Luca Roncati

Histopathological determination of thin melanomas at risk for metastasis.

The current staging system for melanoma of the American Joint Committee on Cancer uses the Breslow thickness as the primary attribute; up to 1-mm-thick melanoma is defined as thin because it shows a good prognosis after surgical excision, with a 10-year survival rate of 85–90% in the case of tumor-free margin of at least 1 cm [1]. However, there is a subset of patients affected by thin melanoma, who develop nodal or distant metastases with worse prognosis. Although several clinical and histological features, such as sex, age, site, thickness, ulceration, and growth phase, have been considered over the years, the identification of a highrisk thin melanoma remains challenging [2,3]. For this reason, we have read with great interest the paper of Glazer et al. [4], in which the authors have investigated by quantitative histopathology 28 thin melanoma (18 patients with nonmetastatic disease and 10 patients with metastatic disease). Kariometric features have been used to discriminate between nuclei from indolent and potentially metastatic lesions. The results obtained by Glazer and colleagues support the hypothesis that thin melanoma contains two phenotypes of nuclei and only one type predominates in metastasizing thin melanomas. In fact, the authors conclude that kariometry may play a role in decision-making for patients affected by thin melanoma. Cutaneous melanoma generally evolves through three well-discernible progression steps. At first, transformedmelanocytes proliferate above the epidermal basement membrane (in-situ or the epidermal radial growth phase), then they invade the papillary dermis (microinvasive radial growth phase) and, subsequently, acquire the capacity to grow as a well-known malignancy (invasive vertical growth phase). In more detail, microinvasive melanoma is a nontumorigenic radial growth phase of cutaneous melanoma, which invades the superficial dermis, without forming a tumor nodule or papule, in the absence of regression [5]. In contrast, the microinvasive radial growth phase of cutaneous melanoma with regression may rarely metastasize and, for this reason, the lesion should be recognized and it could be also categorized as ‘microinvasive radial growth phase of uncertain tumorigenic potential’ [6–8]. The early vertical growth phase and the radial growth phase with regression are burdened by a statistical chance for distant metastases [9]. Therefore, thin melanoma includes four main histological subtypes, which reflect a specific biological behavior: the in-situ epidermal radial growth phase, the nontumorigenic microinvasive radial growth phase, the microinvasive radial growth phase with regression of uncertain tumorigenic potential, and the tumorigenic early vertical growth phase. In conclusion, thin melanoma can be considered a generic term and its subtypes should be histologically distinguished beyond its site of origin (acral versus nonacral) because they have a different prognostic relevance. The quantitative histopathology could be of greater utility if applied taking into account the four histopathological subtypes of thin melanoma shown here.

Estrogen receptor alpha overexpression in multinucleate cell angiohistiocytoma: new insights into the pathogenesis of a reactive process.

Multinucleate cell angiohistiocytoma (MCAH) is a putative reactive skin lesion, which has been reported mostly in adult female patients, and hormones have been recently suggested as a factor influencing its development. To test this hypothesis, monoclonal anti-estrogen receptor (ER) a, anti-progesterone receptor (PR), anti-Factor XIIIa, and polyclonal anti-vascular endothelial growth factor (VEGF) antibodies were applied by immunohistochemistry on a series of 21 MCAHs and, compared to 10 cases of dermatofibroma (DF) and 5 cases of chronic dermatitis presenting multinucleate cells. On normal skin surrounding the lesions and in cases of DF and chronic dermatitis, ERa was expressed in few undifferentiated and differentiated sebocytes, in few cells of anagen follicles and perifollicular mesenchymal cells, and in scattered dermal fibrocytes. In MCAHs, ERa was strongly expressed in interstitial spindle cells, spindle cells surrounding the characteristic vascular component of the lesion, and rare multinucleate cells. PR expression was restricted to sparse spindle cells and few sebocytes, whereas Factor XIIIa stained spindle cells in the dermis of normal and inflamed skin and in both MCAH and DF, and VEGF staining resulted completely negative. ERα, PR, and VEGF have been reported as poorly expressed in normal skin. In the present study, expression of ERα resulted upregulated in cases of MCAH, particularly in spindle cells, compared with that in DF cases. These findings underline the pathogenetic difference between MCAH and DF and also corroborate the suggested hypothesis of a role played by hormones, mainly ERα, in the development of this lesion. These observations could open a new strategy in the treatment of MCAH by antiestrogen therapy.

