Advancing the PD-L1 CPS test in metastatic TNBC: Insights from pathologists and findings from a nationwide survey

Pembrolizumab has received approval as a first-line treatment for unresectable/metastatic triple-negative breast cancer (mTNBC) with a PD-L1 combined positive score (CPS) of ≥ 10. However, assessing CPS in mTNBC poses challenges. Firstly, it represents a novel analysis for breast pathologists. Secondly, the heterogeneity of PD-L1 expression in mTNBC further complicates the assessment. Lastly, the lack of standardized assays and staining platforms adds to the complexity. In KEYNOTE trials, PD-L1 expression was evaluated using the IHC 22C3 pharmDx kit as a companion diagnostic test. However, both the 22C3 pharmDx and VENTANA PD-L1 (SP263) assays are validated for CPS assessment. Consequently, assay-platform choice, staining conditions, and scoring methods can significantly impact the testing outcomes. This consensus paper aims to discuss the intricacies of PD-L1 CPS testing in mTNBC and provide practical recommendations for pathologists. Additionally, we present findings from a nationwide Italian survey elucidating the state-of-the-art in PD-L1 CPS testing in mTNBC.

Case Report: Adjuvant image-guided radiation therapy reduces surgical invasiveness in malignant peripheral nerve sheath tumors

Introduction

Malignant peripheral nerve sheath tumors (MPNSTs) are a group of rare soft tissue sarcomas of mesenchymal origin. These tumors generally require extensive local excision owing to their aggressive potential. Though the role of radiotherapy is controversial, in this report, we present the case of an MPNST in the forearm that was treated with microsurgery followed by image-guided radiation therapy to achieve complete tumor disappearance at the 18-month follow-up.

Case report

A 69-year-old woman with underlying paranoid schizophrenia was referred to our department with pain, severe swelling, and ecchymosis of her right forearm. Physical examination showed hypoesthesia in the segments innervated by the median nerve and reduced motor strength of her right hand. A gadolinium-enhanced MRI showed a large malignant peripheral nerve sheath tumor (13 x 8 x 7 cm) of the median nerve in the forearm. She underwent microsurgical en-bloc tumor resection with sparing of the median nerve. Thirty-five days postoperatively, she underwent image-guided radiotherapy (IGRT) using volumetric modulated arc therapy (VMAT). Serial MRI scans of the forearm with Gadolinium and whole-body CT scan with contrast enhancement at 30 days, 6 months, 1 year, and 18 months postoperatively documented no tumor recurrence, remnants, or metastases.

Conclusions

In this report, we demonstrate the successful use of advanced radiotherapy techniques such as IGRT while avoiding demolitive surgery for MPNST. Though a longer follow-up is necessary, at the 18-month follow-up, the patient demonstrated good outcomes from surgical resection followed by adjuvant RT for MPNST in the forearm.

Ageing, functioning patterns and their environmental determinants in the spinal cord injury (SCI) population: A comparative analysis across eleven European countries implementing the International Spinal Cord Injury Community Survey

BACKGROUND

As the European population with Spinal Cord Injury (SCI) is expected to become older, a better understanding of ageing with SCI using functioning, the health indicator used to model healthy ageing trajectories, is needed. We aimed to describe patterns of functioning in SCI by chronological age, age at injury and time since injury across eleven European countries using a common functioning metric, and to identify country-specific environmental determinants of functioning.

METHODS

Data from 6'635 participants of the International Spinal Cord Injury Community Survey was used. The hierarchical version of Generalized Partial Credit Model, casted in a Bayesian framework, was used to create a common functioning metric and overall scores. For each country, linear regression was used to investigate associations between functioning, chronological age, age at SCI or time since injury for persons with para- and tetraplegia. Multiple linear regression and the proportional marginal variance decomposition technique were used to identify environmental determinants.

RESULTS

In countries with representative samples older chronological age was consistently associated with a decline in functioning for paraplegia but not for tetraplegia. Age at injury and functioning level were associated, but patterns differed across countries. An association between time since injury and functioning was not observed in most countries, neither for paraplegia nor for tetraplegia. Problems with the accessibility of homes of friends and relatives, access to public places and long-distance transportation were consistently key determinants of functioning.

CONCLUSIONS

Functioning is a key health indicator and the fundament of ageing research. Enhancing methods traditionally used to develop metrics with Bayesian approach, we were able to create a common metric of functioning with cardinal properties and to estimate overall scores comparable across countries. Focusing on functioning, our study complements epidemiological evidence on SCI-specific mortality and morbidity in Europe and identify initial targets for evidence-informed policy-making.

