An unusual presentation of a cystic duplication of the sigmoid colon entirely lined with squamous epithelium.

Alimentary tract duplications are rare congenital malformations that occur most commonly in the jejunoileal part of the gastrointestinal tract. Management of this pathologic condition is usually drawn up. We report a case of descending colonic communicating duplication in which clinical presentation and anatomopathologic results were unexpected.

Atypical hyperplasia of the marginal zone of B follicles in a polymorphic Epstein-Barr virus-associated lymphoproliferative disorder occurring in an adolescent with human immunodeficiency virus infection.

Epstein-Barr virus (EBV)-associated lymphoid proliferations that are similar to post-transplantation lymphoproliferative disorders may occasionally occur in the setting of human immunodeficiency virus (HIV) infection. Herein, we describe such a lesion involving the adenoids in a HIV-seropositive adolescent who acquired immunity against EBV during childhood. On microscopic examination, the marginal zone of B follicles and the interfollicular area were enlarged due to the accumulation of small or intermediate-sized lymphocytes, immunoblasts, epithelioid histiocytes, and plasma cells.

Aggressive pilomatrixoma of the infra-auricular area: a case report.

Although pilomatrixomas are well known among dermatologists and dermatopathologists, head and neck surgeons confronted with these lesions in the infra-auricular region do not consider this benign neoplasm in the differential diagnosis. Aggressive pilomatrixoma is a benign tumor of the hair matrix cells affecting mainly children. Histologically, the border between aggressive pilomatrixoma and pilomatrix carcinoma is still not clear.

Clinically unsuspected tonsillar sarcoidosis in a child revealed by routine histologic examination.

In most hospitals, making a microscopic examination to tonsil and adenoid specimens from pediatric patients who present recurrent infections has become a standard practice. However, studies have shown that systematic examination of tonsils and adenoids was not needed for individual aged 21 or less. In this context, we describe the third report of an unsuspected tonsillar sarcoidosis revealed by histologic examination.