A convolutional neural network-based system to classify patients using FDG PET/CT examinations.

BACKGROUND: As the number of PET/CT scanners increases and FDG PET/CT becomes a common imaging modality for oncology, the demands for automated detection systems on artificial intelligence (AI) to prevent human oversight and misdiagnosis are rapidly growing. We aimed to develop a convolutional neural network (CNN)-based system that can classify whole-body FDG PET as 1) benign, 2) malignant or 3) equivocal. METHODS: This retrospective study investigated 3485 sequential patients with malignant or suspected malignant disease, who underwent whole-body FDG PET/CT at our institute. All the cases were classified into the 3 categories by a nuclear medicine physician. A residual network (ResNet)-based CNN architecture was built for classifying patients into the 3 categories. In addition, we performed a region-based analysis of CNN (head-and-neck, chest, abdomen, and pelvic region). RESULTS: There were 1280 (37%), 1450 (42%), and 755 (22%) patients classified as benign, malignant and equivocal, respectively. In the patient-based analysis, CNN predicted benign, malignant and equivocal images with 99.4, 99.4, and 87.5% accuracy, respectively. In region-based analysis, the prediction was correct with the probability of 97.3% (head-and-neck), 96.6% (chest), 92.8% (abdomen) and 99.6% (pelvic region), respectively. CONCLUSION: The CNN-based system reliably classified FDG PET images into 3 categories, indicating that it could be helpful for physicians as a double-checking system to prevent oversight and misdiagnosis.

Desmoplastic small round cell tumor: Diagnostic dilemma and uncertain prognosis: Report of few cases.

Desmoplastic small round cell tumor (DSRCT) is rare and highly malignant neoplasm. DSRCT affects usually young males but can occur in adults also. Intra-abdominal pelvic region is the preferred site. Though confirmed by histology, immunohistochemistry (IHC) plays a key role in diagnosis. IHC profile is characteristic, it shows simultaneous expression of epithelial (epithelial membrane antigen (EMA) and cytokeratin (CK)), muscular (desmin), and neural (neuron-specific enolase) markers. Many cases of DSRCT are diagnosed as poorly differentiated carcinoma due to lack of proper panel of IHC. It is difficult to predict if there has been a true increase in incidence. Prognosis is uncertain in such an aggressive neoplasm as chemotherapy (CT) or radiotherapy (RT) shows various outcomes. Here in; we report four cases, all of which showed diagnostic dilemma and uncertain prognosis.

Extragonadal teratomas of the adult abdomen and pelvis: a pictorial review.

Teratomas comprise a spectrum of tumours that have striking imaging appearances and are commonly considered when evaluating a mass in the female pelvis. A subgroup of these tumours located in an extragonadal abdominopelvic location, in contrast, are extremely rare and can affect both sexes. Extragonadal teratomas can occur at all ages, are particularly unusual in adults and can cause confusion in the differential diagnosis, especially in children. Familiarity with the imaging features of the spectrum of teratomas within the abdominal cavity is therefore of great importance, as radiological diagnosis can guide treatment, prevent delays in diagnosis and avoid sequelae. This article summarizes the radiological appearances of these rare extragonadal tumours in adults in relation to their pathology, malignant potential, location and behaviour. Although uncommon, teratomas should be considered in the differential diagnosis of extragonadal abdominal masses, particularly in young adults.

Role of diffusion-weighted imaging in differentiating benign and malignant pediatric abdominal tumors.

BACKGROUND: Solid malignant tumors are more highly cellular than benign lesions and hence have a restricted diffusion of water molecules. OBJECTIVE: To evaluate whether diffusion-weighted MR imaging (DWI) can differentiate between benign and malignant pediatric abdominal tumors. MATERIALS AND METHODS: We retrospectively analyzed DWI scans of 68 consecutive children with 39 benign and 34 malignant abdominal masses. To calculate the apparent diffusion coefficient (ADC) maps and ADC values, we used 1.5-T sequences at TR/TE/b-value of 5,250-7,500/54-64/b = 0, 500 and 3-T sequences at 3,500-4,000/66-73/b = 0, 500, 800. ADC values were compared between benign and malignant and between data derived at 1.5 tesla (T) and at 3 tesla magnetic field strength, using the Mann-Whitney-Wilcoxon test, ANOVA and a receiver operating curve (ROC) analysis. RESULTS: There was no significant difference in ADC values obtained at 1.5 T and 3 T (P = 0.962). Mean ADC values (× 10(-3) mm(2)/s) were 1.07 for solid malignant tumors, 1.6 for solid benign tumors, 2.9 for necrotic portions of malignant tumors and 3.1 for cystic benign lesions. The differences between malignant and benign solid tumors were statistically significant (P = 0.000025). ROC analysis revealed an optimal cut-off ADC value for differentiating malignant and benign solid tumors as 1.29 with excellent inter-observer reliability (alpha score 0.88). CONCLUSION: DWI scans and ADC values can contribute to distinguishing between benign and malignant pediatric abdominal tumors.