Contralateral Interhemispheric Transfalcine Approach for Supratentorial Extraventricular Ependymoma Resection

BACKGROUND/AIM

Extraventricular supratentorial ependymomas are rare entities. Most ependymomas are located at the infratentorial and intraventricular level, and only in a small group of cases they do not present continuity with the ventricular system. This is a case report of a patient with an atypical location of a cerebral ependymoma, which required the implementation of a complex and infrequent approach for its complete microsurgical removal.

CASE REPORT

A 16-year-old male patient was referred at our department with a diagnosis of a 40 mm × 50 mm × 60 mm solid-cystic space-occupying lesion, sited between the left superior frontal-cingulate gyri. A contralateral transfalcine interhemispheric approach was selected, which achieved total resection of the tumor. The histopathological diagnosis of Grade II ependymoma was obtained according to WHO classification.

CONCLUSION

The contralateral transfalcine interhemispheric approach represents a favorable surgical corridor to achieve a total resection of the tumor lesion and is favored by an adequate working angle and reduced brain manipulation.

Extra-Neural Metastases From Primary Intracranial Ependymomas: A Systematic Review

Background

Primary intracranial ependymomas (IE) are rare brain tumors rarely metastasizing outside the central nervous system. We systematically reviewed the literature on extra-neural metastases from primary IEs.

Methods

PubMed, Scopus, Web-of-Science, and Cochrane were searched following the PRISMA guidelines to include studies of extra-neural metastases from primary IEs. Clinical features, management strategies, and survival were analyzed.

Results

We collected 48 patients from 43 studies. Median age was 13 years (range, 2-65). Primary IEs were frequently located in the parietal (22.9%) and frontal (16.7%) lobes, and mostly treated with resection (95.8%) and/or radiotherapy (62.5%). Most IEs were of grade-III (79.1%), and few of grade-I (6.3%) or grade-II (14.6%). 45 patients experienced intracranial recurrences, mostly treated with resection (86.7%), radiotherapy (60%), and/or chemotherapy (24.4%). Median time-interval from primary IEs was 28 months (range, 0-140). Most extra-neural metastases were diagnosed at imaging (37.5%) or autopsy (35.4%). Extra-neural metastases were multifocal in 38 patients (79.1%), mostly involving cervical or hilar lymph-nodes (66.7%), lung/pleura (47.9%), and/or scalp (29.1%). Surgical resection (31.3%), chemotherapy (31.3%) and locoregional radiotherapy (18.8%) were the most common treatments for extra-neural metastases, but 28 (58.3%) patients were not treated. At last follow-up, 37 patients died with median overall-survivals from primary IEs of 36 months (range, 1-239), and from extra-neural metastases of 3 months (range, 0.1-36). Overall-survival was significantly longer in patients with grade-I and II IEs (P=0.040).

Conclusion

Extra-neural metastases from primary IEs are rare, but mostly occur at later disease stages. Multidisciplinary management strategies should be intended mostly for palliation.

Spontaneous sacral fracture with associated acrometastasis of the hand

Background:

Acrometastases, secondary tumors affecting oncological patients with systemic metastases, are associated with a poor prognosis. In rare cases, acrometastases may precede establishing the primary tumor diagnosis.

Case Description:

A 72-year-old female heavy smoker presented with low back pain, and right lower extremity sciatica/radiculopathy. X-rays, CT, MR, and PET-CT scans documented primary lung cancer with multi-organ metastases and accompanying pathological fractures involving the sacrum (S1) and right 4^th digit. She underwent a S1 laminectomy and amputation of the distal phalanx of the right fourth finger. The histological examination documented a poorly differentiated pulmonary adenocarcinoma infiltrating bone and soft tissues in the respective locations. The patient was treated with a course of systemic immunotherapy (i.e. pembrolizumab). At 6-month follow-up, the patient is doing well and can stand and walk without pain.

Conclusion:

Spontaneous sacral fractures may be readily misdiagnosed as osteoporotic and/or traumatic lesions. However, in this case, the additional simultaneous presence of a lytic finger lesion raised the suspicion that these were both metastatic tumors. Such acrometastases, as in this case attributed to a lung primary, may indeed involve the spine.

