Natural history of NF1 c.2970_2972del p.(Met992del): confirmation of a low risk of complications in a longitudinal study

Individuals with the three base pair deletion NM_000267.3(NF1):c.2970_2972del p.(Met992del) have been recognised to present with a milder neurofibromatosis type 1 (NF1) phenotype characterised by café-au-lait macules (CALs) and intertriginous freckling, as well as a lack of cutaneous, subcutaneous and plexiform neurofibromas and other NF1-associated complications. Examining large cohorts of patients over time with this specific genotype is important to confirm the presentation and associated risks of this variant across the lifespan. Forty-one individuals with the in-frame NF1 deletion p.Met992del were identified from 31 families. Clinicians completed a standardised clinical questionnaire for each patient and the resulting data were collated and compared to published cohorts. Thirteen patients have been previously reported, and updated clinical information has been obtained for these individuals. Both CALs and intertriginous freckling were present in the majority of individuals (26/41, 63%) and the only confirmed features in 11 (27%). 34/41 (83%) of the cohort met NIH diagnostic criteria. There was a notable absence of all NF1-associated tumour types (neurofibroma and glioma). Neurofibroma were observed in only one individual—a subcutaneous lesion (confirmed histologically). Nineteen individuals were described as having a learning disability (46%). This study confirms that individuals with p.Met992del display a mild tumoural phenotype compared to those with ‘classical’, clinically diagnosed NF1, and this appears to be the case longitudinally through time as well as at presentation. Learning difficulties, however, appear to affect a significant proportion of NF1 subjects with this phenotype. Knowledge of this genotype–phenotype association is fundamental to accurate prognostication for families and caregivers.

Salivary Duct Carcinoma in the External Auditory Canal Causing Ipsilateral Hearing Loss

Background: Salivary duct carcinoma (SDC) is a rare aggressive tumor. Most tumors are not confined to the salivary ducts; rather, they invade the major and minor salivary glands. Only a few case reports on such tumors in other primary sites have appeared. Case presentation: A 40-year-old male complained of right hearing loss (a common condition), but we made an extremely rare diagnosis of an SDC in the external auditory canal (EAC). EAC cancers are frequently misdiagnosed. In our patient, the otoscope revealed a smooth, bulging subcutaneous lesion with a non-epithelial defect suggestive of a benign lesion. However, an SDC of the EAC was confirmed through pathological and immunohistochemical analysis. Conclusions: We suggest detailed evaluation of even smooth EAC subcutaneous lesions to avoid erroneous diagnoses. To the best of our knowledge, this is the first report of SDC in the EAC.

Malignant Subcutaneous Perivascular Epithelioid Cell Tumor of Anterior Abdominal Wall

Perivascular epithelioid cell tumors (PEComas) are a family of rare mesenchymal tumors with discrete histological and immunohistochemical characteristics. Even rarer among them are cutaneous and subcutaneous PEComas. We describe a 34-year-old woman who presented with a large anterior abdominal subcutaneous lesion showing intact overlying skin and no obvious invasion of the abdominal musculature. A wide local excision was performed. Histopathology revealed a solitary tumor measuring 75 × 55 × 90 mm with epithelioid cells in nests with thin fibrovascular septa and spindle cells. Resection margins were clear with no invasion to the skin or rectus sheath. Tumor cells were positive for HMB-45 but negative for other markers. This is the largest subcutaneous PEComa reported to date.

Sclerotherapy complications of peripheral venous malformations

Background Sclerotherapy is often the primary treatment for peripheral venous malformations. It is mostly sufficient alone, but can be combined with other endovascular techniques. Despite its mini-invasiveness, it is not without potentially severe complications. Here, we systematically report sclerotherapy complications in trunk and extremity venous malformations. Methods We retrospectively assessed the complications of 127 consecutive patients who had received sclerotherapy for peripheral venous malformation in our tertiary care unit (January 2007–August 2013). We applied the Clavien–Dindo classification to grade the severity of complications. We mostly used detergent sclerosants (85.7%), and less often ethanol (5.7%) or bleomycin (4.2%). In 4.2% of the procedures, we combined glue, coils, endovascular laser or particles to sclerotherapy. Results The overall complication rate per procedure was 12.5%. Most complications (83.3%) were local and managed conservatively. We encountered four severe complications, all related to blood coagulopathy. Subcutaneous lesion location and use of ethanol significantly increased the risk of local complications. Conclusion Sclerotherapy alone or combined with other endovascular techniques is a safe method for local venous malformations with moderate risk for conservatively manageable complications. Blood coagulopathy constitutes a risk for, otherwise rare, severe complications.