Prognostic value of histopathologic traits independent of stromal tumor-infiltrating lymphocyte levels in chemotherapy-naïve patients with triple-negative breast cancer

BACKGROUND

In the absence of prognostic biomarkers, most patients with early-stage triple-negative breast cancer (eTNBC) are treated with combination chemotherapy. The identification of biomarkers to select patients for whom treatment de-escalation or escalation could be considered remains an unmet need. We evaluated the prognostic value of histopathologic traits in a unique cohort of young, (neo)adjuvant chemotherapy-naïve patients with early-stage (stage I or II), node-negative TNBC and long-term follow-up, in relation to stromal tumor-infiltrating lymphocytes (sTILs) for which the prognostic value was recently reported.

MATERIALS AND METHODS

We studied all 485 patients with node-negative eTNBC from the population-based PARADIGM cohort which selected women aged <40 years diagnosed between 1989 and 2000. None of the patients had received (neo)adjuvant chemotherapy according to standard practice at the time. Associations between histopathologic traits and breast cancer-specific survival (BCSS) were analyzed with Cox proportional hazard models.

RESULTS

With a median follow-up of 20.0 years, an independent prognostic value for BCSS was observed for lymphovascular invasion (LVI) [adjusted (adj.) hazard ratio (HR) 2.35, 95% confidence interval (CI) 1.49-3.69], fibrotic focus (adj. HR 1.61, 95% CI 1.09-2.37) and sTILs (per 10% increment adj. HR 0.75, 95% CI 0.69-0.82). In the sTILs <30% subgroup, the presence of LVI resulted in a higher cumulative incidence of breast cancer death (at 20 years, 58%; 95% CI 41% to 72%) compared with when LVI was absent (at 20 years, 32%; 95% CI 26% to 39%). In the ≥75% sTILs subgroup, the presence of LVI might be associated with poor survival (HR 11.45, 95% CI 0.71-182.36, two deaths). We confirm the lack of prognostic value of androgen receptor expression and human epidermal growth factor receptor 2 -low status.

CONCLUSIONS

sTILs, LVI and fibrotic focus provide independent prognostic information in young women with node-negative eTNBC. Our results are of importance for the selection of patients for de-escalation and escalation trials.

Photoswitching/back-switching assessment of biobased cellulose acetate/azobenzene handleable films under visible-light LED irradiation

The light-induced processes performed by photofunctional polymer films are crucial aspects of developing integrated energy storage devices properly. Herein, we report the preparation, characterization, and study of the optical properties of a series of biobased cellulose acetate/azobenzene (CA/Az1) handleable films at different compositions. The photoswitching/back-switching behavior of the samples was investigated using varied LED irradiation sources. Additionally, poly(ethylene glycol) (PEG) was deposited onto cellulose acetate/azobenzene films to study the back-switching process's effect and nature in the fabricated films. Interestingly, the melting enthalpies of PEG before and after being irradiated with blue LED light were 2.5 mJ and 0.8 mJ, respectively. Conveniently, FTIR and UV-visible spectroscopy, thermogravimetry (TGA), contact angle, differential scanning calorimetry (DSC), polarized light microscopy (PLM), and atomic force microscopy (AFM) were used for the characterization of the sample films. Complementarily, theoretical electronic calculations provided a consistent approach to the energetic change in the dihedral angles and non-covalent interaction for the trans and cis isomer in the presence of cellulose acetate monomer. The results of this study revealed that CA/Az1 films are viable photoactive materials displaying handleability attributes with potential uses in harvesting, converting, and storing light energy.

Subconjunctival Sirolimus-Loaded Liposomes for the Treatment of Moderate-to-Severe Dry Eye Disease

Purpose

To determine the effectiveness of subconjunctival application of a novel sirolimus liposomal formulation for the treatment of dry eye.

Methods

A randomized, triple-blind, Phase II clinical trial. Thirty-eight eyes of 19 patients were included. Nine patients (18 eyes) assigned to the sham group (Sham) and 10 patients (20 eyes) to sirolimus-loaded liposomes group (Sirolimus). The treatment group received three doses of subconjunctival liposome-encapsulated sirolimus and the sham group received three doses of liposomal suspension without sirolimus. Subjective (Ocular Surface Disease Index, OSDI) and measured (corrected distance visual acuity, conjunctival hyperemia, tear osmolarity, Schirmer's test, corneal/conjunctival staining and matrix metalloproteinase-9) variables were measured.

