Efficacy of Touch Imprint Cytology in Intraoperative Diagnosis of Invasive Mucinous Adenocarcinoma of the Lung: A Case Report and Literature Review.

A preoperative diagnosis of the peripheral small lung nodule is often difficult, and an intraoperative frozen section diagnosis (FSD) is performed to guide treatment strategy. However, invasive mucinous adenocarcinoma (IMA) is prone to be overlooked because of the low sample quality and weak atypia. We herein report a case of IMA, in which touch imprint cytology (TIC) revealed diagnostic efficacy. A 74-year-old male with a small, subsolid nodule in the right upper lobe underwent a thoracoscopic wedge resection. A grayish brown, 10 × 7 mm-sized nodule was observed on the cut surface. Intraoperative FSD revealed lung tissue with mild alveolar septal thickening and stromal fibrosis but without overt atypia. Meanwhile, TIC revealed mucus and a few epithelial cells with intranuclear inclusions, which pathologists evaluated as reactive. Finally, focal organizing pneumonia was tentatively diagnosed, and surgery was finished without any additional resection. However, permanent section diagnosis revealed a microinvasive mucinous adenocarcinoma. Nuclear inclusions were confirmed in tumor cells. In the intraoperative setting, TIC may be more advantageous than FSD in observing nuclear inclusions and mucus. Mucinous background and nuclear inclusion on TIC may suggest IMA even if FSD does not suggest malignancy in an intraoperative diagnosis of the peripheral small lung nodule.

An unusual cytological presentation of solid pseudopapillary neoplasm of the pancreas mimicking adenoid cystic carcinoma: a case report and literature review.

Endoscopic ultrasound-guided fine-needle aspiration has become the common procedure for the diagnosis of pancreatic mass, and cytological examination is usually the first approach. Solid pseudopapillary neoplasm (SPN) cytologically represents papillary structures of branching capillaries surrounded by discohesive neoplastic cells. However, it may present various degrees of tissue degeneration, causing diagnostic challenges. Here, we report a 21-year-old female who had a 2-cm-sized mass in the pancreas head. Cytological examination revealed clumps of small round/oval cells that represented microcystic configurations with mucus, mimicking adenoid cystic carcinoma or mucinous adenocarcinoma. Cercariform cells, nuclear grooves/folding, and cytoplasmic vacuoles were not observed. Histopathological examination revealed confluent small glandular structures containing acidic mucus. The tumor cells were positively stained for ß-catenin, CD10, and CD56, and negative for chromogranin A and E-cadherin, suggesting SPN, micropseudocystic variant. This variant has been scarcely described, but we should recognize it for accurate cytological triage of pancreatic tumors.

Reclassification of atypical immature metaplasia of the uterine cervix by combination of nuclear features on hematoxylin and eosin-stained sections without auxiliary immunohistochemistry.

Reclassification of endocervical atypical immature metaplasia (AIM) into reactive changes and neoplastic lesion is often challenging. We aimed to accurately reclassify AIM on hematoxylin and eosin (HE)-stained sections without auxiliary immunohistochemistry (IHC). A total of 133 AIM diagnosed by punch biopsy were reclassified by IHC for p16 and Ki-67 into high-grade squamous intraepithelial lesion (HSIL) or negative for intraepithelial lesion or malignancy or low-grade squamous intraepithelial lesion (NILM/LSIL) as a reference. Nuclear features significantly associated with HSIL on HE-stained sections were extracted by multivariate logistic regression analysis. Propensity score (PS) of HSIL was calculated in each case and cut-off was determined by receiver operation characteristic (ROC) curve analysis. As a result, AIM was reclassified into 104 NILM/LSIL and 29 HSIL by IHC. Compared with reference diagnosis, accuracy of pathologists' subjective diagnosis was 54.9% (kappa coefficient, 0.208). Three nuclear features on HE-stained sections, ie, nuclear enlargement with anisokaryosis, nuclear hyperchromasia, and mitosis, were significantly associated with HSIL. The ROC curve analyses revealed that PS and number of nuclear features were significant predictors of HSIL. Diagnostic accuracy of PS-based diagnosis was 76.7% (kappa, 0.447). When AIM with 2 or more of the 3 nuclear features was diagnosed with HSIL, diagnostic accuracy was 77.4% (kappa, 0.448). Nuclear feature-based diagnosis significantly improved diagnostic accuracy on HE-stained sections compared with subjective diagnosis and may be useful when IHC is not available. However, a considerable proportion of AIM would still remain misdiagnosed and IHC for p16 and Ki-67 should be mandatory for accurate reclassification.

Long-term survival case of esophageal carcinosarcoma coexisting with alcoholic liver cirrhosis successfully treated by staged operation: A case report.

