Mucosa-associated lymphoid tissue (MALT) lymphoma of the jejunum: an elusive cause of recurrent upper gastrointestinal bleeding

MALT lymphoma often involves the stomach but much less commonly the small bowel. We present clinico-pathologic and radiologic features of a patient with recurrent gastrointestinal bleeding due to MALT lymphoma of the jejunum. Because of the small bowel location, the source of bleeding has been elusive, resulting in delayed diagnosis. The diagnosis was based on the small B cell morphology, demonstration of lympho-epithelial lesions, and immunophenotypic profile.     

Atypical blasts and bone marrow necrosis associated with near-triploid relapse of acute promyelocytic leukemia after arsenic trioxide treatment

The pathologic features of acute promyelocytic leukemia (APL) with t(15;17)(q22;q21) are highly characteristic, which with few exceptions enable a firm diagnosis to be made on morphologic grounds. An APL patient in first relapse presented with large, bizarre circulating blasts and bone marrow necrosis 2 weeks after chemotherapy consolidation for an arsenic trioxide-induced remission. Although a morphologic diagnosis could not be reached, cytogenetic investigations showed a near-triploid clone with t(15;17), confirming APL in second relapse. This case showed that clonal evolution with additional karyotypic aberrations might alter the blast morphology and pathologic features in APL.     

Primary CD56 positive lymphomas of the gastrointestinal tract

BACKGROUND: Primary CD56 positive lymphoma of the gastrointestinal (GI) tract is rare. Genotypically, these tumors can be classified into natural killer (NK)-like T-cell lymphoma or NK cell lymphoma by the presence or absence of T-cell receptor (TCR) gene rearrangement. However, they have a considerable degree of morphologic and immunophenotypic overlap, making a definitive diagnosis difficult. METHODS: The clinicopathologic features of three patients with primary CD56 positive lymphoma of the small and large bowel are presented. This is followed by a review of the English literature from 1966 to the present. RESULTS: All patients had CD56 positive/CD3epsilon positive disease on paraffin section. Two patients were positive for Epstein-Barr virus-encoded early nuclear RNAs (EBER) according to in situ histochemistry results and were negative for TCR gene rearrangement, consistent with primary NK lymphoma of the GI tract. The other patient was EBER negative with rearranged TCR, consistent with NK-like T-cell lymphoma. There was no clinical or histologic evidence of enteropathy in any of the patients. The major presenting symptoms included fever, weight loss, and intestinal perforation. All patients died between 1 week and 6 months after diagnosis despite undergoing surgery and intensive chemotherapy. CONCLUSIONS: These results, together with a literature review, suggest that primary NK cell lymphoma of the GI tract may be considered a distinct clinicopathologic entity. Both primary NK and NK-like T-cell lymphoma pursue an aggressive clinical course. EBER and TCR gene rearrangement are useful in distinguishing NK cell lymphoma from NK-like T-cell lymphoma, particularly when frozen tissue is not available for immunophenotyping.     

Absence of gallium uptake in multicentric Castleman's disease of plasma cell type

Multicentric Castleman's disease (MCD) of plasma cell type is a reactive lymphoproliferative disease. While 67Ga scanning is useful in the detection of malignant lymphomas, its role in reactive lymphadenopathy is unknown. We report the absence of 67Ga uptake in three patients with MCD of plasma cell type and present a review of the English literature on this condition.     

Keyhole surgery for isolated pituitary stalk metastatic tumors: a case report and review of the literature

Solitary metastatic pituitary stalk tumors account for approximately less than 1% of all pituitary gland tumors and present difficulties in clinical diagnosis because most of them are clinically silent and usually too small to cause radiological changes. With the advance of microsurgical techniques, keyhole surgery is indicated to obtain a specimen for pathological diagnosis and possible removal of the tumor. Here, we reported a patient who has a history of advanced breast cancer and who complained of polyuria and polydypsia. Magnetic resonance images revealed a solitary tumor over the pituitary stalk. A right supraorbital craniotomy was performed and the pathological report confirmed the diagnosis of metastatic breast cancer. This is the first case report using keyhole surgery to confirm the pathology and improve the clinical symptoms. The relevant literature is also reviewed.     

Low-energy helium–neon laser induces melanocyte proliferation via interaction with type IV collagen: visible light as a therapeutic option for vitiligo

Background The treatment of vitiligo remains a challenge for clinical dermatologists. We have previously shown that the helium–neon laser (He–Ne laser, 632·8 nm) is a therapeutic option for treatment of this depigmentary disorder. Objectives Addressing the intricate interactions between melanocytes, the most important cellular component in the repigmentation scheme of vitiligo, and their innate extracellular matrix collagen type IV, the current study aimed to elucidate the effects of the He–Ne laser on melanocytes. Methods Cultured melanocytes were irradiated with the He–Ne laser. Relevant biological parameters including cell attachment, locomotion and growth were evaluated. In addition, the potentially involved molecular pathways were also determined. Results Our results show that in addition to suppressing mobility but increasing attachment to type IV collagen, the He–Ne laser stimulates melanocyte proliferation through enhanced α2β1 integrin expression. The expression of phosphorylated cyclic‐AMP response element binding protein (CREB), an important regulator of melanocyte growth, was also upregulated by He–Ne laser treatment. Using a specific mitochondrial uncoupling agent [carbonyl cyanide m‐chlorophenyl‐hydrazone (CCCP)], the proliferative effect of the He–Ne laser on melanocytes was abolished and suppression of melanocyte growth was noted. Conclusions In summary, we have demonstrated that the He–Ne laser imparts a growth stimulatory effect on functional melanocytes via mitochondria‐related pathways and proposed that other minor pathways including DNA damage may also be inflicted by laser treatment on irradiated cells. More importantly, we have completed the repigmentation scheme of vitiligo brought about by He–Ne laser light in vitro and provided a solid theoretical basis regarding how the He–Ne laser induces recovery of vitiligo in vivo.