Neuroendocrine and squamous cell phenotypes of NUT carcinoma are potential diagnostic pitfalls that discriminating it from mimickers, such as small cell and squamous cell carcinoma.

INTRODUCTION: NUT carcinoma is a rare cancer associated with a poor prognosis. Because of its rarity, its diagnosis is challenging and is usually made by excluding other diagnoses. Immunohistochemical analysis is a reliable technique that contributes to a correct diagnosis, but overestimating the expression of neuroendocrine (NE) markers may result in an incorrect diagnosis. In this study, we established the immunohistochemical phenotypes of NUT carcinoma compared with tumors that mimic its phenotype to identify potential diagnostic pitfalls. METHODS: Eight cases of NUT carcinoma were examined along with eight basaloid squamous cell carcinomas and thirteen cases of small cell carcinoma using an immunohistochemical panel consisting of various antibodies. RESULTS: Of the eight NUT carcinomas, three patients had a smoking history. All the cases examined for INSM1 were positive (6/6, 100%), although the staining was somewhat weak. Among the NE markers, synaptophysin was variably positive in two NUT carcinomas (2/6, 33%); however, all cases were negative for ASCL1, chromogranin A, and CD56. Moreover, the squamous cell markers, p40 and CK5/6, were weakly expressed in 4/6 (67%) and 3/6 (50%) of the NUT carcinomas, respectively. CONCLUSIONS: For tumors with an ambiguous morphology, applying the neuroendocrine phenotype of NUT carcinoma may be misleading; particularly, when distinguishing it from small-cell carcinoma. Similarly, null or weak expression of squamous cell markers may be observed in NUT carcinoma, but this differs from squamous cell carcinoma, which consistently demonstrates strong positivity for squamous cell markers.

Neuroendocrine neoplasms of the breast: a review of literature.

Primary neuroendocrine neoplasms (NENs) of the breast are characterized by neuroendocrine architectural and cytological features, which must be supported by immunohistochemical positivity for neuroendocrine markers (such as Chromogranin and Synaptophysin). According to the literature, making a diagnosis of primary neuroendocrine breast cancer always needs to rule out a possible primary neuroendocrine neoplasm from another site. Currently, the latest 2022 version of the WHO of endocrine and neuroendocrine neoplasms has classified breast NENs as well-differentiated neuroendocrine tumours (NETs) and aggressive neuroendocrine carcinomas (NECs), differentiating them from invasive breast cancers of no special type (IBCs-NST). with neuroendocrine features. The current review article describes six cases from our series and a comprehensive review of the literature in the field of NENs of the breast.

The Significance of Insulinoma-Associated Protein 1 in the Pathological Diagnosis of Small-Cell Lung Cancer in Biopsy Specimens.

Objective: Our purpose was to investigate the clinicopathological diagnostic value of immunohistochemical antibody for insulinoma-associated protein 1 (INSM1) in biopsy specimens of SCLC. Methods: Biopsy specimens of SCLC diagnosed at the pathology department of Tangshan Gongren Hospital from January 2022 to June 2023 were selected. INSM1 expression was detected and compared with conventional neuroendocrine markers synaptophysin (SYP), chromogranin A (CHGA), and CD56 regarding expression sensitivity and specificity. Results: The sensitivity of INSM1 expression was significantly higher than that of CHGA (95% vs 50%, P = .000), but there was no statistically significant difference in the specificity of INSM1, SYP, CHGA, and CD56 expression (100% vs 94% vs 98% vs 92%, respectively, P = .241, 1.000, .126). Conclusions: INSM1 antibody shows high sensitivity and specificity in the expression of SCLC and serves as a reliable immunohistochemical marker in the clinicopathological diagnosis of SCLC in biopsy specimens.

Non-functional paraganglioma of urinary bladder managed by transurethral resection