Epithelioid inflammatory myofibroblastic sarcoma: An aggressive intra-abdominal variant of inflammatory myofibroblastic tumor with nuclear membrane or perinuclear ALK.

Inflammatory myofibroblastic tumor (IMT) is a mesenchymal neoplasm of intermediate biological potential, which may recur and rarely metastasize. Pathologic features do not correlate well with behavior. Approximately 50% of conventional IMTs harbor ALK gene rearrangement and overexpress ALK, most showing diffuse cytoplasmic staining. Rare IMTs with a distinct nuclear membrane or perinuclear pattern of ALK staining and epithelioid or round cell morphology have been reported. These cases pursued an aggressive clinical course, suggesting that such patterns may predict malignant behavior. We describe 11 cases of IMT with epithelioid morphology and a nuclear membrane or perinuclear pattern of immunostaining for ALK. Ten patients were male and 1 was female, ranging from 7 months to 63 years in age (median, 39 y). All tumors were intra-abdominal; most arose in the mesentery or omentum, measuring 8 to 26 cm (median, 15 cm). Six tumors were multifocal at presentation. The tumors were composed predominantly of sheets of round-to-epithelioid cells with vesicular nuclei, large nucleoli, and amphophilic-to-eosinophilic cytoplasm. In all cases, a minor spindle cell component was present. Nine tumors had abundant myxoid stroma. In 7 cases neutrophils were prominent and in 3 cases lymphocytes were prominent. Plasma cells were often absent. Median mitotic rate was 4/10 HPF; 6 tumors had necrosis. By immunohistochemistry, all tumors were positive for ALK, 9 tumors showing a nuclear membrane staining pattern and 2 tumors showing a cytoplasmic pattern with perinuclear accentuation. Other positive markers were desmin (10 of 11), focal smooth muscle actin (4 of 8), and CD30 (8 of 8). All tumors were negative for MYF4, caldesmon, keratins, EMA, and S-100. Fluorescence in situ hybridization was positive for ALK gene rearrangement in 9 cases, and in 3 cases tested, a RANBP2-ALK fusion was detected by reverse transcription polymerase chain reaction. Ten patients underwent surgical resection; 1 patient was inoperable. Follow-up was available for 8 patients and ranged from 3 to 40 months (median, 13 mo). All patients experienced rapid local recurrences; 4 patients had multiple recurrences. Eight patients were treated with postoperative chemotherapy; 2 patients received additional radiotherapy. Two patients also developed metastases (both patients developed metastases to the liver; 1 patient developed metastases to the lung and lymph nodes as well). Thus far, 5 patients died of disease, 2 patients are alive with disease, and 1 patient, treated with an experimental ALK inhibitor, has no evidence of disease. In summary, the epithelioid variant of IMT with nuclear membrane or perinuclear ALK is a distinctive intra-abdominal sarcoma with a predilection for male patients. Unlike conventional IMT, abundant myxoid stroma and prominent neutrophils are common. These tumors pursue an aggressive course with rapid local recurrences and are frequently fatal. We propose the designation "epithelioid inflammatory myofibroblastic sarcoma" to convey both the malignant behavior of these tumors and their close relationship with IMT.

Early and reliable diagnosis of non-Hodgkin lymphoma in childhood and adolescence: contribution of cytomorphology and flow cytometric immunophenotyping.

Non-Hodgkin lymphoma (NHL) represents one of the most rapidly growing malignancies in childhood and adolescence. About 80% of patients now are cured with adequate treatment. Serious complications at presentation due to tumor lysis syndrome or local tumor effects are commonly observed. Thus, a rapid diagnosis with the least invasive procedure enabling the initiation of early and specific therapy is necessary to diminish early fatality or persistent impairment. In 56 centrally registered patients with NHL, cytomorphologic analyses (FAB criteria) of May-Grünwald-Giemsa-stained touch imprints or malignant effusions and flow cytometric immunophenotyping (EGIL criteria) of fresh cell suspensions with a standardized panel of monoclonal antibodies were performed. The authors identified 23 patients with Burkitt lymphoma by the combination of FAB L3 morphology and a mature B-cell phenotype and 22 patients with lymphoblastic lymphoma by FAB L1/L2 morphology and a T-/B-cell precursor phenotype. They also found 11 patients with large cell lymphomas, 3 of them with anaplastic large cell lymphoma (T-cell phenotype; NPM/ALK-positive). In the remaining 8 patients diffuse large B-cell lymphoma was suspected by the combined use of cytologic and immunophenotypic findings (mature B-cell phenotype). In all cases with available solid tumor material (n = 42/56) the preliminary diagnosis was confirmed by histopathology. Burkitt lymphoma, lymphoblastic lymphoma, and, in a few cases, some large cell lymphomas could be classified reliably by cytomorphology and immunophenotyping of freshly obtained tumor cell material, enabling an early start of specific lymphoma treatment.

