologic tumor thickness and histologic depth of invasion measured by a single pathologist.

RESULTS

The mean sonographic tumor thickness was 7.5  ± 3.5 mm, and the mean histologic tumor thickness was 7.0  ± 4.2 mm. Mean sonographic depth of invasion and histologic depth of invasion were 6.6  ± 3.4  and 6.4 ± 4.4 mm, respectively. There was excellent correlation between sonographic and histologic measurements for both tumor thickness and depth of invasion with Pearson correlation coefficients of 0.95 (95% CI, 0.87-0.98) and 0.95 (95% CI, 0.87-0.98), respectively.

CONCLUSIONS

Intraoperative sonography can provide reliable, real-time assessment of the extent of tongue tumors.

Cleft of the secondary palate without cleft lip diagnosed with three-dimensional ultrasound and magnetic resonance imaging in a fetus with Fryns' syndrome

We present a case of Fryns' syndrome diagnosed prenatally using three-dimensional (3D) ultrasonography and magnetic resonance imaging (MRI). A cleft of the soft palate was diagnosed using 3D thick-slice ultrasonography. Other sonographic findings included a right diaphragmatic hernia, enlarged echogenic kidneys and severe polyhydramnios. The detection of the cleft palate was instrumental in suggesting the diagnosis of Fryns' syndrome in a fetus which also had a diaphragmatic hernia. These findings were also demonstrated with prenatal MRI. The technique of imaging the soft palate en face using a thick-slice technique is presented.

Congenital hypothyroidism in a child with unsuspected familial dysalbuminemic hyperthyroxinemia caused by a mutation (R218H) in the human albumin gene

We found familial dysalbuminemic hyperthyroxinemia (FDH) in a 5-month-old boy with congenital hypothyroidism (CH) who had a blood thyrotropin (TSH) level of 479 mU/L but normal total serum thyroxine (T4) and higher than normal total triiodothyronine (T3) levels. Thyroid hormone substitution began at 5 weeks of age when T4 and T3 concentrations were below normal. Until the age of 5 months, treatment with levothyroxine was suboptimal on the basis of high serum TSH levels despite above-normal T4 levels. FDH was confirmed by isoelectric focusing and testing of other family members. DNA analysis of the patient revealed R218H, a mutation in the serum albumin gene associated with FDH, which was also present in the patient's euthyroid father and brother. Thyroid scans, serum thyroglobulin measurements, and free T4 measurements using equilibrium dialysis or 2-step immunoassay methods can identify thyroid hormone-binding protein defects and simplify the diagnosis and treatment of infants with CH.

Search for abnormalities of nuclear corepressors, coactivators, and a coregulator in families with resistance to thyroid hormone without mutations in thyroid hormone receptor beta or alpha genes

The syndrome of resistance to thyroid hormone (RTH) is characterized by decreased tissue responsiveness to thyroid hormones. Inheritance is usually autosomal dominant due to mutations in the ligand-binding domain or adjacent hinge region of the thyroid hormone receptor beta (TRbeta) gene. Six of 65 families with the RTH phenotype studied in our laboratory had normal TRbeta1 and TRbeta2 gene sequences. Their clinical characteristics were not different from those of subjects with TRbeta gene mutations. Four of the 6 families were amenable to linkage analysis, and TRalpha involvement was excluded. Candidate genes were then evaluated for their possible involvement in the RTH phenotype in these 4 families: 2 coactivators [NCoA-1 (SRC-1) and NCoA-3 (AIB-1)], 2 corepressors (NCoR and SMRT), and a coregulator (RXRgamma). DNA was obtained from 8 affected subjects and 41 of 45 living first degree relatives. In 2 of the 4 families, the mode of inheritance could be determined by pedigree analysis and was found to be autosomal dominant. Linkage analyses were performed using polymorphic markers near or within the 5 candidate genes. When analyses were not informative or linkage could not be excluded, direct sequencing of the genes in question was performed. Involvement of NCoA-1 was excluded in all four families assuming autosomal dominant inheritance. Roles for NCoR, SMRT, and NCoA-3 were excluded in three and a role for RXRgamma was excluded in two of the four families. However, if the two families without proven dominant mode of inheritance were compound heterozygous, only the involvement of NCoA-1 could be excluded in both. Roles for NCoR, SMRT, and RXRgamma were excluded in one of these two families. Thus, NCoA-1 and RXRgamma genes were not found to be the cause of RTH in subjects without TR gene mutations even though the absence of NCoA-1 and RXRgamma is the cause of RTH in mice. Involvement of other candidate genes in the mediation of thyroid hormone action as well as intracellular hormone transport needs to be explored in these families with non-TRbeta, TRalpha RTH.