Constitutive PSGL-1 Correlates with CD30 and TCR Pathways and Represents a Potential Target for Immunotherapy in Anaplastic Large T-Cell Lymphoma

Simple Summary

P-selectin glycoprotein ligand-1 (PSGL-1), coded by the SELPLG gene, is the major ligand of selectins and plays a pivotal role in tethering, rolling and extravasation of immune cells. PSGL-1 involvement in core molecular programs, such as SYK, PLCγ2, PI3Kγ or MAPK pathways, suggests additional functions beyond the modulation of cell trafficking. Recently, several studies identified a novel mechanism responsible for PSGL-1-mediated immune suppression in the tumor microenvironment and proved a novel concept of PSGL-1 as a critical checkpoint molecule for tumor immunotherapy. The immunotherapeutic approach has gained an ever-growing interest in the treatment of several hematological malignancies, and in particular, novel targets for immunotherapy are still highly sought-after in T-cell lymphomas. Based on our results obtained through gene expression profiling and immunohistochemical analysis, PSGL-1, already suggested as a potential target in multiple myeloma humoral immunotherapy, could be considered noteworthy among the candidates.

Abstract

Due to the high expression of P-selectin glycoprotein ligand-1 (PSGL-1) in lymphoproliferative disorders and in multiple myeloma, it has been considered as a potential target for humoral immunotherapy, as well as an immune checkpoint inhibitor in T-cells. By investigating the expression of SELPLG in 678 T- and B-cell samples by gene expression profiling (GEP), further supported by tissue microarray and immunohistochemical analysis, we identified anaplastic large T-cell lymphoma (ALCL) as constitutively expressing SELPLG at high levels. Moreover, GEP analysis in CD30+ ALCLs highlighted a positive correlation of SELPLG with TNFRSF8 (CD30-coding gene) and T-cell receptor (TCR)-signaling genes (LCK, LAT, SYK and JUN), suggesting that the common dysregulation of TCR expression in ALCLs may be bypassed by the involvement of PSGL-1 in T-cell activation and survival. Finally, we evaluated the effects elicited by in vitro treatment with two anti-PSGL-1 antibodies (KPL-1 and TB5) on the activation of the complement system and induction of apoptosis in human ALCL cell lines. In conclusion, our data demonstrated that PSGL-1 is specifically enriched in ALCLs, altering cell motility and viability due to its involvement in CD30 and TCR signaling, and it might be considered as a promising candidate for novel immunotherapeutic approaches in ALCLs.

Unexpected Mycoplasma hominis infection in two renal transplant recipients traced back to the same donor by whole-genome sequencing

Mycoplasma hominis is a common colonizer of the lower genitourinary tract. Although its clinical relevance for causing urogenital infections in immunocompetent individuals is controversial, this bacterium has been involved in severe invasive infections in allograft recipients. In this report, we describe two cases of M. hominis infection in two young renal transplant recipients within the first month post-transplant. Although at first no epidemiological link between the two cases had been suspected, whole-genome sequencing (WGS) analysis showed that both isolates were identical, highly suggestive of an origin with the common organ donor.

Donor Specificity but Not Broadness of Sensitization Is Associated With Antibody-Mediated Rejection and Graft Loss in Renal Allograft Recipients

Panel-reactive antibodies are widely regarded as an important immunological risk factor for rejection and graft loss. The broadness of sensitization against HLA is most appropriately measured by the "calculated population-reactive antibodies" (cPRA) value. In this study, we investigated whether cPRA represent an immunological risk in times of sensitive and accurate determination of pretransplantation donor-specific HLA antibodies (DSA). Five hundred twenty-seven consecutive transplantations were divided into four groups: cPRA 0% (n = 250), cPRA 1-50% (n = 129), cPRA 51-100% (n = 43), and DSA (n = 105). Patients without DSA were considered as normal risk and received standard immunosuppression without T cell-depleting induction. Patients with DSA received an enhanced induction therapy and maintenance immunosuppression. Surveillance biopsies were performed at 3 and 6 months. Median follow-up was 5.7 years. Among the three cPRA groups, there were no differences regarding the 1-year incidence of ABMR (p = 0.16) and TCMR (p = 0.75). The 5-year allograft survival rates were similar and around 87% (p = 0.28). The estimated glomerular filtration rate at last follow-up was 50-53 mL/min (p = 0.45). On multivariable Cox proportional hazard analysis, the strongest independent predictor for ABMR and (death-censored) graft survival was pretransplantation DSA. cPRA were not predictive for ABMR, TCMR, or (death-censored) graft survival. We conclude that with current DSA assignment, the broadness of sensitization measured by cPRA does not imply an immunological risk.