ABSTRACT Purpose As a rare bladder tumor, paraganglioma of the urinary bladder (PUB) is frequently misdiagnosed as bladder cancer, particularly for the non-functional type. To date, transurethral resection remains a controversial treatment for non-functional PUB. This study aimed to identify the clinical features, pathological characteristics, prognosis, and safe/effective treatment of non-functional PUB using transurethral resection of the bladder tumor (TURBT). Materials and Methods The clinical records, radiological data, pathological characteristics and follow-up times were retrospectively reviewed in 10 patients with clinically and pathologically proven non-functional PUB in our hospital from January 2008 to November 2016. All patients underwent TURBT treatment. Results The incidence of non-functional PUB in patients with bladder cancer was 0.17%. The mean age at diagnosis was 44.5 ± 13.6 years (range, 29-70 years), and the patient population had a female: male ratio of 3: 2. No patients had excess catecholamine (CA) whilst four patients had painless hematuria. All neoplasms were completely resected via TURBT. The majority of samples were positive for immunohistochemical markers including chromogranin A (CgA) and Synaptophysin (Syn), but were negative for cytokeratins (CKs). Only a single recurrence was observed from the mean follow-up period of 36.4 ± 24.8 months. Conclusion Complete TURBT is a safe and efficient treatment that serves both diagnostic and therapeutic purposes. Histopathological and immunohistochemistry examinations are mandatory for diagnostic confirmation. Long-term follow-up is recommended for patients with non-functional PUB.

Obstrucción intestinal secundaria a invaginación yeyunal como forma de presentación de paraganglioma gangliocítico / Bowel obstruction secondary to yeyunal intussusception due to gangliocytic paraganglioma

No disponible

Possible roles of COX-1 in learning and memory impairment induced by traumatic brain injury in mice

People who suffer from traumatic brain injury (TBI) often experience cognitive deficits in spatial reference and working memory. The possible roles of cyclooxygenase-1 (COX-1) in learning and memory impairment in mice with TBI are far from well known. Adult mice subjected to TBI were treated with the COX-1 selective inhibitor SC560. Performance in the open field and on the beam walk was then used to assess motor and behavioral function 1, 3, 7, 14, and 21 days following injury. Acquisition of spatial learning and memory retention was assessed using the Morris water maze on day 15 post-TBI. The expressions of COX-1, prostaglandin E2 (PGE2), interleukin (IL)-6, brain-derived neurotrophic factor (BDNF), platelet-derived growth factor BB (PDGF-BB), synapsin-I, and synaptophysin were detected in TBI mice. Administration of SC560 improved performance of beam walk tasks as well as spatial learning and memory after TBI. SC560 also reduced expressions of inflammatory markers IL-6 and PGE2, and reversed the expressions of COX-1, BDNF, PDGF-BB, synapsin-I, and synaptophysin in TBI mice. The present findings demonstrated that COX-1 might play an important role in cognitive deficits after TBI and that selective COX-1 inhibition should be further investigated as a potential therapeutic approach for TBI.

Diagnóstico definitivo de los tumores neuroendocrinos (TNE) mediante PAAF ecodirigida por ultrasonografía endoscópica (USE) / No disponible

Introducción: la localización y diagnóstico de los tumores neuroendocrinos (TNE) es difícil. La ultrasonografía endoscópica (USE) tiene un papel significativo en la detección de TNE sospechados por la clínica u otras técnicas de imagen, así como en la localización exacta y confirmación citológica mediante USEPAAF. Objetivo: valorar la utilidad y precisión de la PAAF-USE en el diagnóstico diferencial y de confirmación de los TNE, en una revisión retrospectiva de la experiencia de nuestro grupo. Pacientes y métodos: de un total de 55 enfermos con sospecha de TNE a los que se le practicó USE radial o sectorial, se detectaron 42 tumores en 40 casos. En 16 casos con sospecha de TNE funcionantes (trastornos hormonales: 6 casos) y no funcionantes (10 casos), se les practicó USE-PAAF con 22 G. En todos se efectuó Ki 67 o inmunocitoquímica (ICQ). Hubo confirmación quirúrgica en 9 casos (5 M y 4 V), con una media de edad de 51 años (rango: 41-81 años). Los tumores se localizaban todos en el páncreas, excepto uno en el mediastino y uno en el recto, con un tamaño medio de 19 mm (rango: 10-40 mm). Resultados: no hubo complicaciones atribuibles a la PAAF. La sensibilidad fue del 100% (8/8), y la precisión y el VPP fue del 89% (8/9), ya que hubo un falso positivo que en el estudio cito - lógico sugirió el diagnóstico de TNE pero que su resección quirúrgica confirmó el diagnóstico de tumor sólido seudopapilar del páncreas. Conclusiones: la USE-PAAF con 22 G de los TNE posee una alta sensibilidad y VPP en la confirmación citológica de estos pacientes, con muy escasas complicaciones(AU)

