Neuroblastoma‐like schwannoma (NLS) is a rare variant of a common tumor. The aim of this study is to discuss, through a literature review, the differential diagnoses of NLS while emphasizing the importance of ancillary studies. So far, 24 cases have been reported. We describe an additional case in a 64‐year‐old woman who had a 3‐cm subcutaneous tumor on her flank. The histological examination showed an encapsulated neoplasm. Most of the tumor was made of giant rosettes. These rosettes had several sizes reaching 2.6 mm. They showed a palisade of rounded cells. Nuclei were hyperchromatic but bland. The center was made of eosinophilic cores of collagenous radiating fibrils. Neoplastic cells stained strongly for S‐100 protein. In the capsule, perineural cells stained for epithelial membrane antigen (EMA). No expression of Mucin 4 (MUC4) was present. This was consistent with NLS. The same peculiar appearance of giant rosettes has been described in hyalinizing spindle cell tumor with giant rosettes (HSCT). We propose the term “neuroblastoma‐like schwannoma” when there are small rosettes, “HSCT‐like schwannoma” for tumors with giant rosettes and “collagen‐rich schwannoma” when there are “ill‐defined” structures reminiscent of rosettes. Immunohistochemical panel containing S100, EMA, and MUC4, as well as molecular testing when needed should be performed.

Intranodal palisaded myofibroblastoma (IPM), also known as “intranodal hemorrhagic spindle cell tumor with amianthoid fibers,” is a rare benign mesenchymal tumor originating from smooth muscle cells and myofibroblasts, often with the presence of amianthoid fibers. Usually IPM affects inguinal lymph nodes, but three cases have been described in the submandibular and cervical lymph nodes. We report a new case of a 44-year-old women with submandibular mass. Cervical ultrasound showed a suspect right submandibular adenomegaly. The patient underwent an excision of the submandibular mass. Histological features of the tumor include an encapsulated fusocellular proliferation, with nuclear palisading, amianthoid fibers, hemosiderin pigment, and extravasated erythrocytes. In the light of these results, we made the diagnosis of IPM. No recurrence was found 5 years after surgery.

Erythrokeratodermia variabilis (EKV) is a rare disorder of cornification usually associated with dominant mutations in the GJB3 and GJB4 genes encoding connexins (Cx)31 and 30.3. Genetic heterogeneity of EKV has already been suggested. We investigated at the clinical and genetic level a consanguineous Tunisian family with 2 sisters presenting an autosomal recessive form of EKV to better characterize this disease. Mutational analysis initially screened the connexin genes and Whole-exome sequencing (WES) was performed to identify the molecular aetiology of the particular EKV phenotype in the proband. Migratory shaped erythematous areas are the initial presenting sign followed by relatively stable hyperkeratotic plaques are the two predominates characteristics in both patients. However, remarkable variability of morphological and dominating features of the disease were observed between patients. In particular, the younger sister (proband) exhibited ichthyosiform-like appearance suggesting Autosomal Recessive Congenital Ichthyosis (ARCI) condition. No causative mutations were detected in the GJB3 and GJB4 genes. WES results revealed a novel missense homozygous mutation in NIPAL4 gene (c.835C>G, p.Pro279Ala) in both patients. This variant is predicted to be likely pathogenic. In addition, in silico analysis of the mutated 3D domain structure predicted that this variant would result in NIPA4 protein destabilization and Mg2+ transport perturbation, pointing out the potential role of NIPAL4 gene in the development and maintenance of the barrier function of the epidermis. Taken togheter, these results expand the clinical phenotype associated with NIPAL4 mutation and reinforce our hypothesis of NIPAL4 as the main candidate gene for the EKV-like ARCI phenotype.

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