Primary Ovarian Small Cell Carcinoma of Pulmonary Type: Analysis of 6 Cases and Review of 31 Cases in the Literatures / 中国医学科学杂志(英文版)

Objective Primary ovarian small cell carcinoma of pulmonary type (SCCOPT) is a rare ovarian tumor with a poor prognosis. The platinum-based chemotherapy is the standard treatment. However, there is little research on the clinical characteristics of SCCOPT and the potential benefits of other treatments due to its low incidence. The study aims to investigate clinicopathological characteristics and treatment of SCCOPT.Methods We summarized the clinical, imaging, laboratorical and pathological characteristics of 37 SCCOPT cases, in which 6 cases were admitted to the Gansu Provincial Hospital from the year of 2008 to 2022 and 31 cases reported in 17 English and 3 Chinese literatures.Results The median age of the studied SCCOPT cases (n=37) was 56.00 (range, 22-80) years. Almost 80% of them had a stage Ⅲ or Ⅳ tumor. All patients underwent an operation and postoperative chemotherapy. Nevertheless, all cases had a poor prognosis, with a median overall survival time of 12 months. Immunohistochemically, the SCCOPT of all patients showed positive expressions of epithelial markers, such as CD56 and sex-determining region of Y chromosome-related high-mobility-group box 2 (SOX-2), and negative expressions of estrogen receptor, progesterone receptor, vimentin, Leu-7, and somatostatin receptor 2. The tumor of above 80% cases expressed synaptophysin. Only a few cases expressed neuron-specific enolase, chromogranin A, and thyroid transcription factor-1. Conclusions SCCOPT had a poor prognosis. SOX-2 could be a biomarker to be used to diagnose SCCOPT.

Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region / 中华口腔医学杂志

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.

Neuroendocrine tumors of the urinary bladder - Report of two cases

Primary paraganglioma and small cell neuroendocrine carcinoma of the urinary bladder are rare tumors, comprising 0.05% of all bladder tumors and <1% of all malignant bladder tumors, respectively. These tumors can be the cause of a diagnostic dilemma or misdiagnosis on morphology. Paraganglioma is often mistaken for urothelial carcinoma and small cell carcinoma for poorly differentiated carcinoma or lymphoma. Herein, we report a case of primary paraganglioma and another of a small cell carcinoma of the urinary bladder and discuss their closest differential diagnoses. The diagnostic pitfalls should be kept in mind so that correct, timely diagnosis of these entities can be made due to implications in the management and prognosis.

Expression and significance of CK5/6, P63, P40, CK7, TTF-1, NapsinA, CD56, Syn and CgA in biopsy specimen of squamous cell carcinoma, adenocarcinoma and small cell lung carcinoma / Expresión y significado de CK5/6, P63, P40, CK7, TTF-1, NapsinA, CD56 Syn y CgA en muestras de biopsia de carcinoma de células escamosas, adenocarcinoma y carcinoma de células pequeñas de pulmón

Nine tumor and various potential biomarkers were measured and combined the information to diagnose disease, all patients accepted fiber bronchoscopy brush liquid based cytologyand histopathology examination in order to reliably detect lung cancer. The samples from 314 Chinese lung cancer patients were obtained and CK5/6, P63, P40, CK7, TTF-1, NapsinA CD56, Syn and CgA were measured with the immunohistochemical SP method and analyzed correlation of the expression of these markers with pathological and clinical features of squamous cell carcinoma, adenocarcinoma, and small cell lung carcinoma. Squamous cell carcinoma, adenocarcinoma and small cell carcinoma were 61 cases, 114 cases and 139 cases,CK5/6 and P63 expression were more frequent in squamous cell carcinoma, with sensitivity and specificity of 77.05 % and 96.44 %, 83.61 % and 88.93 %,and compared with adenocarcinoma and small cell carcinoma difference was statistically significant (P<0.05), The incidences of a positive P40 expression were 100 % in squamous cell carcinoma, with specificity of 98.81 %.CK7, TTF-1 and NapsinA expression were more frequent in adenocarcinoma, with sensitivity and specificity of 85.09 % and 78.69 %, 79.82 % and 93.44 %, 56.14 % and 95.08 %, and compared with squamous cell carcinoma and small cell carcinoma difference was statistically significant (P<0.05). TTF-1, Syn, CgA and CD56 expression were more frequent in adenocarcinoma, with sensitivity and specificity of 86.33 % and 93.44 %, 89.21 % and 98.36 %, 74.10 % and 100 %, 96.40 % and 96.72 %. The combined detection of CK5/6, P63 and P40 were more useful and specific in differentiating squamous cell carcinoma. CK7, TTF-1 and NapsinA were more useful and specific in differentiating lung adenocarcinoma. The impaired CD56, TTF-1, Syn and CgA reflects the progression of small cell lung cancer.