Background: the detection and diagnosis of neuroendocrine tumors (NETs) is challenging. Endoscopic ultrasonography (EUS) has a significant role in the detection of NETs suspected from clinical manifestations or imaging techniques, as well as in their precise localization and cytological confirmation using EUS-Fine-needle aspiration-puncture (FNA). Objective: to assess the usefulness and precision of EUSFNAP in the differential diagnosis and confirmation of NETs, in a retrospective review of our experience. Patients and methods: in a total of 55 patients with suspected NETs who underwent radial or sectorial EUS, 42 tumors were detected in 40 cases. EUS-FNA using a 22G needle was performed for 16 cases with suspected functional (hormonal disorders: 6 cases) and non-functional NETs (10 cases). Ki 67 or immunocytochemistry (ICC) testing was performed for all. There was confirmation in 9 cases (5 female and 4 male) with a mean age of 51 years (range: 41-81 years). All tumors were located in the pancreas except for one in the mediastinum and one in the rectum, with a mean size of 19 mm (range: 10-40 mm). Results: there were no complications attributable to FNA. Sensitivity was 100% and both precision and PPV were 89%, as a false positive result suggested a diagnosis with NET during cytology that surgery finally revealed to be a pancreatic pseudopapillary solid tumor. Conclusions: EUS-FNA with a 22G needle for NETs has high sensitivity and PPV at cytological confirmation with few complications(AU)

The immunomodulator glatiramer acetate influences spinal motoneuron plasticity during the course of multiple sclerosis in an animal model

The immunomodulador glatiramer acetate (GA) has been shown to significantly reduce the severity of symptoms during the course of multiple sclerosis and in its animal model - experimental autoimmune encephalomyelitis (EAE). Since GA may influence the response of non-neuronal cells in the spinal cord, it is possible that, to some extent, this drug affects the synaptic changes induced during the exacerbation of EAE. In the present study, we investigated whether GA has a positive influence on the loss of inputs to the motoneurons during the course of EAE in rats. Lewis rats were subjected to EAE associated with GA or placebo treatment. The animals were sacrificed after 15 days of treatment and the spinal cords processed for immunohistochemical analysis and transmission electron microscopy. A correlation between the synaptic changes and glial activation was obtained by performing labeling of synaptophysin and glial fibrillary acidic protein using immunohistochemical analysis. Ultrastructural analysis of the terminals apposed to alpha motoneurons was also performed by electron transmission microscopy. Interestingly, although the GA treatment preserved synaptophysin labeling, it did not significantly reduce the glial reaction, indicating that inflammatory activity was still present. Also, ultrastructural analysis showed that GA treatment significantly prevented retraction of both F and S type terminals compared to placebo. The present results indicate that the immunomodulator GA has an influence on the stability of nerve terminals in the spinal cord, which in turn may contribute to its neuroprotective effects during the course of multiple sclerosis.

Morphometric evaluation of NB84, synaptophysin and AgNOR is useful for the histological diagnosis and prognosis in peripheral neuroblastic tumors (pNTs)

OBJECTIVE: To study the importance of NB84, synaptophysin and AgNOR and explore the quantitative association of these factors with diagnosis and outcome as well as the association between NB84 and AgNOR and other tumor and stromal factors in twenty-eight peripheral neuroblastic tumors. METHODS: We assessed AgNORs, NB84, synaptophysin and several other markers in tumor tissues from 28 patients with primary neuroblastic tumors. The treatment included: surgery for stage 1, chemotherapy and bone marrow transplantation for most of stages 3 and 4. Histochemistry, immunohistochemistry and morphometry were used to evaluate the amount of tumor staining for AgNOR, NB84 and synaptophysin; the outcome for our study was survival time until death due to recurrent neuroblastic tumors. RESULTS: Only stage (p<0.01), AgNOR (p<0.01), NB84 (p<0.01) and synaptophysin (p=0.01) reached statistical significance as prognostic indicators. CONCLUSIONS: Determination of NB84 and synaptophysin are useful tools for the diagnosis of peripheral neuroblastic tumors The association of the evaluation of AgNOR expression by the tumor cells may provide an important contribution to the prognostic evaluation and management approach of the patients.