Wisely choosing thin melanomas for sentinel lymph node biopsy

To the Editor: The routine use of sentinel lymph node (SLN) biopsy (SLNB) in the management of thin melanomas is controversial. For this reason, we read with great interest the article of Wat et al in which the authors examined 1072 cases of melanoma submitted to SLNB. Among these, 171 cases were thin melanomas and 15 of them (8.8%) showed SLNB positivity. Today, the scientific community is precisely focusing on the clinical significance of different histologic subtypes of thin melanoma. The current staging system for melanoma of the American Joint Committee on Cancer uses Breslow thickness as the primary attribute and up to 1-mmthick melanoma is defined as ‘‘thin’’ because it shows good prognosis after surgical excision, with 10-year survival of 85% to 90% in case of tumor-free margin of at least 1 cm. Wat et al argued that mitotic rate does not have unequivocal utility in predicting SLNB status in thin melanomas and that there is a significant interaction between mitotic rate and Breslow depth, so the predictive value of mitotic rate on SLN positivity may be dependent on Breslow thickness. From our point of view, thin melanoma can be categorized in the following 4 histologic subtypes, which reflect specific biological attitudes: (1) epidermal (in situ) radial growth phase (RGP); (2) nontumorigenic microinvasive RGP without regression; (3) microinvasive RGP with regression of uncertain tumorigenic potential; and (4) tumorigenic early (#1.00 mm) invasive vertical growth phase (VGP). In the period 2004 to 2012, we examined SLNB of 42microinvasive RGPwithout regression, 18 microinvasive RGP with regression, and 10 early invasive VGP. Metastases to SLNwere found in only 3 cases of microinvasive RGP with regression (0.751.00 mm depth) and in 5 cases of early mitogenic invasive VGP. Therefore, ‘‘thin melanoma’’ can be considered a generic term and its subtypes should be histologically distinguished, because they have different prognostic relevance. According to our experience, SNLB should be performed in cases of microinvasive RGP with regression and early

Diagnostic approach to melanocytic lesion of unknown malignant potential.

metastatic melanomas. However, uveal or conjunctival cell cycles do not seem to be profoundly affected. To date, several characteristic genetic anomalies for tumor progression and metastasis of cutaneous as well as uveal melanoma have been identified [5]. However, unlike in cutaneous melanoma, B-Raf, Ras, or Kitmutations occur rarely in uveal melanoma, and characteristic mutations differ between uveal and cutaneous melanoma [5]. Although mutations similar to skin melanoma such as B-RAF V600 have been found in conjunctival melanomas [6], our findings underline genetic differences between conjunctival and skin melanomas as well. However, as remarkable changes regarding pigmentation were noted in the cornea and chamber angle in these animals, further investigation of the anterior segment might allow the study of mechanisms of corneal neovascularization and possibly also glaucoma.

Negative Role of the Environmental Endocrine Disruptors in the Human Neurodevelopment.

The endocrine disruptors (EDs) are able to influence the endocrine system, mimicking or antagonizing hormonal molecules. They are bio-persistent for their degradation resistance in the environment. Our research group has investigated by gas chromatography–mass spectrometry (GC–MS) the EDs presence in 35 brain samples, coming from 27 cases of sudden intrauterine unexplained death syndrome (SIUDS) and 8 cases of sudden infant death syndrome (SIDS), collected by centralization in the last year (2015). More in detail, a mixture of 25 EDs has been subjected to analytical procedure, following standard protocols. Among the target analytes, some organochlorine pesticides, that is α-chlordane, γ-chlordane, heptachlor, p,p-DDE, p,p-DDT, and the two most commonly used organophosphorus pesticides (OPPs), chlorpyrifos and chlorfenvinfos, have been found in seven and three samples, respectively. The analytical procedure used to detect the presence of environmental EDs in cortex samples has been successfully implemented on SIUDS and SIDS victims. The environmental EDs have been found to be able to overcome the placental barrier, reaching also the basal ganglia assigned to the control of the vital functions. This finding, related to the OPPs bio-persistence, implies a conceptual redefinition of the fetal–placental and fetal blood–brain barriers: not real safety barriers but simply time-deferral mechanisms of absorption.

Unexpected death: Anaphylactic intraoperative death due to Thymoglobulin carbohydrate excipient

Anaphylactic shock is a life-threatening allergic response characterized by severe hypotension, inducing tissue hypoperfusion with possible multi-organ failure and death. We describe the first case of fatal intra-operative anaphylactic shock due to prolonged infusion of Thymoglobulin during Orthotopic Liver Transplantation (OLT), resulting from recruitment of both mastocytes and basophils, activated and degranulated. Post-mortem serological analysis on a preserved, pre-OLT sample of the patients blood revealed specific IgE against carbohydrate cross-reactive determinants (CCDs), such as MUXF3 and nAna c2, proving that anaphylactic reaction was triggered by the Thymoglobulin carbohydrate excipient (sugar alcohol mannitol), rather than anti-thymocyte globulin itself. Our findings are consistent with scientific data reported in the literature, where only one case of non-fatal anaphylaxis to Thymoglobulin has been described, despite the existence of proven cases of anaphylactic reaction to mannitol. This case highlights the need to pay particular attention in future not only to active substances but also to drug excipients, above all during intra-operative drug delivery. In view of the important role played by basophils in this kind of anaphylaxis, the basophil activation test (BAT) could prove useful in preventing anaphylactic death from CCDs.