Se midieron tumores y utilizaron nueve biomarcadores potenciales y se analizó la información para diagnosticar la enfermedad. A todos los pacientes se les realizó citología en líquido con broncoscopía de fibra y examen histopatológico para detectar de manera confiable el cáncer pulmonar. Se obtuvieron muestras de 314 pacientes chinos con cáncer de pulmón y CK5 / 6, P63, P40, CK7, TTF-1, Napsina A, CD56, Syn y CgA se midieron a través de histoquímica SP y analizaron la correlación de la expresión de estos marcadores con características patológicas y clínicas de carcinoma de células escamosas, adenocarcinoma y carcinoma de células pequeñas en el cáncer de pulmón. El carcinoma de células escamosas, el adenocarcinoma y el carcinoma de células pequeñas fueron 61 casos, 114 casos y 139 casos, respectivamente, la expresión de CK5 / 6 y P63 fueron más frecuentes en el carcinoma de células escamosas, con una sensibilidad y especificidad del 77,05 % y 96,44 %, 83,61 % y 88,93 %, y en comparación con el adenocarcinoma y el carcinoma de células pequeñas, la diferencia fue estadísticamente significativa (P <0,05). La incidencia de ap la expresión positiva P40 fue del 100 % en el carcinoma de células escamosas, con una especificidad del 98,81 %. La expresión de CK7, TTF-1 y NapsinA fueron más frecuentes en el adenocarcinoma, con una sensibilidad y especificidad del 85,09 % y 78,69 %, 79,82 % y 93,44 %, 56,14 % y 95,08 %, y en comparación con el carcinoma de células escamosas y la diferencia de carcinoma de células pequeñas fue estadísticamente significativa (P <0,05) .TTF-1, Syn, CgA y la expresión de CD56 fueron más frecuentes en adenocarcinoma, con sensibilidad y especificidad de 86.33 % y 93.44 %, 89.21 % y 98.36 %, 74.10 % y 100 %, 96.40 % y 96.72 %. La detección combinada de CK5 / 6, P63 y P40 fue más útil y específica en la diferenciación del carcinoma de células escamosas. CK7, TTF-1 y NapsinA fueron más útiles y específicos para diferenciar el adenocarcinoma de pulmón. El deterioro de CD56, TTF-1, Syn y CgA refleja la progresión del cáncer de pulmón de células pequeñas.

Treatment and prognostic analysis of patients with primary esophageal small-cell carcinoma / 中华肿瘤杂志

The study aimed to analyze the clinicopathological features, treatment, and prognosis factors of primary esophageal small-cell carcinoma (PESC). The clinical records and follow-up data of 100 patients with PESC were collected, and the clinicopathological features and treatments were examined. Log-rank test and Cox regression model were performed to identify the independent prognostic factors. Progressive dysphagia, weight loss, and abdominal pain were the most common initial symptoms in the 100 patients with PESC. The primary tumor site mainly occurred in the middle of the chest (51%, 51/100), and the ulcer type was the most common under gastroscope (31%, 31/100). One or more positive markers of epithelial origin were present in all of the enrolled patients. At the time of diagnosis, 80 cases had limited disease (LD) and 20 cases had extensive disease (ED). The 1-, 3-, and 5-year survival rates of PESC patients were 57.0%, 18.0%, and 11.0%, respectively, with a median survival time (MST) of 13.8 months. In all PESC patients, multivariate Cox regression analysis indicated that the significant prognostic factors included the lesion length (=2.661, <0.001), TNM staging (=1.464, =0.016), and treatment methods (=0.333, <0.001). Besides, in patients with LD, the lesion length (=2.638, =0.001) and treatment methods (=0.285, <0.001) were independent prognostic factors. The MST of patients in surgery + chemotherapy group (21.6 months) was longer than that of the surgery only group (8.3 months, =0.021), while patients in surgery+ chemotherapy+ radiotherapy group were also associated with a longer MST than the chemotherapy + radiotherapy group (31.0 months, 9.8 months, respectively; <0.001). PESC is a rare esophageal malignant tumor with poor prognosis. Our findings reveal that the lesion length, TNM staging, and treatment method are independent prognostic factors for PESC patients. Moreover, surgery-based comprehensive treatments may prolong the survival of patients with LD.