Effects of weak/non-complement-binding HLA antibodies on C1q-binding

It is unknown under what conditions and to what extent weak/non-complement (C)-binding IgG subclasses (IgG2/IgG4) can block C1q-binding triggered by C-binding IgG subclasses (IgG1/IgG3). Therefore, we investigated in vitro C1q-binding induced by IgG subclass mixtures targeting the same HLA epitope. Various mixtures of HLA class II specific monoclonal antibodies of different IgG subclasses but identical V-region were incubated with HLA DRB1*07:01 beads and monitored for C1q-binding. The lowest concentration to achieve maximum C1q-binding was measured for IgG3, followed by IgG1, while IgG2 and IgG4 did not show appreciable C1q-binding. C1q-binding occurred only after a critical amount of IgG1/3 has bound and sharply increased thereafter. When both, C-binding and weak/non-C-binding IgG subclasses were mixed, C1q-binding was diminished proportionally to the fraction of IgG2/4. A 2- to 4-fold excess of IgG2/4 inhibited C1q-binding by 50%. Very high levels (10-fold excess) almost completely abrogated C1q-binding even in the presence of significant IgG1/3 levels that would usually lead to strong C1q-binding. In sensitized renal allograft recipients, IgG subclass constellations with ≥ 2-fold excess of IgG2/4 over IgG1/3 were present in 23/66 patients (34.8%) and overall revealed slightly decreased C1q signals. However, spiking of patient sera with IgG2 targeting a different epitope than the patient's IgG1/3 synergistically increased C1q-binding. In conclusion, if targeting the same epitope, an excess of IgG2/4 is repressing the extent of IgG1/3 triggered C1q-binding in vitro. Such IgG subclass constellations are present in about a third of sensitized patients and their net effect on C1q-binding is slightly inhibitory.

Axillary intranodal palisaded myofibroblastoma: report of a case associated with chronic mastitis

Intranodal palisaded myofibroblastoma is a rare tumour of the lymph node that may be derived from myofibroblasts. The most usual area of presentation is the inguinal lymph nodes, but occurrence within other areas has also been reported. It is characterised by spindle cells, amianthoid-like fibres, and by the proliferation of hemosiderin-containing histiocytes in the lymph node. Although intranodal palisaded myofibroblastoma is benign, it is frequently confused with metastatic lesions, especially when it occurs in atypical sites. We herein report the second case of axillary intranodal palisaded myofibroblastoma occurring in a woman with a granulomatous chronic mastitis. The salient clinicopathological features of this unusual tumour are presented with emphasis to the pathogenesis of the tumour as well as to its histological and immunohistochemical characteristics. Clinicians and pathologists must be aware of this rare tumour to avoid a misdiagnosis of malignancy and assure patient a correct therapeutic management.

Detection of clinical and subclinical tubulo-interstitial inflammation by the urinary CXCL10 chemokine in a real-life setting

Urinary CXCL10 is a promising noninvasive biomarker for tubulo-interstitial allograft inflammation, but its diagnostic characteristics have not been assessed in a real-life setting. We investigated urinary CXCL10 in 213 consecutive renal allograft recipients having 362 surveillance biopsies at 3/6 months and 80 indication biopsies within the first year posttransplant. Allograft histology results were classified as (i) acute Banff score zero, (ii) interstitial infiltrates only, (iii) tubulitis t1, (iv) tubulitis t2-3 and (v) isolated vascular compartment inflammation. For clinical and subclinical pathologies, urinary CXCL10 correlated well with the extent of tubulo-interstitial inflammation. To determine diagnostic characteristics of urinary CXCL10, histological groups were separated into two categories: no relevant inflammation (i.e. acute Banff score zero and interstitial infiltrates only) versus all other pathologies (i.e. tubulitis t1-3 and isolated vascular compartment inflammation). For subclinical pathologies, AUC was 0.69 (sensitivity 61%, specificity 72%); for clinical pathologies, AUC was 0.74 (sensitivity 63%, specificity 80%). A urinary CXCL10-guided biopsy strategy would have reduced performance of surveillance and indication biopsies by 61% and 64%, respectively. Missed (sub)clinical pathologies were mostly tubulitis t1 and isolated vascular compartment lesions. In real life, urinary CXCL10 had clinically useful diagnostic properties making it a candidate biomarker to guide allograft biopsies.