OBJETIVO: Estudar a importância dos marcadores NB84 e AgNOR e explorar as relações quantitativas entre esses marcadores com o diagnóstico e prognóstico assim como as relações entre NB84 e AgNOR e outros marcadores tumorais e estromais em 28 tumores neuroblásticos periféricos. MÉTODOS: Examinamos AgNOR, NB84 e sinaptofisina e vários outros marcadores em tecidos tumorais de vinte e oito pacientes com tumors neuroblásticos primários. Tratamento dos pacientes incluiu: cirurgia para o estágio 1, quimioterapia e transplante de medula óssea para a maioria dos pacientes nos estágios 3 e 4. Utilizamos histoquímica, imunohistoquímica e morfometria para avaliar a intensidade e extensão de expressão do AgNOR, NB84 e sinaptofisina, tendo o prognóstico dos pacientes incluído o tempo de sobrevida até a morte por recurrência dos tumores neuroblásticos. RESULTADOS: Estadiamento (p<0.01), AgNOR (p<0.01), NB84 (p<0.01) e sinaptofisina (p=0.01) foram marcadores independents de sobrevida. CONCLUSÕES: A determinação dos marcadores NB84 e sinaptofisina mostrou-se como uma ferramenta útil no diagnóstico dos tumors neuroblásticos periféricos; a associação desses marcadores à expressão de AgNOR pelas células tumorais contribuiu à determinação do prognóstico e estabelecimento do protocolo terapêutico para os pacientes.

Extrapulmonary Small Cell Carcinoma of the Liver: Clinicopathological and Immunohistochemical Findings

Patients with primary small cell carcinoma of the liver have rarely been described in medical literature. Knowledge of clinical, pathological and immunohistochemical properties remains limited. We described an 82-year-old female patient with primary small cell carcinoma of the liver. Histologically, the tumor showed typical morphology of a pulmonary small cell carcinoma. Immunohistochemically, the tumor revealed neuroendocrine differentiation; positive reaction for chromogranin, synaptophysin, CD56, and neuron specific enolase. The tumor was also positive for TTF-1 and c-kit but completely negative for hepatocyte, carcinoembryonic antigen, cytokeratin 7; 19; and 20. Herein, we discussed the clinical, pathological and immunohistochemical findings of extrapulmonary small cell carcinoma of the liver and reviewed the relevant literature.

Expression of nestin and vimentin in gliomatosis cerebri / Expressão de nestina e vimentina na gliomatosis cerebri

Gliomatosis cerebri (GC) is a rare form of CNS neoplasia in which there is diffuse involvement of the nervous tissue with or without the presence of tumor mass. The origin of the tumor is unknown, nor whether it represents a disease with diffuse onset or infiltration from a neoplastic focus. Here we studied the histopathologic characteristics of 6 cases with a diagnosis of GC and performed an immunohistochemical analysis using glial fibrillary acidic protein (GFAP), synaptophysin, nestin and vimentin. Most tumor cells were negative for GFAP, even though there were foci of positivity for this marker in all cases. We detected the presence of many positive cells for nestin and vimentin in all studied samples. The presence of these cells may indicate origin of the tumor from undifferentiated cells with a high degree of mobility.

A gliomatosis cerebri (GC) é uma forma rara de neoplasia do sistema nervoso central em que existe o envolvimento difuso do tecido nervoso com ou sem a presença de massa tumoral. A origem do tumor é incerta, bem como se representa uma doença de início difuso ou uma infiltração a partir de um foco de neoplasia. Foram estudadas as características histopatológicas de seis casos com diagnóstico de GC e realizada imuno-histoquímica utilizando-se GFAP, sinaptofisina, nestina e vimentina. A maioria das células tumorais mostrou-se negativa para GFAP, apesar de existirem focos de positividade para este marcador em todos os casos. Observamos muitas células positivas para nestina e para vimentina em todas as amostras estudadas. Estas células poderiam indicar a origem do tumor em células multipotenciais com alto grau de mobilidade.

The Expression of p53, p16, Cyclin D1 in Esophageal Squamous Cell Carcinoma and Esophageal Dysplasia / 대한소화기학회지

