Department of Anatomical Pathology, Douglass Hanly Moir Pathology, Macquarie Park.
Cancer Diagnosis and Pathology Group, Kolling Institute of Medical Research, Royal North Shore Hospital.
Am J Surg Pathol. 2021 Jun 1;45(6):841-853. doi: 10.1097/PAS.0000000000001659.
We prospectively studied our institutional experience of bladder extranodal marginal zone (mucosa-associated lymphoid tissue [MALT]) lymphoma including bladder biopsies in which the possibility of MALT lymphoma was considered. We identified a subset of cases primary to the urinary bladder, presenting with prominent plasma cell infiltrates and symptoms mimicking bladder pain syndrome/interstitial cystitis. These proliferations were designated for this study as "monotypic plasma cell proliferation of uncertain clinical significance" (MPCP-US), as the features were insufficient for diagnosis of MALT lymphoma. We identified 33 patients, consisting of 22 cases of MPCP-US (6 of which were associated with amyloid deposition) and 11 cases of MALT lymphoma. MPCP-US was more prevalent in men (73%), a mass lesion was not identified at cystoscopy, and only 1 case had an accompanying urinary tract infection (4.5%). Histologically, MPCP-US presented as monotypic plasma cells arranged in a superficial band-like distribution in the lamina propria, predominantly kappa restricted (68%) and IgA+ or IgM+ (64% and 23%, respectively) and without a histologic mass of atypical B cells or plasma cells, not diagnostic for established MALT lymphoma or plasmacytoma. Secondary involvement of the bladder by other lymphoproliferative disorders was excluded and there was no evidence of progressive disease. MALT lymphomas are presented for comparison and our analysis demonstrated that MPCP-US represent a different clinicopathologic entity compared with classic MALT lymphoma. We present the first series of cases of MPCP-US. The recognition of this entity is fundamental to the development of management protocols to relieve intractable symptoms mimicking bladder pain syndrome/interstitial cystitis in these patients.
我们前瞻性地研究了我们机构的经验，包括在考虑边缘区（黏膜相关淋巴组织 [MALT]）淋巴瘤可能性的情况下进行的膀胱活检。我们确定了一组主要发生在膀胱的病例，这些病例表现为明显的浆细胞浸润，并伴有膀胱疼痛综合征/间质性膀胱炎的症状。这些增生被指定用于本研究，称为“不确定临床意义的单型浆细胞增生”（MPCP-US），因为其特征不足以诊断 MALT 淋巴瘤。我们共确定了 33 例患者，其中包括 22 例 MPCP-US（其中 6 例与淀粉样物质沉积有关）和 11 例 MALT 淋巴瘤。MPCP-US 在男性中更为常见（73%），膀胱镜检查未发现肿块，仅有 1 例伴有尿路感染（4.5%）。组织学上，MPCP-US 表现为单型浆细胞呈浅带样分布在固有层，主要为κ限制性（68%）和 IgA+或 IgM+（分别为 64%和 23%），没有组织学上的非典型 B 细胞或浆细胞肿块，不能诊断为已确立的 MALT 淋巴瘤或浆细胞瘤。排除了其他淋巴增生性疾病对膀胱的继发性累及，并且没有疾病进展的证据。MALT 淋巴瘤也进行了呈现以供比较，我们的分析表明，MPCP-US 代表了与经典 MALT 淋巴瘤不同的临床病理实体。我们呈现了 MPCP-US 的第一个病例系列。认识到这一实体对于制定管理方案以缓解这些患者模仿膀胱疼痛综合征/间质性膀胱炎的难治性症状至关重要。