Results

Sirolimus-entrapped liposomes-treated group OSDI scores changed from 62.19 (± 6.07) to 37.8 (± 17.81) (p=0.0024), and conjunctival hyperemia from 2.0 (± 0.68) to 0.83 (± 0.61) (p<0.0001); Sham group with OSDI scores from 60.02 (± 14.2) to 36.02 (± 20.70) (p=0.01), and conjunctival hyperemia from 1.33 (± 0.68) to 0.94 (± 0.87) (p=0.048). All the other evaluated outcomes only showed significant differences in the sirolimus group: corneal/conjunctival staining score (p=0.0015), lipid layer interferometry (p=0.006), and inferior meibomian gland dropout (p=0.038). No local or systemic adverse effects regarding the medication itself were reported, and the administration route was well accepted.

Conclusion

Our findings suggest that sub-conjunctival sirolimus-loaded liposomes are effective in reducing both signs and symptoms of dry eye in patients with poorly controlled moderate-to-severe DED, while avoiding other topical administration adverse effects. Further investigation with a larger sample size is required to determine long-term effects.

OSNA Total Tumor Load for the Prediction of Axillary Involvement in Breast Cancer Patients: Should We use Different Thresholds According to the Intrinsic Molecular Subtype? MOTTO Study

Aims

To assess the impact of the molecular subtype (MS) on the total number of CK19 mRNA copies in all positive SLN (TTL) threshold, to predict non-SLN affectation, and to compare 5 years progression-free survival (PFS) according to the risk of recurrence (ROR) group by PAM50.

Methods

Cohort with infiltrating breast cancer with intra-operative metastatic SLN detected by one-step nucleic acid amplification (OSNA) assay who underwent subsequent ALND. Logistic regression was used to assess a possible interaction between TTL and MS(Triple Negative, Her-2-Enriched, Luminal A, or Luminal B), or hormone receptors (HR: positive or negative) by immunohistochemistry (IMH). Cox regression was used to compare PFS and OS in the 3 ROR groups (high, medium, or low).

Results

TTL was predictive of non-SLN affectation in both univariate (OR [95% CI]: 1.72 [1.43, 2.05], P < .001) and multivariate (1.55 [95% CI: 1.04, 2.32], P = .030) models, but MS-IMH or HR-IMH, and their interactions with TTL were not (best multivariate model: HR + main effect OR 1.16 [95% CI: 0.18, 7.64], P = .874; interaction OR: 1.04 [0.7, 1.55], P = .835; univariate model: HR + main effect OR: 1.44 [95% CI: 0.85, 2.44], P = .180). PFS was lower in the high-risk ROR group (81.1%) than in the low-risk group (93.9%) (HR: 3.68 [95 CI: 1.70, 7.94], P < .001).

Conclusions

our results do not provide evidence to support the utilization of subtype-specific thresholds for TTL values to make therapeutic decisions on the axilla. The ROR group was predictive of 5 years-PFS.

Unusual Corneal Sarcoidosis Manifestations

AIM

To document atypical presenting forms of ocular sarcoidosis at the corneal level.

METHODS

Case report.

RESULTS

A 63-year-old woman presented multiple uncommon unilateral primary corneal conditions as manifestation of ocular sarcoidosis, including peripheral ulcerative keratitis, sterile corneal infiltrate (corneal granuloma), and sterile infiltrates related to a corneal foreign body, requiring medical and surgical management to control the inflammatory symptoms and to preserve the integrity of the eyeball. An excisional biopsy of a nodule in the temporal conjunctiva was performed under topical anesthesia. Histological analysis revealed a non-caseating granuloma, confirming the diagnosis of ocular sarcoidosis.

CONCLUSION

When thinking of ocular involvement in patients with ocular sarcoidosis, it is essential to remember that manifestations such as peripheral ulcerative keratitis, sterile corneal infiltrate, and sterile foreign body-related infiltrates may be presentations of this disease.