Impaired orexin receptor expression in the Kölliker–Fuse nucleus in sudden infant death syndrome: possible involvement of this nucleus in arousal pathophysiology

Objectives: As well known, the sudden infant death syndrome (SIDS) is characterized by the sudden death of a seemingly healthy infant during sleep, frequently resulted from a deficit in arousal phase. Awakening from sleep requires a fully developed and functioning neuronal respiratory network to modulate the ventilation as needed. The pontine Kölliker–Fuse nucleus (KFN) plays a pivotal role in breathing control, thanks to its interconnections with the widespread serotonin and noradrenaline neurons in the brainstem. Numerous studies to date have focused on the implication of orexin, a neuropeptide synthesized by neurons of the lateral hypothalamus, with major projections to the brainstem raphé nuclei and locus coeruleus, in arousal, a neurobiological process closely linked to breathing modifications. The aim of our research has been to demonstrate that also the KFN is a fundamental component of the orexin system, actively involved in arousal. Methods: We have evaluated the expression and distribution of the orexin receptors (orexin-1 and orexin-2 receptors) particularly in the rostral pons, where the KFN is located, of 25 SIDS cases and 18 controls. Results: An intense orexin-1 innervation around the KF neurons has been detected in almost all the controls and only in 20% of SIDS cases. Discussion: On the basis of these results, we believe that: (1) the KFN plays a leading role not only in providing a regular breathing rhythm but also in the coordination of the sleep-to-wake transition; (2) a defective orexin expression in the KFN could prevent arousal, thus assuming a crucial importance in causing SIDS.

Developmental neuropathology of brainstem respiratory centers in unexplained stillbirth: What’s the meaning?

Stillbirth is one of the most stressful life events affecting over 3 million pregnancies per year throughout the world. An accurate autopsy of the stillborn fetus, including the placenta and umbilical cord examination, should be performed promptly after delivery. A thorough maternal history also should be taken, including exposures to risk factors. In many cases a death cause, attributable to fetal, maternal, or placental pathology, is clearly identified. However, in 50% or more of cases the cause remains unknown.

The First 5-Year-Long Survey on Intrauterine Unexplained Sudden Deaths from the Northeast Italy.

ABSTRACT Purpose: Sudden intrauterine unexplained death syndrome (SIUDS) represents one of the main open issues in the scientific and social setting of the modern medicine, and our efforts have aimed to understand its possible causes and risk factors. Methods: A 43-case series of consecutive unexplained fetal deaths coming from Northeast Italy, collected in a 5-year period (2011–2015), has been submitted to an in-depth investigation, based on neuropathological and cardiopathological examinations, immunohistochemistry for neuronal nuclear antigen (NeuN), genetic characterization for the serotonin transporter (5-HTT) gene polymorphisms, and toxicological environmental analyses. Results: The overall survey from the neuropathological findings highlights one or more congenital morphological abnormalities of the autonomic nervous system in 77% of cases of sudden fetal deaths. Conclusions: From our results emerges the need to perform a complete autopsy of all SIUDS victims with an in-depth examination of the neuronal centers of the brainstem, which modulate the vital functions.

Prognostic Factors for Breast Cancer: an Immunomorphological Update

The prognostic variability recorded within homogeneous groups of patients for anatomo-clinical disease stages has led to a more detailed biological characterization of breast cancer. Recently, the attention of the scientific community has focused on the role of tumor-infiltrating lymphocytes (TILs). Therefore, the need of an in-depth immunomorphological characterization of TILs has been emerged. The presence of TILs has been retrospectively investigated in 113 female cases of ductal carcinoma. An immunohistochemical investigation with CD3, CD4, CD8, CD20, CD56, granulysin, perforin-1, granzyme-B and TIA-1 was performed according to the standard procedures on all 17 cases with TILs evidence. TILs consisted of T and B lymphocytes: the prevalent population showed a T immunoprofile with a CD8-immunopositive killer subpopulation (Tk), close-linked to carcinomatous cells, and a CD4-immunopositive helper subpopulation (Th), inside the tumor. A time sequence (firstly T, then B) has been disclosed. Granulysin, perforin, granzyme-B and TIA-1 were expressed by Tk cells. The activated Tk cells secrete these mediators as a result of the binding to the tumor target cell, causing its lytic planned death. The cytotoxicity supported by Tk cells appears an important favorable prognostic factor. Therefore, a graduation system for TILs in breast cancer has been here proposed (absent, non-brisk, brisk).