A novel point mutation in cluster 3 of the thyroid hormone receptor beta gene (P247L) causing mild resistance to thyroid hormone

Resistance to thyroid hormone (RTH), a syndrome characterized by variable tissue hyposensitivity to thyroid hormone (TH), is linked to mutations in the thyroid hormone receptor (TR) beta gene. We report a new family with a heretofore unreported mutation, P247L. The proposita, a 31-year-old female, presented with goiter and palpitations. RTH was suspected because of elevated serum free thyroxine (FT4) level with a normal thyrotropin (TSH). Sequencing the TRbeta gene revealed a mutation causing replacement of a proline at position 247 with leucine. Seven family members were heterozygous for the mutation, two of whom also had evidence of autoimmune thyroid disease. The mutant TRbeta had a Ka for triiodothyronine (T3) 30% that of the wild-type TRbeta, approximately a threefold reduction in T3-induced transactivation and a low level dominant negative activity when tested with a positively regulated reporter gene. In vivo sensitivity to TH was evaluated in three affected subjects by measurement of the responses to graded doses of levotriiodothyronine (LT3). Peak TSH responses to TRH were reduced and were not completely suppressed at even the highest dose of LT3, (0.9, 0.2, and 0.2, compared to < 0.01 microU/mL in unaffected controls), confirming pituitary resistance to TH in all three subjects. In contrast, peripheral tissues responded variably to LT3: serum cholesterol decreased in all by 15%-25%, serum creatine kinase decreased by 15% in two subjects and increased 35% in another, but serum ferritin and sex hormone-binding globulin increased in only one of the three affected individuals that were tested. Basal metabolic rate and sleeping pulse did not change in three and two individuals, respectively. Hyporesponsiveness to exogenous TH established the clinical diagnosis of RTH in one member of the family with a mutant TRbeta but normal tests of thyroid function at baseline. Three affected subjects had an axis I diagnosis of major depression but had Wechsler Intelligence Scale for Children, III (WISC-III) full-scale IQs (FSIQs) in the normal range. This novel TRbeta mutation is associated with a realtively mild RTH. Results of responses to LT3 underscore the variable phenotype of RTH.

Differential inhibition of collagenase and interleukin-1alpha gene expression in cultured corneal fibroblasts by TGF-beta, dexamethasone, and retinoic acid

PURPOSE

Expression of the genes for collagenase and interleukin-1alpha (IL-1alpha) are induced as stromal cells become activated to the repair fibroblast phenotype after injury to the cornea. This investigation examines the mechanisms whereby expression of these genes is inhibited by transforming growth factor-beta (TGF-beta), dexamethasone (DEX), or retinoic acid (RET A).

METHODS

A model of freshly isolated cultures of corneal stromal cells and early passage cultures of corneal fibroblasts was used in these studies. This model reproduces the events of stromal cell activation in the corneal wound.

RESULTS

In early passage cultures of corneal fibroblasts, expression of collagenase is under obligatory control by autocrine IL-1alpha. IL-1alpha controls its own expression through an autocrine feedback loop that is dependent on transcription factor NF-kappaB. TGF-beta, DEX, and RET A were each effective inhibitors of collagenase gene expression in these cells. Furthermore, these agents have the capacity to inhibit expression of IL-1alpha and this was correlated with their ability to affect DNA-binding activity of NF-kappaB. However, TGF-beta, DEX, and RET A were also effective inhibitors of the low level of collagenase expressed by freshly isolated corneal stromal cells that cannot express IL-1alpha.

CONCLUSIONS

In cells with an active IL-1alpha autocrine loop there are at least two distinct signaling pathways by which collagenase gene expression can be modulated. The results of this study demonstrate that TGF-beta, DEX, and RET A differentially inhibit collagenase and IL-1alpha gene expression. This information will be useful in the design of therapeutic modalities for fibrotic disease in the cornea and other parts of the eye.

Repair phenotype in corneal fibroblasts is controlled by an interleukin-1 alpha autocrine feedback loop

PURPOSE

To explore the role of autocrine interleukin-1 alpha (IL-1 alpha) as a central regulator of the repair phenotype in corneal fibroblasts.

