Ectopic modified sebaceous glands in human penis

External genitalia phenotypes of a Mab21l1-null mouse model for cerebellar, ocular, craniofacial, and genital (COFG) syndrome

The cerebellar, ocular, craniofacial, and genital (COFG) syndrome is a human genetic disease that is caused by MAB21L1 mutations. A COFG mouse model with Mab21l1-null mutation causes severe microphthalmia and fontanelle dysosteogenesis, similar to the symptoms in human patients. One of the typical symptoms is scrotal agenesis in male infants, while male Mab21l1-null mice show hypoplastic preputial glands, a rodent-specific derivative of the cranial scrotal fold. However, it is still unclear where and how MAB21Ll acts in the external genitalia in both mice and humans. Here we show that, at the neonatal stage, MAB21L1 expression in the external genitalia was restricted to two mesenchymal cell populations-underneath the scrotal and labial skin and around the preputial and clitoral glands (PG/CG). Morphometric analyses of the Mab21l1-/- pups revealed a significant reduction in the external size of the scrotum, vulva, and CG, as well as PG. In the periglandular region around PG and CG, the periglandular mesenchymal cells showed a drastic reduction in both cell density and immunoreactive signals for several extracellular matrix proteins (e.g., collagen I, fibronectin, and proteoglycans), together with their reduced Ki67-positive cell proliferation index. In the Mab21l1-/- PG/CG, together with reduced vascularization, the glandular epithelia displayed atrophy with discontinuous basal lamina along the basal surface and defective glycogen accumulation in their cytoplasm. Under a 5-day organ culture of the isolated PG, the Mab21l1-/- explants showed poor outgrowth and retention of the glandular structure in vitro. However, the addition of exogenous Matrigel could partially rescue such tissue-autonomous phenotypes, showing glandular morphology similar to that of the wild-type explants. These findings suggest that MAB21L1+ mesenchymal cells play a crucial role in providing nutrient ECM support for glandular outgrowth and morphogenesis in the peripheral external genitalia.

Sebaceous neoplasia and the Muir-Torre syndrome: important connections with clinical implications

Sebaceous neoplasia comprises a spectrum ranging from benign to malignant. Proper histological identification is important for treatment, prognosis and potential association with the Muir-Torre syndrome (MTS). Our increased understanding of the significance and pathogenesis of these tumours has led to improved risk stratification, screening recommendations, and treatment of patients with an initial presentation of a sebaceous tumour. This review focuses on the diagnostic and histological features of sebaceous lesions, the MTS, and recent insights into the molecular pathogenesis of sebaceous tumours.

Multiple tiny ectopic sebaceous glands discovered throughout entire esophageal tract

A 45-year-old woman complaining of abdominal fullness was referred for endoscopic examination. She was a non-smoker and non-drinker. An endoscopic examination revealed the presence of more than 100 tiny, rounded, elevated, yellowish lesions <0.5 mm in diameter scattered throughout the upper and lower esophagus. Based on the endoscopic examination results, her stomach manifested symptoms of mildly superficial gastritis. Histopathologic examination of the esophagus biopsy specimen revealed that some of the lobules of the cells displayed typical sebaceous differentiation covered by a squamous epithelium. No evidence of inflammatory reaction, hair follicles, or malignancy was found. The patient's blood and serum findings were unremarkable. Our final diagnosis was multiple tiny ectopic sebaceous glands in the esophagus. This is an interesting and rare case of esophageal sebaceous glands distributed throughout the entire esophagus. Because there were no esophageal symptoms or/and eating problems, the patient did not require endoscopic surgery or other treatment. Follow-up examinations were recommended at intervals between 6 months and 1 year. At the 2-year follow-up, an endoscopic examination revealed no change in the size or the number of the tiny ectopic esophageal sebaceous glands.