Small cell bladder cancer: should we consider prophylactic cranial irradiation?

ABSTRACT Purpose: To describe the clinical characteristics, treatment patterns, and outcomes in patients with small cell bladder cancer at our institution, including those who received prophylactic cranial irradiation (PCI) for the prevention of intracranial recurrence. Materials and Methods: Patients with small cell bladder cancer treated at a single institution between January 1990 and August 2015 were identified and analyzed retrospectively for demographics, tumor stage, treatment, and overall survival. Results: Of 44 patients diagnosed with small cell bladder cancer, 11 (25%) had metastatic disease at the time of presentation. Treatment included systemic chemotherapy (70%), radical surgery (59%), and local radiation (39%). Six patients (14%) received PCI. Median overall survival was 10 months (IQR 4 - 41). Patients with extensive disease had worse overall survival than those with organ confined disease (8 months vs. 36 months, respectively, p = 0.04). Among those who received PCI, 33% achieved 5 - year survival. Conclusion: Outcomes for patients with small cell bladder cancer remain poor. Further research is indicated to determine if PCI increases overall survival in small call bladder cancer patients, especially those with extensive disease who respond to chemotherapy.

Neuroendocrine cells of prostate cancer: biologic functions and molecular mechanisms / 亚洲男科学杂志(英文版)

Prostate cancer (PCa) is a major health risk for older men worldwide. Existing systemic therapies mostly target androgen receptor (AR). Although treatments are initially effective, the disease always recurs. A potential mechanism for the treatment failure is that PCa contains, in addition to the AR-positive luminal type tumor cells, a small component of neuroendocrine (NE) cells. The function of NE cells in PCa remains poorly understood, and one important characteristic of these cells is their lack of expression of AR and resistance to hormonal therapy. In addition, many patients develop the more aggressive small-cell neuroendocrine carcinoma (SCNC) after hormonal therapy. Although this clinical phenomenon of disease transformation from adenocarcinoma to SCNC is well established, the cell of origin for SCNC remains unclear. Recently, loss of function of Rb and TP53 and amplification and overexpression of MYCN and Aurora A kinase have been identified as important biomarkers and potential disease drivers. In this article, we systematically review the histology of normal prostate and prostate cancer including the main histologic types: adenocarcinoma and SCNC. We also review the findings from many studies using cellular and animal models as well as human specimens that attempt to understand the molecular mechanisms of treatment failure, disease progression, and tumor transformation from adenocarcinoma to SCNC.

Clinicopathologic features, treatment, prognosis and prognostic factors of neuroendocrine carcinoma of the endometrium: a retrospective analysis of 42 cases from the Kansai Clinical Oncology Group/Intergroup study in Japan / 부인종양

OBJECTIVE: We conducted a retrospective, multi-institutional, collaborative study to accumulate cases of neuroendocrine carcinoma of the endometrium, to clarify its clinicopathologic features, treatment, prognosis and prognostic factors to collate findings to establish future individualized treatment regimens. To our knowledge, this is the largest case study and the first study to statistically analyze the prognosis of this disease. METHODS: At medical institutions participating in the Kansai Clinical Oncology Group/Intergroup, cases diagnosed at a central pathologic review as neuroendocrine carcinoma of the endometrium between 1995 and 2014 were enrolled. We retrospectively analyzed the clinicopathologic features, treatment, prognosis and prognostic factors of this disease. RESULTS: A total of 65 cases were registered from 18 medical institutions in Japan. Of these, 42 (64.6%) cases were diagnosed as neuroendocrine carcinoma of the endometrium based on the central pathological review and thus included in the study. Advanced International Federation of Gynecology and Obstetrics stages (stage III and IV) and pure type small cell neuroendocrine carcinoma cases had a significantly worse prognosis. Upon multivariate analysis, only histologic subtypes and surgery were significant prognostic factors. Pure type cases had a significantly worse prognosis compared to mixed type cases and complete surgery cases had a significantly better prognosis compared to cases with no or incomplete surgery. CONCLUSION: Our findings suggest that complete surgery improves the prognosis of neuroendocrine carcinoma of the endometrium. Even among cases with advanced disease stages, if complete surgery is expected to be achieved, clinicians should consider curative surgery to improve the prognosis of neuroendocrine carcinoma of the endometrium.