Giant Ocular Lipodermoid Cyst in Encephalocraniocutaneous Lipomatosis: Surgical Treatment and Genetic Analysis

BACKGROUND Encephalocraniocutaneous lipomatosis is a rare neurocutaneous disorder characterized by cutaneous, ocular, and central nervous system anomalies; its molecular etiology was recently identified. This report describes the surgical treatment and genetic characterization of a giant ocular lipodermoid cyst secondary to encephalocraniocutaneous lipomatosis. CASE REPORT An 11-year-old girl with past medical history of absence seizures presented with a reddish protruding mass in her right eye involving the temporal conjunctiva and the peripheral temporal cornea; eyelid closure was not possible due to mass protrusion. She also presented skin tags at the level of the external canthus and 3 alopecic areas at the level of the scalp compatible with nevus psiloliparus. No family history was reported. A dermoid cyst was suspected and excisional biopsy was performed under general anesthesia. A large conjunctival and lamellar corneoscleral resection was done, followed by a corneal tectonic graft. Molecular analysis was carried out, including PCR and Sanger sequencing on DNA obtained from the mass. After surgery, the patient achieved complete eyelid closure, reduction of ocular surface symptoms, and improved aesthetic appearance. Histological analysis confirmed a lipodermoid cyst; genetic tests confirmed a mosaic activating mutation in FGFR1 (c.1638C>A, p.Asn546Lys). The diagnosis was encephalocraniocutaneous lipomatosis. CONCLUSIONS ECCL is a rare condition; an accurate diagnosis comprising clinical and genetic aspects can facilitate the monitoring of possible complications, improve the multidisciplinary treatment, and provide valuable information for future therapy developments. In this case, the patient's quality of life improved significantly, ocular symptoms disappeared, and a good esthetic appearance was achieved.

Effects of periodic perturbations on the oscillatory behavior in the NO+H2 reaction on Pt(100)

The mean field model proposed by Makeev and Nieuwenhuys [J. Chem. Phys. 108, 3740 (1998)] simulates the oscillatory behavior experimentally observed in the NO+H2 reaction on the surface Pt(100). This model reproduces quite well the kinetic oscillations and the transition to chaos via the Feigenbaum route, that is to say, through bifurcations involving period doubling. From this model, we analyze the response of the natural oscillations of period-1 (P1, one maximum) to periodic perturbations superposed to the partial pressure of one of the reactants. The perturbed model reproduces the periodic states found in the autonomous model, the route to chaos through bifurcations with period doubling, and the appearance of chaos via the route of intermittency, which shows alternation of periodic oscillations with intervals of disordered oscillations in the same time evolution. Experimentally it has been observed that the reaction shows a great sensitivity to reactant partial pressures and temperature. In experimental conditions slightly different to those considered in Makeev and Nieuwenhuys (MN) model, oscillations with period-3 (P3, three maxima) have been observed. At T=457 K and certain pressures, these P3 oscillations do not appear in MN model, although they appear at T=456 K . The same effect (P3 oscillations) is obtained at T=457 K in our perturbed model, due to the modulation of pH2. In a second step we show how the modulation of the perturbing frequency influences on the oscillations P1 of the perturbed system. The results show that the periodic behavior loses its regularity at low values of the normalized amplitude and of the modulated frequency of the perturbation. Other aspect observed in the perturbed model is that the amount of products varies in relation to nonperturbed model. When the oscillations are periodic or they follow the Feigenbaum route to chaos, the production average decreases or slightly increases, whereas it always increases if there are intermittencies, the most significant percentage increase being for NH3 (nearly 10%).

[Acral keratoses and inverted follicular keratosis presenting Cowden disease]

Cowden disease is a rare genetic disorder characterized by the presence of multiple hamartomas in the skin, thyroid, breast, nervous system and gastrointestinal tract. Mucocutaneous lesions are the most constant and characteristic finding. Breast and thyroid neoplasms (benign and malignant) develop in up to two thirds of patients. Inverted follicular keratosis as the presenting feature of Cowden disease is rare as the disease is usually suspected by the appearance of multiple facial trichilemmomas, oral mucosal papillomatosis and acral keratoses.

Modulación en la expresión de biomarcadores (RE, RP y C-erbB2) en cáncer de mama tras tratamiento neoadyuvante

INTRODUCTION

Pre and post-operative oncological therapy in patients with breast cancer is determined, amongst other factors, by hormone receptor status and by c-erbB2 expression. The aim of this study is to determine the influence of neoadjuvant therapy on the expression of oestrogen receptor (OR), progesterone receptor (PR) and c-erbB2.