BACKGROUND/AIMS: p53 is known to play a central role in sensing and signaling for the growth arrest and apoptosis in cells with DNA damage. Mutation of p53 is a frequent event in esophageal squamous cell carcinoma (ESCC). p16 protein binds to cyclin dependent kinase 4 (CDK4) inhibiting the ability of CDK4 to interact with cyclin D1, and stimulates the passage through the G1 phase of cell cycle. We observed the expression patterns and frequencies of p53, p16, and cyclin D1 in esophageal dysplasia and in esophageal squamous cell carcinomas. METHODS: In 15 patients of ESCC, 5 patients of esophageal dysplasia and 5 volunteers with normal esophagus, tissue specimens were taken from esophageal lesions during the operation or endoscopic examination. We used specific monoclonal antibodies for p53 protein, p16INK4 protein and cyclin D1. Immunoreactivity was scored. RESULTS: Mean age of all groups was 66 years old (range 47-93) and men to women ratio was 19:1. p53 mutation was observed in 87% (13/15) of ESCC, in 80% (4/5) of esophageal dysplasia, in 0% (0/5) of normal mucosa (p=0.001). p16 expression was seen in 40% (2/5) of esophageal dysplasia, 27% (4/15) of ESCC and 100% (5/5) of normal mucosa (p=0.016). Cyclin D1 expression was not significantly different among 20% (1/5) of esophageal dysplasia, 53% (8/15) of ESCC and 20% (1/5) of normal mucosa. Either the expression of p53 mutation or the loss of p16 occurred in 80% (4/5) of esophageal dysplasia and in 93% (14/15) of ESCC. CONCLUSIONS: The expression of p53 mutation and the loss of p16 might play a central role in the pathogenesis of esophageal squamous cell carcinoma (ESCC), and contribute to the development of precancerous lesion such as dysplasia. In addition, there is a possibility that the mutations of p53 and p16 silencing would be the early events in ESCC development.

Clinicopathologic Characteristics of Colorectal Neuroendocrine Tumor / 대한소화기학회지

BACKGROUND/AIMS: Colorectal neuroendocrine carcinoma is a rare neoplasm exhibiting fulminant progression and having poor prognosis. The purpose of this study is to verify the clinicopathologic characteristics of colorectal neuroendocrine carcinoma. METHODS: From June 1997 to December 2004 at Asan Medical Center, ten patients were originally identified as colorectal neuroendocrine carcinoma on the basis of H&E and immunohistochemical staining (IHC). Carcinoid tumors were excluded in this study. Medical records of thirteen patients were reviewed retrospectively. RESULTS: Ten patients (0.2%) with colorectal neuroendocrine tumors were identified from 4,512 patients with colorectal cancer; ten neuroendocrine carcinomas and three adenocarcinomas with neuroendocrine differentiation. Their median age was 60 (41-83) years. The subjects consisted of six males and seven females. Nine tumors were located in the rectum, two in the sigmoid, and each one in the transverse colon and cecum, respectively. Nine of ten neuroendocrine carcinomas expressed synaptophysin, but chromogranin A were expressed in four. All patients were advanced at the time of diagnosis, with AJCC TNM staging: stage IIIB (n=2), stage IIIC (n=3), and stage IV (n=8). The median survival for ten neuroendocrine carcinomas and three adenocarcinomas with neuroendocrine differentiation were 16.4 months and 30 months, respectively. Five patients who received chemotherapy showed median survival of 32 months (stage III) and 17.5 months (stage IV), whereas other five patients without chemotherapy died with a median survival of 6.2 months. CONCLUSIONS: Colorectal neuroendocrine tumors are extremely rare showing aggressive behavior biologically, i.e fulminant early distant metastasis. Nevertheless, improved survival may be achieved by aggressive multimodality therapy.

Carcinoma neuroendocrino de cérvix uterino: descripción de 2 casos clínicos, uno de ellos asociado a gestación. Revisión de la bibliografía / Neuroendocrine carcinoma of the uterine cervix: report of 2 cases, one of them complicated by pregnancy. Literature review

El carcinoma neuroendocrino de cérvix uterino (CNCU) es una entidad infrecuente asociada a un comportamiento agresivo. El tratamiento óptimo no está definido claramente. Rara vez se asocia a una gestación. Se presentan 2 casos de CNCU tratados en nuestro departamento, el primero de ellos asociado a un embarazo

Neuroendocrine carcinoma of the uterine cervix is a rare disease with very aggresive behavior. The optimal initial therapeutic approach has not yet been clearly defined. It rarely is complicated by pregnancy. We present 2 cases of this entity treated in our department, the first associated to gestation

Tumor neuroectodérmico primitivo renal. Reporte de un caso / Primitive neuroectodermal kidney tumor. Case report