Primary Gastric Small Cell Carcinoma (Presenting as Linitis Plastica) Diagnosed Using Endoscopic Ultrasound-Guided Biopsy: A Case Report

Small cell carcinomas are the most aggressive, highly malignant neuroendocrine tumors; among these, gastric small cell carcinoma (GSCC) is extremely rare. Here we report a case of a patient with primary GSCC, presenting as linitis plastic, who was diagnosed using endoscopic ultrasound (EUS)-guided biopsy. With undiagnosed linitis plastica, an 80-year-old woman was referred to our institution. Abdominal computed tomography revealed irregular wall thickening extending from the gastric body to the antrum. Endoscopy suspected to have Borrmann type IV advanced gastric cancer. EUS of the stomach showed diffuse submucosal thickening of the gastric wall, mainly the antrum. EUS-guided bite-on-bite biopsy confirmed the diagnosis of GSCC. In general, GSCC is difficult to diagnose and careful examination is necessary to determine the therapeutic strategy; however, EUS is particularly helpful in the differential diagnosis of a lesion presenting as linitis plastica.

Primary Gastric Small Cell Carcinoma: A Case Identified as a Large Subepithelial Tumor from Invisible State in 6 Months

Primary gastric small cell carcinoma (GSCC) is one of the gastroenteropancreatic neuroendocrine tumors. It is a rare cancer with a very aggressive behavior and a poor prognosis because of the high rate of metastases. It is usually found in far advanced stage. We experienced a case of GSCC which had developed into a large subepithelial tumor (SET) from invisible state in a short period. A 65-year-old man consulted our hospital because of early gastric cancer. He underwent endoscopic submucosal dissection for the early gastric cancer at high body posterior wall. After 6 months, the follow-up endoscopy showed a large newly developed SET-like lesion with central ulceration at the gastric cardia. Endoscopic biopsy revealed GSCC. Total gastrectomy was performed. One out of the 26 perigastric lymph nodes had a metastasis. He received 6 cycles of adjuvant chemotherapy with etoposide and cisplatin. He is still in good health 12 months after operation.

Carcinoma neuroendocrino primario de vagina. Revisión de literatura a propósito de un caso / Primary neuroendocrine carcinoma of the vagina. Literature review on the subject of a case

RESUMEN El carcinoma primario de vagina representa 1 a 2% de los cánceres ginecológicos, siendo la diferenciación histológica neuroendocrina de células pequeñas extremadamente infrecuente, sólo se han reportado 28 casos en la literatura, describiéndose en orden de frecuencia en cérvix, endometrio, ovario, vagina y vulva. Se observa con más frecuencia en mujeres postmenopáusicas. Se presenta el caso de paciente femenino, de 39 años de edad, quien acude a la consulta por presentar secreción genital serohemática, fétida, de 1 mes de evolución, evidenciándose al examen físico lesión exofítica, friable, renitente, de aproximadamente 4 cm de diámetro, en tercio superior y cara posterolateral izquierda de vagina, por lo que se realiza biopsia excisional de dicha lesión, siendo el diagnóstico anatomopatológico carcinoma neuroendocrino de células pequeñas, grado histológico: 3. A propósito de este caso, se realiza una revisión del tema, haciendo hincapié en la importancia de la exploración ginecológica exhaustiva que incluya tomas de citologías y colposcopias periódicas, tomando en cuenta la vagina y así, realizar diagnóstico precoz en vista que el riesgo de carcinoma en dicha zona es infrecuente, mejorando el pronóstico y sobrevida de las pacientes.