METHODS

Fifty-three patients with breast cancer diagnosed by tru-cut biopsy were studied. Patients with locally advanced carcinoma (20) had preoperative treatment. All patients underwent surgical resection. Expression of OR, PR and c-erbB2 in both the tru-cut biopsy and the gross specimen was compared.

RESULTS

We found significant differences in OR, PR expression in both biopsy and gross specimen, between the group of patients who underwent neoadjuvant treatment and the group without pre-surgical treatment. Changes in PR, OR and c-erbB2 status were found between the tru-cut biopsy and the gross specimen, in about 10 to 40% of the cases who received neoadjuvant therapy. These changes had no statistical significance.

Stabilization from chaotic to periodical states in a model of cellular automaton for oxidation of CO

The chaotic behavior of a chemical reaction can be controlled perturbing periodically some of the parameters externally governing the reaction. Based on the resonance phenomenon, the method of external forcing can convert chaotic behavior into a periodical one through the application of a sinusoidal modulation. In this paper we analyze the effect of a periodical perturbation on room temperature in a model of cellular automaton that studies catalytic oxidation of CO. This model considers the reaction of carbon monoxide and oxygen adsorbed on a surface allowing the variation of the surface temperature and analyzing the time oscillations in the reaction. The results of simulations of this model show quasiperiodical and chaotic behaviors. Then the strategy of control through periodical forcing is able to remove the chaotic dynamics by means of the stabilization of periodical solutions, there being enough of a perturbing harmonic function with only one frequency to transform a chaotic state of the system into a periodical state with periodicity 1.

Periodical forcing for the control of chaos in a chemical reaction

Control of the chaotic behavior of a chemical system can be achieved perturbing periodically some control parameters of the system. This procedure based on external forcing, which is based on the phenomenon of resonance, can change a chaotic behavior into a periodical one by means of the application of a sinusoidal perturbation. In this paper, the influence of a periodical modulation added to the parameter controlling the oxygen adsorption rate in a cellular automaton (CA) model studying CO oxidation is analyzed. This CA model considers the oxidation reaction of CO on a catalytic surface, taking into account the catalyst temperature variation in order to analyze the reaction time oscillatory behavior. Simulations of the CA model exhibit chaotic and quasiperiodical behaviors, and it can be shown that the periodical forcing strategy can suppress the chaotic dynamics by means of the stabilization of periodical solutions.

[Sentinel node in breast cancer. Histological study of 67 cases]

BACKGROUND

The extirpation of the sentinel node is a widespread surgical technique whose aim is to avoid axillary resection in patients with breast cancer at early stages. Determination of tumoral infiltration can be evident in the case of macrometastasis (>2mm), or difficult to detect in micrometastasis (<2mm). For this reason we use a protocol of serialized sections, to increase our capacity for detecting micrometastasis. Realisation of this protocol is highly laborious and represents a high cost, thus its effectiveness and efficacy must be studied.

MATERIAL AND METHODS

We reviewed 67 sentinel nodes corresponding to 48 patients with breast cancer treated at our hospital in the last three years. All the samples received at the Pathology Unit were included. Serialized sections of three microns were made on each node and with a depth of 40 microns between them. A total of fourteen cuts were made. Every five cuts there was an alternation of immunostaining with a cocktail of queratines (AE1/AE3) and with haemotoxylin-eosin.

RESULTS

Sixty-seven sentinel nodes were extirpated from 48 patients. Fourteen positive (20%) were detected. Of these metastases, 6 were macrometastases >2mm, 5 were micrometastases <2mm and 3 were isolated cellular groups (between 0.2 and 2mm). In 6 cases (43%), the metastases only became evident with queratine staining in serialized cuts. Axillary resection was carried out in 44 cases.

CONCLUSIONS

The histological study of the sentinel nodes makes it possible to evaluate the status of tumoral infiltration of the axillary ganglions and to greatly reduce axillary lymphadenectomies. The conventional study of the sentinel node (with a single section) is insufficient for the diagnosis of tumoral infiltration. In our series, histological study using a protocol of serialized sections has enabled us to detect some 43% of metastases in the sentinel node that were not evident in the initial section.

[Comparative results of ganglion dissection in cancer of the rectum with and without prior treatment of the adipose tissue]

BACKGROUND

The aim of this study is to describe the result obtained through two techniques of isolation of lymphatic lymph nodes in surgical pieces of anterior resection due to adenocarcinoma of the rectum.

