Pituitary apoplexy secondary to thrombocytopenia due to dengue hemorrhagic fever: a case report and review of the literature.

OBJECTIVE: To present a case of pituitary apoplexy secondary to thrombocytopenia associated with dengue hemorrhagic fever (DHF). METHODS: In this case study, we review the presentation, evaluation, diagnosis, and management of a case of pituitary apoplexy in the setting of DHF. We also searched the literature for cases of pituitary apoplexy associated with thrombocytopenia and review their clinical presentation, management, and outcome. RESULTS: A 53-year-old man presented with fever, lethargy, and worsening headache. Routine investigations revealed thrombocytopenia secondary to dengue fever. He developed symptoms of a cavernous sinus lesion the next day. Urgent magnetic resonance imaging revealed pituitary apoplexy in a pituitary macroadenoma. A transsphenoidal surgery was done and histology was consistent with apoplexy in a prolactin/follicle-stimulating hormone macroadenoma. Subsequently, the patient developed permanent deficits of anterior pituitary hormones. We review 8 other cases of pituitary apoplexy associated with thrombocytopenia reported in the literature. CONCLUSION: Thrombocytopenia due to various causes may be a predisposing factor for pituitary apoplexy in a patient with underlying pituitary disease. In view of the tendency for bleeding associated with thrombocytopenia, the risks of surgical intervention have to be carefully weighed against the potential benefits. Indications for surgery would include progressive alteration of consciousness, visual disturbances, and opthalmoplegia despite conservative management. Patients with underlying pituitary macroadenomas with optic chiasm compression have a worse prognosis, and the chances of recovery, even with early surgery, are limited.

Mammary analogue secretory carcinoma: the first submandibular case reported including findings on fine needle aspiration cytology.

We present the first case (male, 35 years old) of a mammary analogue secretory carcinoma occurring in a submandibular gland and document findings on fine needle aspiration cytology. On histology, the tumor displayed characteristic features: circumscribed nodules composed of bland, pink to light red neoplastic cells with low proliferative/mitotic activity arranged in tubular, vaguely cribriform, and microcystic structures containing Periodic acid Schiff-positive, diastase-resistant secretory material. Immunohistochemistry showed strong and diffuse positivity for cytokeratin 7, S100 protein, and vimentin, as well as moderate to strong immunoreactivity for c-kit in the majority of tumor cells. A rearrangement of the ETV6 gene on fluorescence in situ hybridization was documented. The patient underwent an ipsilateral selective (levels I-IV) neck dissection which showed metastasis in 3 out of 36 lymph nodes (levels 1-3). Adjuvant radiotherapy was administered. No local recurrence or metastatic disease has been detected during a follow up period of 28 months.

Diffuse large B-cell lymphoma associated with chronic inflammation as an incidental finding and new clinical scenarios.

Diffuse large B-cell lymphoma that develops in the setting of long-standing chronic inflammation is typically associated with Epstein-Barr virus, and usually presents as tumor mass involving body cavities, as in pyothorax-associated lymphoma. It is listed as a distinct entity in the latest World Health Organization lymphoma classification. We report four cases that were incidentally discovered on histologic examination, one each in a splenic false cyst, a long-standing hydrocele, an atrial myxoma, and metallic-implant wear debris. Microscopic foci of atypical (neoplastic) large lymphoid cells were found within the contents of the cysts or curettage material, or within the stroma of the atrial myxoma. Despite the diverse clinical scenarios, all cases showed a homogeneous phenotype: positivity for B-lineage markers (CD20+, CD79a+, PAX5+), non-germinal center immunophenotype (CD10-, BCL6-/+, MUM-1+), and positivity for Epstein-Barr virus with type III latency (LMP1+, EBNA2+). The last feature supports the hypothesis that the lymphoma has arisen in a setting of 'local immunodeficiency' as a result of long-standing chronic inflammation in an enclosed space, a characteristic pathogenetic mechanism of diffuse large B-cell lymphoma associated with chronic inflammation. These cases therefore expand the spectrum of this entity to include new clinical scenarios for the development of this lymphoma type.

Germline bone morphogenesis protein receptor 1A mutation causes colorectal tumorigenesis in hereditary mixed polyposis syndrome.

OBJECTIVES: Hereditary mixed polyposis syndrome (HMPS) is characterized by polyps of mixed adenomatous/hyperplastic/atypical juvenile histology that are autosomal dominantly inherited and that eventually lead to colorectal cancer (CRC). Although CRC with adenomatous polyps is initiated by inactivating adenomatous polyposis coli (APC), the initiating event of CRC with mixed polyps remains unclear. We aimed to identify the underlying germline defect in HMPS. METHODS: We screened for bone morphogenesis protein receptor 1A (BMPR1A) mutation by exonic sequencing, reverse-transcriptase polymerase chain reaction (PCR) followed by cDNA sequencing, and multiplex ligation-dependent probe amplification (MLPA) analysis in eight Singapore Chinese HMPS families. RESULTS: Germline BMPR1A defects were found in four (50%) families. In two families, it is shown to co-segregate with the disease phenotype in all affected members over three generations, indicating that it is the disease-causing mutation. CRC incidence is 75%. The most defining characteristic is the presence of mixed hyperplastic-adenomatous polyps. Juvenile polyps are rarely reported, and if present, are usually of mixed components. Detailed histology of the polyps from one patient over 11 years distinguishes HMPS from juvenile polyposis syndrome (JPS). We report further the first cases of Wilms' tumor and papillary thyroid carcinoma associated with BMPR1A germline defect. CONCLUSIONS: Germline BMPR1A defect is the disease-causing mutation in 50% of the HMPS families. If patients present with mixed morphology polyps in the large bowel that are autosomal dominantly inherited and corresponding absence of upper gastrointestinal abnormalities, the gene to begin mutation screening should be BMPR1A rather than APC.

External jugular vein vascular malformation: sonographic and MR imaging appearances.

Vascular malformations arising from the wall of the external jugular vein are rare. This case series discusses the sonographic and MR imaging appearances of four such cases and reviews the literature. The diagnosis should be suggested preoperatively particularly because of the close relationship such malformations to the external jugular vein, as this helps surgeons to plan the operative procedure. The imaging appearances are similar to those of other vascular malformations elsewhere in the head and neck.