Primary cutaneous ganglioneuroma: anatomico-clinical study of 4 cases with focus on Merkel cells.

Cutaneous ganglioneuromas (CGNs) are exceptional. We aim to describe the anatomico-clinical profile of primary CGN and report 4 cases. Patients were 2 men and 2 women aged 53 to 76 years, who had flesh-colored nodules on the back, associated with adjacent keratotic changes, that is, epidermal nevus (1 case) or seborrheic keratosis (3 cases). Histopathology showed ganglion cells within a proliferation of Schwann cells. The epidermis was acanthotic, associated with sebaceous induction in 2 cases, with follicular hyperplasia as in fibroepithelial tumors (1 case) or with tricholemmoma (2 cases). Cytokeratin-20 immunostaining showed Merkel cells in the epidermis. A higher density of Merkel cells was observed in BerEP4+ follicular structures. Along with 16 published cases, our study indicates that a nodule associated with seborrheic keratosis on the back may represent a CGN, a complex mesenchymal and epidermal/follicular lesion of neuroectodermal lineage, associating neuronal proliferation and Merkel cell hyperplasia with follicular induction.

[Gastro-intestinal neuroectodermal tumor (GNET): A case report of a small intestine tumor with hepatic metastases]. / Tumeur neuroectodermique gastro-intestinale (GNET) : à propos d'un cas de tumeur du grêle avec métastases hépatiques.

The gastro-intestinal neuroectodermal tumor (GNET) is a rare sarcoma of the digestive tract, which was recently recognised. The knowledge of the morphological, immunohistochemical and molecular diagnostic criteria is necessary to not mistake it for the metastasis of a melanoma or for another sarcoma of the digestive tract as the gastro-intestinal clear cells sarcoma or the malignant peripheral nervous system tumor (MPNST). We report the case of a 41-year-old patient with a GNET of the small intestine with hepatic metastasis. The histological examination showed a diffuse proliferation of epithelioid cells, which only express PS100. The presence EWSR1-ATF1 gene fusions with any melanocytic differentiation leads to the diagnosis of GNET.

[Colonic ulcers associated with taking Kayexalate(®) (sodium polystyrene sulfonate): about two cases]. / Ulcérations coliques associées à la prise de Kayexalate(®) (polystyrène sulfonate de sodium) : à propos de deux observations.

We report two cases of patients with chronic renal failure showing rectal bleeding due to digestive ulcers, associated with Kayexalate(®) alone. Kayexalate(®) crystals correspond to a typical histological picture and it is important to know how to identify them in order to discuss a possible pathogenicity.

[Hemophagocytic lymphohistiocytosis associated with a lymphohistiocytic pattern anaplastic large cell lymphoma: a case report]. / Syndrome d'activation macrophagique révélant un lymphome anaplasique à grandes cellules de variante lymphohistiocytaire : à propos d'un cas.

We report the case of a 16-year-old girl with an anaplastic large cell lymphoma of lymphohistiocytic pattern revealed by a hemophagocytic syndrome. Histologically, the lymphomatous population was concealed by clusters of histiocytes. Immunohistochemical study allowed the diagnosis. The combination of these two entities is rarely described and may be a source of delay in diagnosis of a life-threatening condition.

Familial acampomelic form of campomelic dysplasia caused by a 960 kb deletion upstream of SOX9.

Campomelic dysplasia (CD) is a rare autosomal dominant osteochondrodysplasia with or without XY disorders of sexual development (DSD). Campomelia is absent in about 10% of the cases, referred to as the acampomelic form of CD (ACD). Most CDs are caused by mutations within the SOX9 coding region. Several CD patients with balanced chromosome rearrangements involving the 17q24 region have been reported suggesting the presence of cis-regulatory elements upstream and/or downstream of the gene. Deletions upstream of SOX9 represent a third mechanism of mutation. To date, a 1.5 Mb de novo deletion in the SOX9 upstream region has been identified in a single 46,XY patient with ACD and DSD. We report here for the first time on a familial ACD caused by an inherited deletion mapping upstream of the SOX9 gene. Using high-density oligoarray comparative genomic hybridization (CGH), we showed that the size of the deletion was 960 kb in the XY-DSD child and her mother, both affected. The deletion lying from 517 kb to 1.477 Mb upstream of SOX9 remove several highly conserved elements and reduce the minimum critical size and therefore the number of highly conserved sequence elements responsible for ACD.