Takashi Johshita

Small ileal neurofibroma causing intussusception in a non-neurofibromatosis patient

Neurofibromas in the small intestine are usually accompanied by von Recklinghausens disease (neurofibromatosis), and usually originate in the intramuscular plexus of Auerbach. We present here a solitary neurofibroma, which caused an ileocolic intussusception, originating in the submucosal plexus of Meissner in a non-neurofibromatosis patient. To our knowledge, there is no previous report of a neurofibroma originating in the plexus of Meissner. This condition was clearly confirmed by macroscopic and microscopic evaluation.

Reactive Proliferative Lesions in Lymph Nodes from Rheumatoid Arthritis Patients

In 22 cases of rheumatoid arthritis (RA), including 4 cases of malignant RA (MRA), reactive proliferative lymph node lesions were studied clinicopathologically and immunohis‐tochemically. This series included 5 males and 17 females. The period between disease onset and lymph node biopsy ranged from 3 months to 41 years. Generalized lymphadenopathy was noted in 13 cases and constitutional symptoms in 8. The histological findings characteristic of RA were 1) follicular hyperplasia with active germinal centers and 2) polyclonal plasma cell infiltration in the interfollicular area. Studies of intracytoplasmic immunoglobulin showed that γ‐heavy chain‐expressing plasma cells were a major component in the interfollicular area in 17 RA cases. However, in 4 MRA cases, a prominent increase of μ chain‐expressing plasma cells was recognized in the same area. In the 3 cases for which fresh tissue sections were stained with monoclonal antibodies against lymphocytes, we found that the majority of T cells in the interfollicular area had helper/inducer markers. The identical locations of the T cell population and plasma cells indicated that both played a role in the proliferation and/or differentiation of B cells in lymph nodes in RA.

Malignant lymphoma of Waldeyer's ring. A histological and immunohistochemical study.

The histopathological and immunohistological features of non‐Hodgkins lymphoma limited to the Waldeyers ring were studied in 22 Japanese patients using a panel of T‐ and B‐cell markers on paraffin‐embedded sections. All cases showed a diffuse growth pattern. Twenty cases were B‐cell lymphomas and two were T‐cell lymphomas. In contrast to the primary malignant lymphomas of the nasal cavity and paranasal sinuses, in which T‐cell neoplasms are more frequently seen, the majority of the primary Waldeyers ring lymphomas were B‐cell neoplasms. Sixteen of the 20 cases of B‐cell lymphoma were centroblastic lymphomas, and the monomorphic variant comprised the majority of these; the other three B‐cell lymphomas were immunocytomas. Two of the T‐cell lymphomas showed morphological features of angiocentric lymphomas.

Malignant lymphomas of the nasal cavity and paranasal sinuses. A clinicopathologic and immunohistochemical study.

The clinicopathologic and immunohistological features of 20 Japanese patients with non‐Hodgkins lymphomas (NHLs) limited to the sinonasal area were studied using a broad panel of T‐ and B cell markers on paraffin‐embedded and fresh frozen tissue. All cases showed a diffuse growth pattern. Nine cases were B cell lymphomas (immunoblas‐tic n = 4, centroblastic n = 3, immunocytoma n = l, centrocytic n = l), and nine were T‐cell lymphomas (pleomorphic medium and large cell n = 8, angioimmuno‐blastic n = 1). In two cases, the cell lineage could not be determined. No morphologic features of angiocentric/an‐giodestructive lymphoproliferative lesions or lymphoepithe‐lial lesions in ductal or glandular epithelium were seen in our series. Eight (89%) of the nine T‐ cell tumors and four(44%) of the nine B ‐ cell neoplasms involved both the nasal cavity and paranasal sinuses. Six of the nine T ‐ cell neoplasms showed a clinical presentation of rhinitis, whereas all of the B ‐ cell neoplasms showed tumor masses in the nasal cavity and/or paranasal sinuses. The two‐year survival rate for T cell lymphomas was poorer than that for B‐cell lymphomas. The five‐year survival of patients with NHLs involving both the nasal cavity and paranasal sinuses was also poorer than that of patients in whom NHLs were limited to the nasal cavity. Acta Pathol Jpn 42:333–338, 1992.

Monocytoid B Lymphocytes and Epithelioid Cell Clusters in Abscess‐forming Granulomatous Lymphadenitis With Special Reference to Cat Scratch Disease

In order to clarify the appearance of monocytoid B lymphocytes (MBLs) in abscess‐forming granulomatous lymphadenitis (AGL) and the relation between AGL and cat‐scratch disease (CSD), 48 cases of AGL were studied histologically. MBLs were present in about 50% of AGL cases. Warthin Starry (WS) silver stain‐positive bacteria, which are the causative agent of CSD, were present in 52.4% of AGL cases with MBLs and 59.2% of AGL cases without MBLs. The appearance of MBLs in AGL was not related to various clinical features, including disease interval from initial lymphadenopathy to lymph node biopsy. Histologically, epithelioid cell clusters appeared in about 70% of MBL positive AGL cases, but were not observed in MBL negative AGL. Therefore, a close interaction between MBLs and epithelioid cells in AGL is suggested, and we emphasize that the histological features of some AGL cases resemble those of toxoplasmic lymphadenitis.