Lipoblastoma: better termed infantile lipoma?

Lipoblastoma is a rare adipose tumor occurring exclusively in childhood. There have been no reports of metastases, making the designation "blastoma" confusing, since this term is usually reserved for malignant tumors. Two recent cases treated at our institution confirm its benign nature. In addition, a review of the literature supports the idea that the tumor may more accurately be described as an "infantile lipoma". Infantile lipoma better reflects many of the tumor's characteristics such as, its early occurrence, it's ability to mature into a simple lipoma, it's cellular composition of mainly mature adipocytes, and its benign course. Although lipoblastoma is an uncommonly encountered tumor, making an effort to change its name to infantile lipoma will result in a more a accurate term that will facilitate treatment.

Laparoscopy in 533 patients with abdominal malignancy.

BACKGROUND: Laparoscopy in patients with intra-abdominal malignancy remains controversial. This study evaluates the incidence of tumor recurrence at the port site after laparoscopy in patients with intra-abdominal malignancy. METHODS: The medical records of all patients with nongynecologic malignancies who underwent laparoscopic procedures between May 1, 1990, and June 30, 1996, at the University of Texas M.D. Anderson Cancer Center were reviewed. Data on extent of tumor, histologic findings, primary location, procedures performed, and complications were recorded. RESULTS: During this time, 533 patients with known intra-abdominal malignancies underwent laparoscopy. Mean follow-up time was 13.2 +/- 0.5 months (range 1 to 71 months; median 10.6 months). Four recurrences at the port site were identified (0.8%). Three of these patients had advanced intra-abdominal disease at the time of laparoscopy; 1 patient without advanced disease at the time of laparoscopy had a recurrence at the port site as the only site of recurrent disease (0.19%). The incidence of port site recurrences among patients with advanced intra-abdominal disease at the time of laparoscopy (3/71) was significantly greater than the risk of development of a recurrence at the port site among patients without advanced intra-abdominal disease at the time of laparoscopy (1/462; P < .0003, by chi-square analysis). CONCLUSION: Recurrence at the port site is very rare. When implantation at the port site does occur, it is most commonly associated with advanced intra-abdominal disease.

Efficacy of ultrasonic mass survey for abdominal cancer.

From August 1983 through March 1995, 204,099 people received ultrasonic mass survey of the abdomen for the first time. Among these examinees, 631 (0.31%) malignant neoplasm cases, such as 201 hepatocellular carcinoma (HCC), 81 gallbladder (GB) cancer, 57 pancreatic cancer, and 169 renal cell carcinoma (RCC), were detected. Three hundred seventy six out of 590 cases (64%), excluding chronic leukemia cases and metastatic liver cancer cases, were surgically resected. The resection rate of HCC, GB cancer, pancreatic cancer, and RCC were 25%, 88%, 49%, and 99%, respectively. The cumulative survival rate of the 376 resected cases was 79.5% at 10 years. The cumulative survival rates of resected cases of HCC, GB cancer, pancreatic cancer and cumulative survival rates of resected cases of HCC, GB cancer, pancreatic cancer and RCC were 34% at ten years, 83% at 10 years, 49% at 7 years, and 99% at 10 years, respectively. Ultrasonic mass survey is dramatically useful for early detection of various kinds of abdominal cancers, especially RCC and GB cancer. From now on, many earlier abdominal cancers will be found by establishing and promoting ultrasonic mass survey systems.

Insular carcinoma: a distinct de novo entity among follicular carcinomas of the thyroid gland.

