Clinical and Histopathological Features of an Italian Monocentric Series of Primary Small Bowel T-Cell Lymphomas.

The gastrointestinal (GI) tract is the most common extranodal site of occurrence of non-Hodgkin lymphomas. Most GI lymphomas are of B-cell lineage, while T-cell lymphomas are less frequent. The aim of our retrospective study was to depict the clinical-pathological profile of a series of patients affected by intestinal T-cell lymphomas (ITCL) and possibly define hallmarks of these neoplasms. A total of 28 patients were included: 17 enteropathy-associated T-cell lymphomas (EATL), 5 monomorphic epitheliotropic T-cell lymphomas (MEITL), 3 indolent T-cell lymphoproliferative disorders of the gastrointestinal tract (ITCLDGT), and 3 intestinal T-cell lymphomas not otherwise specified (ITCL-NOS). Celiac disease (CD) was diagnosed in around 70% of cases. Diagnosis of EATL showed a significant correlation with CD30 expression, whereas MEITL with angiotropism and CD56 positivity. ITCLDGT cases showed plasma cells infiltration. Peripheral lymphocytosis, the absence of a previous diagnosis of CD, an advanced Lugano clinical stage, and the histological subtype ITCL-NOS were significantly associated with worse survival at multivariate analysis. Our findings about the epidemiological, clinical, and histopathological features of ITCL were in line with the current knowledge. Reliable prognostic tools for these neoplasms are still lacking but according to our results lymphocytosis, diagnosis of CD, Lugano clinical stage, and histological subtype should be considered for patient stratification.

A monolateral pigmented lesion of the nipple.

Pigmented mammary Paget's disease is a very rare variant of mammary Paget's disease linked to an underlying carcinoma in almost all cases. We present the case of a 62-year-old female patient who came to our attention for the evaluation of a monolateral asymptomatic pigmented lesion of the right nipple, which turned out to be a pigmented mammary Paget's disease unassociated to an underlying malignancy - an extremely rare entity only anecdotally reported in literature. The two main peculiarities of our patient's lesion, the importance of immunohistochemistry in the differential diagnosis and the theories on its pathogenesis are discussed. Further studies are necessary to establish the best treatment options. Click here for the corresponding questions to this CME article.

SIMPSON-GOLABI-BEHMEL syndrome type 1: How placental immunohistochemistry can rapidly Predict the diagnosis.

INTRODUCTION: Glypican-3 (GPC3) is an oncofetal protein involved in cellular signaling, strongly expressed in the placenta, absent or diminished in postnatal life, but often increased in human malignancies. Germline loss-of-function variants of GPC3 gene are associated with Simpson-Golabi-Behmel syndrome type 1 (SGBS1), a rare recessive X-linked overgrowth disease characterized by typical facial features, congenital abnormalities, and an increased risk of developing childhood cancers. METHODS: A clinical suspicion of SGBS1 was postulated for a newborn with prenatal history of overgrowth and polyhydramnios, presenting with neonatal weight and length >99th percentile, coarse facies, iris and retinal coloboma, supernumerary nipples, and splenomegaly. While waiting for whole-genome sequencing (WGS) results, we investigated placental GPC3 immunohistochemical expression in the proband, in three additional cases of SGBS1, and disorders commonly associated with fetal macrosomia and/or placentomegaly. RESULTS: WGS in the proband identified a likely pathogenic maternally inherited missense variant in GPC3: c.1645A > G, (p.Ile549Val), and GPC3 immunohistochemistry demonstrated full-thickness loss of stain of the placental parenchyma. The same pattern ("null") was also present in the placentas of three additional cases of SGBS1, but not in those of unaffected controls. DISCUSSION: Immunohistochemical expression of GPC3 in the placenta is highly reproducible. Our findings showed that a "null pattern" of staining is predictive of SGBS1 and represents a valuable aid in the differential diagnosis of fetal macrosomias, allowing targeted genetic testing and earlier diagnosis.