ABSTRACT The primary carcinoma of the vagina represents 1 to 2 % of gynecologic cancers, being the histological differentiation neuroendocrine of small cells extremely infrequent, only 28 cases have been reported in the literature, describing in order of frequency: in the cervix, endometrium, ovary, vagina and vulva. It is most commonly seen in postmenopausal women. We present the case of a female patient, 39 years old, who comes to medical consult due to serohematic, fetid, genital discharge of 1 month of evolution, evidencing at physical examination an exophytic lesion, friable, renitent, with a diameter of approximately 4 cm, in the upper third and posterolateral left side of the vagina, for which an excisional biopsy of said lesion is performed, being the anatomopathological diagnosis neuroendocrine carcinoma of small cells, histological grade: 3. A bibliography reviewed was made, emphasizing the importance of exhaustive gynecological exploration with periodic cytology and colposcopy examinations, including the vagina for early diagnosis in view of carcinoma risk in this area is uncommon, improving the prognosis and survival of patients.

Poorly Differentiated Neuroendocrine Carcinoma of the Eyelid

PURPOSE: To report a case of poorly differentiated neuroendocrine carcinoma of the eyelid. CASE SUMMARY: A 70-year-old male presented with a 5-month history of a right upper eyelid mass. The mass appeared as 1.2 × 1.2 cm on the right upper eyelid. A mass excision was performed under frozen section control. The tumor was completely excised with a safety margin clearance and an upper eyelid reconstruction was performed. Histopathological examination revealed a tumor composed of small atypical cells which showed a high nuclear/cytoplasm ratio, nuclear molding, and increased mitotic activity. Immunohistochemical examination revealed positive reactivity for Ki-67, synaptophysin, CD56, and negative reactivity for chromogranin, cytokeratin 20, and thyroid transcription factor-1. CONCLUSIONS: Primary neuroendocrine carcinoma of the eyelid is extremely rare, but the tumor has high malignancy and readily metastasizes. Poorly differentiated neuroendocrine carcinoma should be considered in the differential diagnosis of a rapidly growing eyelid mass.

Chemotherapy for Small Cell Carcinoma of Gallbladder: A Case Report / 대한췌담도학회지

Small cell carcinoma (SCC) of the gallbladder is a rare disease. It is an aggressive tumor that tends to metastasis early and is associated with poor prognosis. Median overall survival is reported to be approximately 13 months. Metastatic disease has a worse prognosis, and median overall survival is reported to be approximately 4 months. A 65-year-old male patient was diagnosed with the SCC of the gallbladder and was treated with cisplatin/etoposide chemotherapy followed by radiation therapy. Here, we describe the case of the SCC of the gallbladder who survived more than 3 years followed by the review of the literatures on this disease.

Small Cell Carcinoma arising from a mature Cystic Teratoma of the ovary: A case report / Philippine Journal of Obstetrics and Gynecology

@#Malignant transformation of a mature cystic teratoma (MCT) or dermoid cyst in the ovary occurs only 1 to 2% of cases of MCTs. Only 6 cases of small cell carcinoma arising from a MCT have been reported. The patient is a 36 year-old G2P2(2002) who presented with an enlarging abdominal mass and right lower quadrant pain. She was diagnosed with a dermoid cyst four years prior to admission, but no surgical intervention was done. On admission, ultrasound revealed multiple pelvo-abdominal masses consistent with dermoid cysts. The patient underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, peritoneal fluid cytology, bilateral pelvic lymph node dissection, excision of enlarged paraaortic lymph nodes and infracolic omentectomy. Histopathology revealed a small cell carcinoma arising from a MCT in the left ovary consistent with a Stage IIIA1ii tumor. She underwent chemotherapy with 4 cycles of Etoposide-Cisplatin and has no evidence of disease 3 months after treatment.

Carcinoma de células pequeñas de vejiga, a propósito de un caso / Carcinoma of bladder small cells: with regard to a case

Introducción: El carcinoma de células pequeñas de vejiga es una neoplasia poco frecuente que puede coexistir con un carcinoma urotelial. Ocurre principalmente en el sexo masculino en la séptima y octava décadas de vida. Macroscópicamente se observa como una masa sólida, polipoide y microscópicamente se conforma por células atípicas con núcleos hipercromáticos y una alta tasa mitótica. Caso: Paciente de 56 años, masculino, fumador que refiere que desde hace 6 meses presentó hematuria, con disuria y dificultad para orinar. Se realizó cistoscopía encontrándose lesión tumoral en vejiga por lo que se sometió a cistoprostatectomía radical. Discusión: El carcinoma vesical de células pequeñas es poco frecuente y puede coexistir con el carcinoma urotelial. El estudio anátomo patológico es fundamental para determinar el diagnóstico siendo necesarios marcadores de inmunohistoquímica como sinaptofisina, CD56, cromogranina y enolasa. La cirugía, quimioterapia y radiación se utilizan para dar un tratamiento multidisciplinario de la enfermedad.