We reclassified 720 nonmedullary invasive thyroid carcinomas diagnosed and treated between 1975 and 1993. Twenty-seven cases met the criteria of insular carcinoma and 29 cases those of widely invasive follicular carcinoma. Comparison of these histotypes with respect to pathologic stage and overall, relative, and visceral metastasis-free survival showed a significant association between histotype and pT and pN categories. In particular, pT4 (p < 0.001) and pN1 (p < 0.001) categories were more frequent in the insular carcinoma histotype. By contrast, no significant differences in overall, relative, or visceral metastasis-free survival were observed between insular carcinoma and widely invasive follicular carcinoma. Molecular analysis by polymerase chain reaction-single-strand conformation polymorphism demonstrated RAS gene family point mutations in five of eight cases analyzed in each of the two histotypes, with a high proportion of CAA-->AAA transversion at codon 61 of the N-RAS gene in insular carcinoma. These findings suggest that insular carcinoma represents a de novo entity distinct from widely invasive follicular carcinoma, that widely invasive follicular carcinoma has biologic characteristics more consistent with poorly differentiated than well-differentiated carcinomas, and that both insular carcinoma and widely invasive follicular carcinoma share similar molecular alterations.

Endometrial stromal sarcoma with focal smooth muscle differentiation: recurrence after 17 years: a follow-up report with discussion of the nomenclature.

In 1977, a case report was published describing a 28-year-old women with an endometrial stromal tumor that showed foci of myogenic differentiation. The term "stromomyoma" was introduced to encompass both this type of neoplasm as well as "uterine neoplasms resembling ovarian sex-cord tumors" (UTROSCTs). More than 17 years later, the tumor recurred, involving the right ovary, sigmoid colon, small bowel, abdominal wall and omentum. The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed. Applying the recent classification and diagnostic criteria of endometrial mesenchymal neoplasms, we have concluded that this tumor was a low-grade endometrial stromal sarcoma (LGSS). The formerly proposed term "stromomyoma" implies a benign tumor, in contrast to the obviously malignant nature of this particular tumor. Focal myogenic differentiation of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarcomas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.

Masas abdominopelvianas gigantes: diagnóstico diferencial por tomografía axial computada / Giant abdominopelvian masses: differential diagnosis by CT

Entre el 1 de enero de 1992 y el 31 de diciembre de 1993, se realizaron 4.586 tomografías abdóminopelvianas, de las cuales 142 (3,1 por ciento) presentaron masas gigantes (mayores de 10 cm). Las masas gigantes se presentaron con mayor frecuencia entre la sexta y séptima década de la vida. Del total de pacientes, 81 fueron de sexo femenino (57,04 por ciento) y 61 de sexo masculino (42,96 por ciento). Los signos y síntomas que acompañaron a cada paciente fueron muy variados como así también la localización de dichas masas. La TC tuvo una sensibilidad del 100 por ciento para confirmar y diagnosticar la presencia de masas gigantes. El análisis semiológico de estas masas por TC, nos ha permitido determinar el órgano comprometido en un 97,88 por ciento; caracterizar el contenido y arquitectura del tumor en el 100 por ciento de los casos y evocar la naturaleza de las lesiones, refiriéndose al carácter benigno y maligno de las mismas en el 92,25 por ciento

Masas abdominopelvianas gigantes: diagnóstico diferencial por tomografía axial computada / Giant abdominopelvian masses: differential diagnosis by CT

Entre el 1 de enero de 1992 y el 31 de diciembre de 1993, se realizaron 4.586 tomografías abdóminopelvianas, de las cuales 142 (3,1 por ciento) presentaron masas gigantes (mayores de 10 cm). Las masas gigantes se presentaron con mayor frecuencia entre la sexta y séptima década de la vida. Del total de pacientes, 81 fueron de sexo femenino (57,04 por ciento) y 61 de sexo masculino (42,96 por ciento). Los signos y síntomas que acompañaron a cada paciente fueron muy variados como así también la localización de dichas masas. La TC tuvo una sensibilidad del 100 por ciento para confirmar y diagnosticar la presencia de masas gigantes. El análisis semiológico de estas masas por TC, nos ha permitido determinar el órgano comprometido en un 97,88 por ciento; caracterizar el contenido y arquitectura del tumor en el 100 por ciento de los casos y evocar la naturaleza de las lesiones, refiriéndose al carácter benigno y maligno de las mismas en el 92,25 por ciento (AU)

[Non-Hodgkin's lymphomas located in the abdomen in children]. / Nekhodzhkinskie limfomy s abdominal'noi lokalizatsiei u detei.

Long-term results of treatment of 126 cases of abdominal non-Hodgkin's lymphomas under 14 years are discussed. Survival doubled (from 24 to 49%) on application of modern methods of complex treatment. Such factors as stage, general symptoms, biologic activity and localization within the abdominal cavity at presentation were found to be of the highest prognostic value.