Post-traumatic inflammatory pseudotumor of the breast with atypical morphological features: A potential diagnostic pitfall. Report of a case and a critical review of the literature

Although inflammatory pseudotumor (IPT) and inflammatory myofibroblastic tumor (IMT) may share a common morphology, they are distinct clinico-pathologic entities. Unfortunately, the terms IMT and IPT are still used interchangeably, especially when lesions occur in unusual sites, including breast. All the cases of IMT/IPT involving the breast have raised spontaneously without any apparent prior injury. We herein report the first case of a post-traumatic IPT of the breast parenchyma in a 22-year-old male. Histologically, the lesion was highly cellular and composed of spindle cells arranged in a predominant fascicular pattern. Notably, mono- or multi-nucleated large pleomorphic cells were observed. Inflammatory cells, especially plasma cells and lymphocytes, were closely admixed with the spindle cell proliferation. The overall picture was reminiscent of an "IMT with atypical features", typically seen in lung, abdomen, pelvis, and retroperitoneum of children. Immunohistochemically, the spindle-shaped and large pleomorphic cells were immunoreactive to vimentin, α-smooth muscle actin, and desmin. No immunoreactivity was obtained with ALK-1 protein. The present case contributes to widening the morphological spectrum of IPT of the breast, emphasizing the possibility that a reactive lesion may contain large pleomorphic cells that may represent a potential diagnostic pitfall. Lastly, we suggest that the diagnosis of IMT of the breast should be rendered with caution when dealing with ALK-negative spindle cell lesions in adult patients, and alternative diagnoses, including IPT, should be seriously considered.

Aberrant expression of TfR1/CD71 in thyroid carcinomas identifies a novel potential diagnostic marker and therapeutic target

BACKGROUND

Type I receptor for transferrin (TfR1/CD71) is overexpressed in several malignant tumors, but no studies are available on thyroid carcinomas. Our previous comparative analyses of the relative distribution of transferrin in benign versus papillary thyroid carcinoma (PTC) tissues highlighted a marked malignancy-associated abundance of the molecule. The aim of the present study was to evaluate whether TfR1/CD71 is also differentially expressed in benign versus malignant thyroid tissues.

METHODS

Tissue samples, including benign lesions and follicular-derived carcinomas, from 241 patients and a total of 35 benign and malignant fresh specimens were assayed for TfR1/CD71 expression by reverse transcriptase-polymerase chain reaction, Western blot, and immunohistochemistry.

RESULTS

We found that transcription of TfR1/CD71 gene is constitutive in thyroid epithelia, but the mRNA is differently translated in benign and malignant tissues. Western blot revealed higher levels of TfR1/CD71 protein in malignant versus benign tissues. Immunohistochemically, most carcinomas exhibited overexpression of the receptor, predominantly in the cytoplasm of neoplastic cells. The highest expression level was detected in primary and metastatic papillary carcinomas and anaplastic carcinomas, with positive results ranging from 86% to 100% of the cases. In contrast, most benign tissues were negative, with only a minority of cases showing focal and weak immunoreactivity.

CONCLUSIONS

Our findings suggest that altered expression of TfR1/CD71 may be used as a marker helpful in distinguishing PTC from papillary hyperplasia and follicular variant PTC from benign follicular-patterned lesions. Additionally, the present observations support the rationale for the use of radiolabeled transferrin/transferrin analogs and/or anti-TfR1/CD71 antibodies for diagnostic and/or radiotherapeutic purposes in TfR1/CD71-expressing thyroid tumors.

Diffuse and extreme vacuolization of tumour cells in rectal adenocarcinoma after neoadjuvant therapy: an unusual finding

We report a case of diffuse and extreme cytoplasmic vacuolization of tumour cells in a rectal adenocarcinoma after neoadjuvant treatment. A 64-year-old man with a moderately differentiated rectal adenocarcinoma, diagnosed by endoscopic rectal biopsy, underwent surgical treatment after chemoradiotherapy. Residual tumour mass was represented by foci of neoplastic cells with the morphological features of conventional type adenocarcinoma, and surprisingly, by numerous areas consisting of several giant vacuoles, variable in size, merging to form multilocular spaces separated by a rim of cell membrane with a "plant-like" appearance. Cytoplasmic vacuolization may represent a distinct form of cell death, and pathologists should carefully consider this unusual and potentially alarming morphological change among the chemoradiotherapy-induced effects on tumour mass.