MATERIAL AND METHODS

We carried out a search in a series of 30 consecutive cases of patients operated on for adenocarcinoma of the rectum for lymph nodes first in a manual conventional way and second after 24 hours in a degreasing solution at room temperature.

RESULTS

In the first search 335 lymph nodes were lymph nodes isolated, with an average that oscillated between 6.46 and 17.58, with the lower values corresponding to the groups that had received prior adjuvant treatment. In the second inclusion, following the action of the clearing solution, we found new lymph nodes (85) in some 75% of the cases, appreciably lower in number and smaller in size than the initial search.

CONCLUSIONS

Manual lymph nodes dissection of the adipose tissue is a reliable method for the isolation of lymphatic lymph nodes in pieces of resection due to adenocarcinoma of the rectum. The search for lymphatic ganglions following the action of a clearing solution should be reserved for cases in which the minimum recommended in the TNM staging is not reached

Screening of the municipal water system of La Plata, Argentina, for human intestinal parasites

The La Plata River, though severely contaminated by intestinal parasites through the discharge of tons of crude fecal material from a main sewage channel, nevertheless provides drinking water to two-thirds of La Plata, Argentina, after conventional purification at a processing plant. With intestinal parasitosis being endemic here, we investigated the importance of this water in transmitting such pathogens to the city's populace by means of standard methodology for sample acquisition and processing involving filter-concentration of waterborne particulates. Of 14 tap-water samples collected from the distribution network, 12 pertained to four zones (A-D) within the city center; while the remaining 2 were obtained near the processing plant, 15 kilometers outside the city. Although parasites were found within the samples derived from the four urban zones, none were detected in the specimens obtained near the plant. The four downtown areas differed from each other as to the quantity and nature of the parasites present in their water: whereas zones A and B registered similar lower levels of contaminants, C and D exhibited higher values significantly different from the former two and from each other. Given an average parasite count/l citywide of 0.38 and a probability of encountering a parasite within 11 of water of 0.32, the municipal network is seen to contribute to the transmission of intestinal parasites. A routine system of water-quality control is therefore needed throughout the city along with the establishment of infrastructures for locating and eliminating peripheral sources of contamination.

Moderate hyperhomocysteinemia is a highly prevalent defect in Spanish patients with venous thromboembolic disease

Recent studies suggest that mild hyperhomocysteinemia may be a risk factor for venous thromboembolic disease (VTED). In this work we evaluated the prevalence of moderate hyperhomocysteinemia in patients with VTED in our area. We found hyperhomocysteinemia in 23.4% of 64 patients studied compared with 7.35% of 68 healthy controls (p = 0.014). Our results suggest that moderate hyperhomocysteinemia is one of the most prevalent abnormalities associated with VTED.

Granular-cell tumor of the esophagus: report of a case with a cytologic diagnosis based on esophageal brushing

We report a case of granular-cell tumor (GCT) in the esophagus. This is a rare location for this tumor and only 80 cases have been described. The tumor was diagnosed in a 24-yr-old woman with epigastralgia. Endoscopic examination revealed a submucosal ulcerated lesion. The smears derived from esophageal brushings contained clusters of granular cells. Histologic examination of the endoscopic biopsy provided diagnostic confirmation of GCT. To our knowledge, this is the first reported case of esophageal GCT in which the characteristic tumor cells were seen in the endoscopic brushing material. This case demonstrates that a cytologic diagnosis of GCT is possible if the lesion is ulcerated and/or brushing is subsequent to taking the biopsy. Although rare in the esophagus, GCT should be considered in the differential diagnosis of esophageal neoplasms.

[Factors affecting the in vitro excystation of Cryptosporidium sp]