Antecedentes: El tumor neuroectodérmico primitivo(TNEP) es un tumor de células redondas que se presenta principalmenteen tejidos blandos; excepcionalmente se encuentraen tracto intestinal, pelvis, retroperitoneo y riñón. Métodos:El espécimen quirúrgico renal, fue fijado en formol al 10%, eincluido en parafina. El estudio de inmunohistoquímica comprendiólos siguientes anticuerpos: enolasa neuronal específica,sinaptofisina y mic2. Resultados: Reportamos el caso deun hombre de 32 años de edad atendido en el hospital universitariosan Vicente de Paúl, Medellín con diagnóstico de tumorrenal izquierdo, sin hematuria macroscópica al momento deingreso ni metástasis a distancia documentadas, dolor de difícilmanejo y sensación de masa abdominal a nivel del flancoizquierdo. Con dicho diagnóstico se lleva el paciente a cirugíapara realizar nefrectomía radical, observando en el acto quirúrgico,gran compromiso ganglionar aortocavo y peripancreático.Sin ninguna posibilidad de ofrecer coadyuvancia de tiporadio o quimioterapia durante el post operatorio debido a suevolución clínica, fallece a los 2 meses postoperatorios conenfermedad diseminada. En el estudio anatomopatológico seevidencia proliferación renal difusa de células redondas conformación de rosetas, con infiltración de la cápsula haciaregión abdominal, y ganglios locales comprometidos. El estudiode inmunohistoquímica resulta positivo para enolasa neuronalespecífica, sinaptofisina y mic2. Conclusiones: En lospacientes con diagnóstico de tumor renal, se debe llevar a caboun estudio histopatológico completo, incluyendo el estudio deinmunohistoquímica antes de realizar una cirugía radical,debido al mal pronóstico de los TNEP, que pese a tener unabaja frecuencia que conlleva a una mortalidad por encima del80% (5). En la actualidad por medio del estudio inmunohistoquímicocon sobre expresión del gene MIC2, detección detranslocación especifica, estudios de hibridización con fluoresceínay trascripción reversa de polimerasa podemos diferenciarcon certeza los TNEP primarios de los sarcomas deEwing y otros sarcomas de células redondeadas

Background: Primitive Neuroectodermal Tumor(PNET) is composed of small round cells and mainly foundin soft tissues outside the central nervous system. However,urinary system is rarely involved. Patients and methods:A case of a 32 year old male complaining of severe pain inthe left flank was diagnosed of a left renal tumor at theHospital Universitario San Vicente de Paul, Medellin,Colombia. A palpable lump at left abdominal flank wasnoticed. There was no history of hematuria or documentedmetastatic lesions. Radical nephrectomy was performed. Adiffuse enlargement of the left kidney with prominentlymph nodes around aortic, vena cava and pancreas werefound. Because of the bad patient’s clinical condition, neitherradio nor chemotherapy was offered. Patient died 2months after surgery with disseminated metastases. Nephrectomyspecimen was fixed in 10% formaldehyde andsamples were paraffin embedded. An immunohistochemicalstudy was performed including the following antibodies:NSE, synaptophysin and mic2. Results: Histologicalexamination showed a diffuse renal proliferation of roundcells with rosette formations. Invasion of the renal capsuleand metastasis to lymph nodes were noticed. Immunohistochemicalstudy reveals positivity for NSE, synaptophysinand mic2. Conclusions: In patients diagnosed of renaltumor, a complete hispathological study should be performed,including an immunohistochemical study before performingradical surgery. Although Primitive PNET is veryinfrequent, its mortality rate reaches 80%. Immunohistochemistry(mic2), specific translocation, flourescein andreversal transcription polimerase, can differentiate primaryPNET from other round cell tumors

Lumbar region intra-spinal primitive neuroectodermal tumour (PNET) combined with neurofibromatosis type 1

Primitive neuroectodermal tumours (PNET) are aggressive neoplasias that are diagnosed, usually, in infancy. Their appearance in adulthood is rare and, exceptionally, in association with neurofibromatosis type I (NF-1). We present a case of a 37 year-old man with NF-1 combined with PNET in the intra-arachidial lumbar region. Diagnosis was by Nuclear Magnetic Resonance (NMR) and biopsy of soft tissue mass which showed a PNET with undifferentiated round cells and immunohistochemically positive for CD99, neurone-specific enolase, synaptophysin and LEU-7. Surgery was performed with spine decompression and resection of 80% of the tumour, with symptoms improvement. Radiotherapy was administered on the lumbosacral column, but only up to 30 Gy because of severe actinic enteritis and pan-cytopenia grade III. Six months later, the patient was hospitalized with deterioration in his overall clinical status with multi-organ involvement. The patient died and an autopsy was performed. The initial treatment of the PNET is surgery and, if possible, the radical extirpation of the tumour. Administration of radiotherapy and chemotherapy appears to increase survival. We comment on the clinical, histological, cytological and immunohistochemical aspects together with a review of the literature. To the best of our knowledge this is the first documentation of such a case