METHODS

Disruption of the actin cytoskeleton with cytochalasin B (CB), which mimics changes in shape that occur in repair tissues, was used to stimulate repair gene expression in early-passage fibroblasts. Changes in expression of IL-1 alpha, IL-8, collagenase, and ENA-78 were determined by Northern blot analysis, radioimmunoassay, and an enzyme-amplified sensitivity immunoassay (EASIA). Expression of repair genes was also examined in repair fibroblasts, isolated from healing, penetrating keratectomy wounds in rabbits.

RESULTS

Blocking IL-1 alpha activity prevented both constitutive and stimulated increases in synthesis of IL-8 and collagenase in early-passage cultures of corneal fibroblasts, demonstrating the role of IL-1 alpha as a necessary intermediate for expression of these genes. Evidence is also presented that the IL-1 alpha autocrine controls expression of an IL-8 related factor, ENA-78. Unlike early-passage fibroblasts, fibroblasts freshly isolated from the uninjured cornea did not express IL-1 alpha. However, fibroblasts freshly isolated from remodeling corneal repair tissue 3 weeks after injury were found to express substantial levels of IL-1 alpha, regulated through an autocrine feedback loop. Neutralization experiments demonstrated that the IL-1 alpha autocrine is largely responsible for controlling both collagenase and IL-8 synthesis in repair fibroblasts, as it is in early-passage fibroblasts.

CONCLUSIONS

These findings provide evidence that activation of an autocrine IL-1 alpha feedback loop is an important mechanism by which fibroblasts adopt a repair phenotype during remodeling of the cornea.

Role of matrix metalloproteinases in failure to re-epithelialize after corneal injury

Delayed re-epithelialization of the cornea after injury usually precedes stromal ulceration. Previous findings using a rat thermal injury model suggested that re-epithelialization is impeded by products of resident corneal cells, which destroy adhesive structures at the basement membrane zone. In this study, we provide additional evidence for this concept. Failure to re-epithelialize was found to correlate with an increase in the amounts of gelatinolytic matrix metalloproteinases present in the rat cornea. One of these gelatinases, gelatinase B, is synthesized by the resident corneal cells, and inhibitions of its synthesis correlated with inhibition of basement membrane dissolution. The matrix metalloproteinases collagenase and stromelysin are also synthesized by resident corneal cells in thermally injured corneas of rabbits, but the timing of bulk enzyme synthesis correlated more closely with deposition of repair tissue in the stroma than with failure to re-epithelialize. Nevertheless, in human corneas with repair defects, gelatinase B and collagenase are synthesized by cells in the basal layer of the epithelium directly adjacent to the basement membrane, suggesting that both could participate in dissolution of this structure. Importantly, treatment of thermally injured corneas with a synthetic inhibitor of matrix metalloproteinases significantly improved basement membrane integrity. These data support the concept that over-expression of matrix metalloproteinases by resident corneal cells impedes re-epithelialization after some types of corneal injury.

Competence for collagenase gene expression by tissue fibroblasts requires activation of an interleukin 1 alpha autocrine loop

The enzyme collagenase (EC 3.4.24.7), a key mediator in biological remodeling, can be induced in early-passage fibroblasts by a wide variety of agents and conditions. In contrast, at least some primary tissue fibroblasts are incompetent to synthesize collagenase in response to many of these stimulators. In this study, we investigate mechanisms controlling response to two of the conditions in question: (i) trypsin or cytochalasin B, which disrupt actin stress fibers, or (ii) phorbol 12-myristate 13-acetate (PMA), which activates growth factor signaling pathways. We demonstrate that collagenase expression stimulated by trypsin or cytochalasin B is regulated entirely through an autocrine cytokine, interleukin 1 alpha (IL-1 alpha). The IL-1 alpha intermediate also constitutes the major mechanism by which PMA stimulates collagenase expression, although a second signaling pathway(s) contributes to a minor extent. Elevation of the IL-1 alpha level in response to stimulators is found to be sustained by means of an autocrine feedback loop in early-passage fibroblast cultures. In contrast, fibroblasts freshly isolated from the tissue are incompetent to activate and sustain the IL-1 alpha feedback loop, even though they synthesize collagenase in response to exogenous IL-1. We conclude that this is the reason why tissue fibroblasts are limited, in comparison with subcultured fibroblasts, in their capacity to synthesize collagenase. Activation of the IL-1 alpha feedback loop, therefore, seems likely to be an important mechanism by which resident tissue cells adopt the remodeling phenotype.