To assess the viability of the oocysts from Cryptosporidium sp, an in vitro excystation technique was developed and optimized. To this end, oocysts from Cryptosporidium sp were isolated from a sample of fecal material from a child with symptomatic cryptosporidiosis. The specimen was processed by a discontinuous-sucrose-gradient technique yielding a final suspension of purified and concentrated oocysts. The resulting oocysts were quantified by counting an aliquot in a Neubauer hemocytometer chamber and the remainder were preserved in phosphate-buffered saline at pH 7.2 and 4 degrees C. The two protocols tested through the use of 100-microliter aliquots containing 178,000 oocytes/mm3 were: I. Treatment at 37 degrees C for 24 h with 1% (v/v) bile plus 0.44% (w/v) sodium bicarbonate. Group A: pretreated with acidified trypsin (pH 2.75) at 37 degrees C for 1 h; Group B: not pretreated. II. Treatment at 37 degrees C for 24 h with 1% (v/v) bile at pH 6 and at pH 8 either with or without 0.44% (w/v) sodium bicarbonate in air or an atmosphere containing 10% (v/v) CO2. Group 1: bile, pH 6; Group 2: bile, pH 6 plus CO2; Group 3: bile, pH 6 plus bicarbonate; Group 4: bile, pH 8 plus bicarbonate; Group 5: bile, pH 6 plus bicarbonate plus CO2; Group 6: bile, pH 8 plus bicarbonate plus CO2; Group 7: bile, pH 8; and Group 8: bile, pH 8 plus CO2. We then assessed the degree of excystation in all the groups by counting the number of intact oocysts in the hemocytometer. For the first protocol, the oocyst count after excystation revealed an average of 28,000 oocysts/mm3 in Group A and 22,000 in Group B. These values indicate excystation frequencies of 84.3% and 87.6% for these two groups, respectively. The corresponding excystation percentages for groups 1-8 of protocol II were 49.5, 56.7, 83.2, 88.3, 88.3, 92.7, and 94.1, respectively. Preincubation with trypsin failed to augment oocyst excystation in Cryptosporidium in any of these experimental circumstances. The optimal conditions for oocyst excystation in these 24 h incubations were thus seen to be in the presence of 1% (v/v) bile at pH 8, and 37 degrees C under an atmosphere of 10% (v/v) CO2.

Plasma homocysteine is related to albumin excretion rate in patients with diabetes mellitus: a new link between diabetic nephropathy and cardiovascular disease?

The high risk of cardiovascular disease in patients with diabetes mellitus, particularly in those with nephropathy, is not completely explained by classical risk factors. A high plasma homocysteine concentration is an independent risk factor for cardiovascular disease but information on its association with diabetes is limited. Fasting homocysteine concentrations were measured in the plasma of 165 diabetic patients (75 with insulin-dependent [IDDM]; 90 with non-insulin-dependent diabetes [NIDDM]) and 56 non-diabetic control subjects. Other measurements included the prevalence of diabetic complications, glycaemic control, lipid and lipoprotein levels, vitamin status and renal function tests. Patients with NIDDM had higher homocysteine levels than control subjects, whereas IDDM patients did not (9.2 +/- 4.5 vs 7.7 +/- 2 micromol/l, p < 0.01; and 7.0 +/- 3 vs 7.4 +/- 2 micromol/l, NS). Univariate correlations and multiple regression analysis showed albumin excretion rate to be the parameter with the strongest independent association with homocysteine. Patients with both types of diabetes and nephropathy had higher plasma homocysteine concentrations than those without nephropathy. Increases of homocysteine in plasma were related to increases in the severity of the nephropathy. Fasting hyperhomocysteinaemia was considered as the mean of the plasma homocysteine for all control subjects (7.5 +/- 2.1 micromol/l) + 2 SD (cut-off = 11.7 micromol/l). Nephropathy was present in 80 % of diabetic patients with fasting hyperhomocysteinaemia. In conclusion, increases in fasting homocysteine in diabetic patients are associated with increased albumin excretion rate, especially in those with NIDDM, thus providing a potential new link between microalbuminuria, diabetic nephropathy and cardiovascular disease.

[Dendriform diffuse pulmonary ossification. Report of 2 cases]

Two cases of diffuse dendriform pulmonary ossification are reported which was diagnosed postmorten. Both patients had a previous history of chronic obstructive pulmonary disease with pneumonic complications. The radiological study was interpreted as pulmonary fibrosis in the first case, an entity which ranks first in the differential diagnosis. In some cases the obtention of highly contrasted X-ray films can be useful for recognizing this are entity.

[Verrucous carcinoma of the penis: report of two cases]

OBJECTIVES

Verrucous carcinoma, a variant of squamous cell carcinoma accounts for 5%-8% of all penile tumors. The unique histological features and behaviour of this tumor type prompted us to report these two cases.

A trigonometric sum relevant to the nonrelativistic theory of atoms

We extend Van der Corput's method for exponential sums to study an oscillatory term appearing in the quantum theory of large atoms. We obtain an interpretation in terms of classical dynamics and we produce sharp asymptotic upper and lower bounds for the oscillations.