Lipoblast-like signet-ring cells in neurofibroma: a potential diagnostic pitfall of malignancy

Benign peripheral nerve sheath tumours, including neurofibroma, may occasionally contain a heterologous mature fatty component. Additional lipoblast-like cells can be occasionally identified among mature adipocytes. We report the first case of a plexiform neurofibroma from a NF1 patient containing exclusively lipoblast-like cells exhibiting morphological and immunohistochemical features identical to univaculoted lipoblasts typically seen in myxoid liposarcoma. Awareness of the possibility that an otherwise typical neurofibroma may contain lipoblast-like cells is crucial for the pathologist to avoid a misdiagnosis of malignancy. Differential diagnostic problems and histogenetic considerations are provided.

Atypical dermatofibroma with predominant epithelioid/deciduoid-like cell component. Histogenetic considerations in the wide spectrum of fibrohistiocytic dermal tumours

Atypical and epithelioid cell variants of dermatofibroma may represent a potential diagnostic pitfall. Only rarely atypical dermatofibroma may show focal epithelioid cell features. We herein report a rare case of dermatofibroma composed of a predominant (> 90%) epithelioid/deciduoid-like cell component, in which rare multinucleated bizarre cells and atypical mitoses were additional findings. Tumour was classified as "atypical dermatofibroma with predominant epithelioid/deciduoid-like cell component". The coexistence of at least two different variants, i.e. epithelioid and atypical variants, in the same dermatofibroma suggests that dermal fibrohistiocytic tumours belong to a continuous morphological spectrum. Accordingly, the morphological variants of dermatofibroma should be regarded as variations on a common basic theme. Differential diagnosis with other epitheliod cell dermal tumour- and tumour-like lesions is discussed.

Efficacy of induction therapy with ATG and intravenous immunoglobulins in patients with low-level donor-specific HLA-antibodies

Low-level donor-specific HLA-antibodies (HLA-DSA) (i.e. detectable by single-antigen flow beads, but negative by complement-dependent cytotoxicity crossmatch) represent a risk factor for early allograft rejection. The short-term efficacy of an induction regimen consisting of polyclonal anti-T-lymphocyte globulin (ATG) and intravenous immunoglobulins (IvIg) in patients with low-level HLA-DSA is unknown. In this study, we compared 67 patients with low-level HLA-DSA not having received ATG/IvIg induction (historic control) with 37 patients, who received ATG/IvIg induction. The two groups were equal regarding retransplants, HLA-matches, number and class of HLA-DSA. The overall incidence of clinical/subclinical antibody-mediated rejection (AMR) was lower in the ATG/IvIg than in the historic control group (38% vs. 55%; p = 0.03). This was driven by a significantly lower rate of clinical AMR (11% vs. 46%; p = 0.0002). Clinical T-cell-mediated rejection (TCR) was significantly lower in the ATG/IvIg than in the historic control group (0% vs. 50%; p < 0.0001). Within the first year, allograft loss due to AMR occurred in 7.5% in the historic control and in 0% in the ATG/IvIg group. We conclude that in patients with low-level HLA-DSA, ATG/IvIg induction significantly reduces TCR and the severity of AMR, but the high rate of subclinical AMR suggests an insufficient control of the humoral immune response.

Fibrous hamartoma of infancy of the labium majus: a typical lesion in an unusual site

Fibrous hamartoma of infancy is a soft tissue subdermal fibromatous tumour that characteristically occurs in the first years of life. It is histologically composed of three different components that are intimately admixed: well-defined bundles of fibro-myofibroblastic spindle-shaped cells, nodular proliferations of immature-looking mesenchymal cells set in a myxoid stroma, and mature adipose tissue. A wide intralesional and interlesional cellular composition is commonly observed. Fibrous hamartoma of infancy usually arises from subcutaneous tissue of the trunk, axilla, upper extremities and inguinal region. Only rarely has fibrous hamartoma of infancy been reported in genital organs, with only one case described in the labium majus. We report a rare case of fibrous hamartoma of infancy in the labium majus of a 1-year old female child. Ultrasonography revealed the presence of a mass-like lesion involving subcutaneous tissue, with ill-defined margins. We emphasize that fibrous hamartoma of infancy should be included in the differential diagnosis of soft tissue tumour-like and tumour lesions of the vulva in children. Awareness that fibrous hamartoma of infancy occurs at this site with irregular margins is important to avoid confusion with other lesions exhibiting a more aggressive behaviour.