Introduction: Small cell carcinoma of the bladder is a rare neoplasm, which can coexist many times with an urothelial carcinoma. It occurs mainly in males in the seventh and eighth decades of life. Macroscopically it is observed as a solid and polypoid mass and microscopically it is conformed by atypical cells with hyperchromatic nuclei and a high mitotic rate. Case: A 56-year-old man, smoker who has hematuria for six months, and dysuria and difficulty to urinate. In a cystocopy a bladder tumor is identified and a radical cistoprostectomy is performed. Discusion: Small cell vesical carcinoma is uncommon and may coexist with urothelial carcinoma. The anatomical pathological study is fundamental to determine the diagnosis, requiring immunohistochemical markers such as synaptophysin, CD56, chromogranin and enolase. Surgery, chemotherapy and radiation are used to provide a multidisciplinary treatment of the disease.

Small cell neuroendocrine carcinoma of the nasopharynx: a rare case report

Small cell neuroendocrine carcinoma rarely appears primarily in the head and neck and exhibits aggressive behavior with a poor prognosis. The pathologist has a significant role in the diagnosis, and a consensual treatment still does not exist. The authors report the case of a middle-aged male patient who presented repeated episodes of massive epistaxis. The diagnostic work-up disclosed the diagnosis of small cell neuroendocrine carcinoma of the nasopharynx. The patient was treated with chemotherapy followed by radiotherapy. Imaging examinations performed after the end of treatment showed apparent complete remission of the disease. The patient was kept under active surveillance with no signs of local relapse or distant metastasis after 4 years of follow-up.

Mandible metastasis of small cell lung cancer mimicking a residual cyst

Small cell lung carcinoma (SCLC) is an uncommon tumor characterized by an aggressive behavior with early metastasis, usually to the contralateral lung, liver, brain, and bones. There are only five cases of this particular tumor metastasizing to the oral cavity described in the English literature. We present the case of metastatic SCLC in the mandible with radiographic findings resembling a residual cyst. A 66-year-old man with previous diagnosis and treatment for a SCLC was referred to the Stomatology Department with a history of persistent pain in the mandible 1 year after the inferior right pre-molar tooth extraction. The radiographic exam showed a well-delimited radiolucent area on that extracted tooth's region resembling a residual cyst. Biopsy was performed yielding the diagnosis of metastatic SCLC. The patient was referred to the clinical oncologist for chemotherapy. Although uncommon, this tumor should be included in the differential diagnosis of jawbone lesions, particularly when the patient presents a previous diagnosis of SCLC.

Lung Cancer Risk and Residential Exposure to Air Pollution: A Korean Population-Based Case-Control Study

PURPOSE: To investigate the association between long-term exposure to ambient air pollution and lung cancer incidence in Koreans. MATERIALS AND METHODS: This was a population-based case-control study covering 908 lung cancer patients and 908 controls selected from a random sample of people within each Korean province and matched according to age, sex, and smoking status. We developed land-use regression models to estimate annual residential exposure to particulate matter (PM₁₀) and nitrogen dioxide (NO₂) over a 20-year exposure period. Logistic regression was used to estimate odds ratios (ORs) and their corresponding 95% confidence intervals (CI). RESULTS: Increases in lung cancer incidence (expressed as adjusted OR) were 1.09 (95% CI: 0.96−1.23) with a ten-unit increase in PM₁₀ (µg/m³) and 1.10 (95% CI: 1.00−1.22) with a ten-unit increase in NO₂ (ppb). Tendencies for stronger associations between air pollution and lung cancer incidence were noted among never smokers, among those with low fruit consumption, and among those with a higher education level. Air pollution was more strongly associated with squamous cell and small cell carcinomas than with adenocarcinoma of the lung. CONCLUSION: This study provides evidence that PM₁₀ and NO₂ contribute to lung cancer incidence in Korea.