Synovial Sarcoma of the Gastrointestinal Tract.

We report the clinicopathologic and immunohistochemical features of 18 cases of confirmed primary synovial sarcoma of the gastrointestinal tract. The neoplasms arose in 10 women and 8 men ranging in age from 23 to 81 years (mean: 50; median: 57.5 years). The tumors for which size was known ranged from 1.8 to 15.0 cm (mean: 5.2; median: 5.1 cm). Microscopically, 14 synovial sarcomas were of the monophasic type, 2 were biphasic, and 2 were poorly differentiated. Immunohistochemical analysis of 4 cases showed strong, diffuse staining for SS18::SSX (4/4 cases). Pancytokeratin and EMA immunohistochemistry were performed on 13 and 9 tumors, respectively, and each showed patchy-to-diffuse staining. By reverse-transcription PCR, 3 cases were positive for the SS18::SSX1, and 2 cases were positive for the SS18::SSX2 gene fusion. Six cases contained an SS18 gene rearrangement by fluorescence in situ hybridization, and next-generation sequencing identified an SS18::SSX2 gene fusion in one case. Clinical follow-up information was available for 9 patients (4 months to 4.6 years; mean, 2.8 y; median: 29 months), and one patient had a recent diagnosis. Three patients died of disease within 41 to 72 months (mean, 56 months) of their diagnosis. Five patients were alive without evidence of disease 4 to 52 months (mean, 17.6 months) after surgery; of whom 1 of the patients received additional chemotherapy treatment after surgery because of recurrence of the disease. A single patient was alive with intraabdominal recurrence 13 months after surgery. We conclude that synovial sarcoma of the gastrointestinal tract is an aggressive tumor, similar to its soft tissue counterpart, with adverse patient outcomes. It is important to distinguish it from morphologically similar gastrointestinal tract lesions that may have different treatment regimens and prognoses.

Stromal and Epithelial Architectural Alterations Mimicking Invasion (Pseudoinvasion) in Noninvasive Papillary Urothelial Carcinoma.

CONTEXT.­: Retraction artifact, paradoxic maturation/differentiation, desmoplasia, and complex irregular growth are morphologic criteria of invasion in urothelial carcinoma. OBJECTIVE.­: To describe changes mimicking invasion in noninvasive papillary urothelial carcinoma (NPUC). DESIGN.­: We reviewed 159 consecutive in-house patients with NPUC for either the presence of pseudoinvasion (irregular carcinoma nests within dense hyalinized stroma in the absence of other criteria of invasion) or precursor findings (stromal hyalinization not yet associated with epithelial architectural alteration). We assessed the correlation of these findings with age, sex, evidence of peripheral vascular disease, tumor grade, tumor infarction, and tumor size. We then followed up the patients clinically for tumor recurrence or progression. RESULTS.­: We identified 233 separate NPUCs (136 high grade and 97 low grade) in 125 men and 34 women. Of the 233 tumors, 26 (11.2%) had pseudoinvasion and 24 of 233 tumors (10.3%) had precursor findings. Except for complex irregular growth, no other criteria for invasion were seen. Pseudoinvasion and precursor findings were more common in men (47 of 183 [26%] versus 3 of 50 [6%]; P = .003), larger tumors (mean size, 2.6 versus 1.2 cm; P < .001), and tumors with infarction (33 of 50 [66%] versus 29 of 183 [15.8%]; P < .001). In multivariable analysis, tumor size (odds ratio, 1.49; P =.006), male sex (odds ratio, 6.48; P = .007), and the presence of infarction (odds ratio, 6.59; P < .001) were significant variables. Recurrence rates did not differ between patients with and without pseudoinvasion (31% [5 of 16] versus 42% [45 of 107], respectively; P = .41). None of the tumors with pseudoinvasion progressed to invasive carcinoma. CONCLUSIONS.­: Given the correlation with size and presence of infarcted papillae, we suggest the possibility of tumor ischemia/infarction as a plausible etiology of pseudoinvasion. Awareness of this phenomenon is important for the accurate diagnosis of invasion in papillary urothelial carcinoma.

Severe type-B lactic acidosis in a patient with bilateral renal Burkitt's lymphoma.

INTRODUCTION: Lactic acidosis (LA) can be categorized as type A, which occurs in the presence of tissue hypoxia, or type B, occurring in the absence of tissue hypoxia. Hematologic malignancies are an uncommon cause of type B LA. CASE PRESENTATION: A 63-year-old man, HIV-negative, with a history of diabetes mellitus, hypothyroidism, and non-alcoholic fatty liver disease (NAFLD), presented to the ED complaining of acute-on-chronic lumbar pain, and was found to have high serum anion gap (AG) LA. The rest of chemistry and infectious workup was within normal limits. Despite bicarbonate therapy and fluid resuscitation, the patient remained with persistent AG metabolic acidosis and increasing lactic acid up to 14.5 mmol/L. An abdominal computerized tomography (CT) revealed multiple bilateral enhancing lesions in the kidneys, as well as gastric wall thickening. Upper gastrointestinal endoscopy with biopsy showed a high-grade Burkitt's lymphoma. Further staging showed bone marrow involvement and extensive abdominal adenopathy. After two cycles of inpatient chemotherapy with dose-adjusted EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin and rituximab), the patient developed multifocal pneumonia complicated by respiratory failure. Following a prolonged ICU stay, after discussion with the family members, a decision of withdrawal of life-sustaining therapy was reached. CONCLUSION: Persistent LA, without identifiable causes of tissue hypoxia, should prompt clinicians to suspect non-hypoxic etiologies, including occult high-grade malignancies. Hematological malignancies constitute an extremely rare cause of type-B LA, carrying a poor prognosis.

Application of a novel method of double APAAP staining with subsequent quantitative image analysis to the examination of integrin expression in undifferentiated-type gastric carcinomas.

In undifferentiated-type gastric carcinoma (UGC), recognition of cancer cells is not easy, which has hampered its precise phenotypic analysis. To examine alterations of the integrin phenotype during the progression of UGC, we used double alkaline phosphatase anti-alkaline phosphatase staining and computer-aided image analyses for the expression of alpha1, alpha2, alpha3, alpha5, alpha6, alphaV, beta1, and beta4 integrin subunits and alphaVbeta3, alphaVbeta5, and alphaVbeta6 integrins in cytokeratin-positive cells in the mucosal, the submucosal, and the deeper parts of 10 early and 17 advanced UGCs, their non-neoplastic counterparts, and 9 lymph node (LN) metastases. We revealed declining expression of epithelial integrin subunits (alpha2, alpha3, alpha6, beta4) and increasing expression of mesenchymal integrin subunits (alpha1, alpha5) as the tumor invaded deeper, reflecting gradual epithelial-to-mesenchymal transition of the integrin phenotype during tumor invasion. Enhanced expression of the alphaV integrin subunit and alphaVbeta3 and alphaVbeta5 integrins correlated with tumor invasion, and that of alphaVbeta6 integrins with LN metastasis. Our results have demonstrated that the method we introduced is suitable for analysis of dynamic alterations of the integrin repertoire in UGC progression.