Multinucleated floret-like giant cells in sporadic and NF1-associated neurofibromas: a clinicopathologic study of 94 cases

Multinucleated floret-like giant cells (MNFGCs), similar to those commonly observed in pleomorphic lipoma and giant cell fibroblastoma, have been occasionally reported in gynecomastia and neurofibromas from patients affected by neurofibromatosis type 1 (NF1). Accordingly, it has been suggested that their detection, especially in an otherwise typical neurofibroma, could be a morphological clue to diagnosis of NF1. The aim of the present study was the identification of MNFGCs in a large series (94 cases) of sporadic and NF1-associated neurofibromas, to assess if their presence may indeed be a morphological marker of NF1. Numerous MNFGCs, namely, those that were easily apparent at low magnification (x50 and x100), were identified only in 5.3% of cases. In 18.1% of cases, a low number of these cells could be observed but only after a careful search, especially at higher magnification (x200 and x400). Immunohistochemically, all MNFGCs were stained with vimentin and CD34, but not with S-100 protein. Interestingly, there was no statistically significant correlation between MNFGCs (presence or absence) and NF1 (p = 0.73), gender (p = 0.59), age (p = 0.43), and site of tumor (cutaneous vs deep-seated soft tissue; p = 0.27). Our clinicopathologic findings suggest that MNFGCs in an otherwise typical neurofibroma are not a reliable marker of NF1, likely representing a morphological reactive change of the indigenous dermal or endoneurial fibroblasts or dendritic cells in response to unknown microenvironmental stimuli.

In-vacuum optical isolation changes by heating in a Faraday isolator

We describe a model evaluating changes in the optical isolation of a Faraday isolator when passing from air to vacuum in terms of different thermal effects in the crystal. The changes are particularly significant in the crystal thermal lensing (refraction index and thermal expansion) and in its Verdet constant and can be ascribed to the less efficient convection cooling of the magneto-optic crystal of the Faraday isolator. An isolation decrease by a factor of 10 is experimentally observed in a Faraday isolator that is used in a gravitational wave experiment (Virgo) with a 10 W input laser when going from air to vacuum. A finite element model simulation reproduces with a great accuracy the experimental data measured on Virgo and on a test bench. A first set of measurements of the thermal lensing has been used to characterize the losses of the crystal, which depend on the sample. The isolation factor measured on Virgo confirms the simulation model and the absorption losses of 0.0016 +/- 0.0002/cm for the TGG magneto-optic crystal used in the Faraday isolator.

[Mammary hamartoma with atypical stromal cells: a potential diagnostic dilemma]

Hamartoma of the breast is a pseudotumoural lesion that does not usually pose diagnostic problems for the pathologist. Although atypical stromal cell (ASCs) can be encountered in several benign and malignant breast lesions, their occurrence in hamartoma has not been reported to date. The authors report a case of breast hamartoma containing numerous atypical mono- or multinucleated stromal cells within the fibro-fatty component. This unusual feature raised differential diagnostic problems with pleomorphic lipoma, well-differentiated liposarcoma and malignant phylloid tumour with a lipomatous heterologous component. Immunohistochemistry, showing positivity to vimentin and CD34, revealed that ASCs are fibroblastic in nature, and thus are likely to represent a morphological variant of the fibroblasts of the native mammary stroma.

[Carcinoma of the Bellini collecting duct in paediatric patients: a case report and review of the literature]

Collecting duct carcinoma is an uncommon variant of renal cell carcinoma that usually occurs at an earlier age compared to conventional renal cell carcinoma. It is characterised by an aggressive, often fatal, course. Renal cell carcinoma rarely occurs in paediatric patients, and is almost always in association with specific genetic alterations; the most common histotypes are the clear cell and chromophobe cell variants. Collecting duct carcinoma is rare, and only 8 cases have been reported in the literature. The authors describe the clinico-pathological features of a fatal collecting duct carcinoma in an 11-year-old boy.

Measurement of the optical parameters of the Virgo interferometer

The Virgo interferometer, aimed at detecting gravitational waves, is now in a commissioning phase. Measurements of its optical properties are needed for the understanding of the instrument. We present the techniques developed for the measurement of the optical parameters of Virgo. These parameters are compared with the Virgo specifications.