INTRODUCTION: Patients with esophageal cancers including carcinosarcoma sometimes have underlying liver cirrhosis because of a history of heavy drinking. It is definitely required to determine the appropriate surgical strategy and to manage the patients promptly when performing esophagectomy for the esophageal carcinosarcoma coexisting with alcoholic liver cirrhosis. PRESENTATION OF CASE: A 56-year-old male patient with a history of chest pain and difficulty swallowing was admitted to our hospital. He had a history of drinking 250 g of alcohol per day. Endoscopy revealed an irregular protruding tumor on the left wall of the lower-third thoracic esophagus. Computed tomography showed a tumor lesion in the lower-third thoracic esophagus; the images also showed irregularities on the surface of the liver, suggestive of coexisting alcoholic liver cirrhosis. The preoperative diagnosis was T3N2M0, Stage III esophageal leiomyosarcoma. In consideration of the underlying alcoholic liver cirrhosis, a staged operation was planned for this patient as a curative treatment. The patient had an uneventful postoperative clinical course and was discharged on the 47th day after the first surgery. Final histopathological diagnosis was T2N0M0, Stage II esophageal carcinosarcoma. The patient is alive without recurrence three years after surgery. DISCUSSION: This is the first report of long-term survival case of esophageal carcinosarcoma with alcoholic liver cirrhosis that was treated successfully by staged operation. CONCLUSIONS: Despite coexisting with alcoholic liver cirrhosis, staged operation could reduce the surgical invasiveness, so that very good short-term outcome and long-term survival was obtained in the patient with esophageal carcinosarcoma.

EBV(+) B-cell lymphoproliferative disorder associated with subsequent development of Burkitt lymphoma in a patient with idiopathic CD4(+) T-lymphocytopenia.

We report here a case of idiopathic CD4(+) T-lymphocytopenia (ICL) associated with Epstein-Barr virus (EBV)(+) lymphoproliferative disorder (LPD) terminating in Burkitt lymphoma (BL). A 33-year-old Japanese male was admitted to the hospital showing severe CD4(+) lymphocytopenia and neutropenia that was diagnosed as ICL in 1993. Twenty months after the onset of disease, right cervical lymphadenopathy was detected. Biopsy of the specimen showed reactive lymph node hyperplasia and interfollicular B-cell hyperplasia. Ninety-one months later, polypoid tumors were resected from the bilateral nasal cavities and were diagnosed as BL. Immunohistological studies suggested the reactive nature of the initial lymph node biopsy specimen. Polymerase chain reaction (PCR) analyses of immunoglobulin heavy-chain gene (IgH) demonstrated a polyclonal pattern in the initial lymph node lesion. However, the subsequent BL demonstrated a clonal band in the PCR assay for the IgH gene. As demonstrated in human immunodeficiency virus (HIV)-patients, clonal expansion of EBV infected B-cells in the initial lymph node lesion may progress to BL in this patient. The present case did not associate with severe opportunistic infections during the course of disease. EBV(+) BL may be the first manifestation of severe immunodeficiency of the ICL in this patient.

Küttner's tumor of the submandibular glands: report of five cases with fine-needle aspiration cytology.

Küttner's tumor (KT) is a benign tumor-like lesion of the salivary gland that mimics neoplasm clinically because of presentation as a hard mass. Recently, the histomorphological and immunohistochemical findings of this lesion have been analyzed, and differential diagnostic problems relating to salivary gland lymphoma have been discussed. However, currently there is little information on the cytological findings of those lesions. We present cytological findings from five such cases using fine-needle aspiration cytology (FNAC). FNAC of this lesion may present a diagnostic challenge to the cytologist as lesions share some cytologic features with inflammatory process containing numerous lymphoid cells. Smears obtained from two cases contained moderate to large numbers of lymphoid cells without definite cytological atypia, scattered ductal structures, and acinar cell clusters. The remaining three cases showed low cellularity probably attributable to fibrosis that made it difficult to aspirate the cellular element. FNAC findings of scattered ductal structures surrounded by collagens and infiltrated by a mixed population of lymphoid cells, not specific for KT, are highly suggestive of the diagnosis with the appropriate clinical findings. However, a portion of cytological specimens of KT containing relatively large numbers of lymphoid cells should be differentiated from malignant lymphoma arising from the submandibular gland.

Marginal zone B-cell lymphoma of minor salivary gland representing tumor-forming amyloidosis of the oral cavity. A case report.

We report here a case of mucosa-associated lymphoid tissue (MALT)-type lymphoma arising from the minor salivary gland of the oral cavity exhibiting tumor-forming amyloidosis. The patient was a 64-year-old Japanese woman who presented with 4-year history of a left soft palate mass. Despite multiple and multifocal recurrences including the lip, soft palate, tongue, oral base and vocal code and soft palate, the tumor remained localized in the upper aerodigestive tract, and the patient did not develop multiple myeloma during the course of disease. Histologically, the majority of the lesion was occupied by amyloid deposition. Only the periphery of the lesion contained numerous plasmacytoid cells, along with occasional centrocyte-like cells. In addition, lymphoepithelial lesion and follicular colonization were noted. The present case indicates that primary minor salivary gland MALT-type lymphoma appears to be the cause of tumor-forming amyloidosis of the upper aerodigestive tract including the larynx.

Rectal cancer associated with chronic lymphocytic leukemia.

It has been reported that chronic lymphocytic leukemia (CLL) often occurs concomitantly with other malignant neoplasms. However, because CLL is rare in Japan, there are only a limited number of reports of the occurrence of malignant neoplasia in Japanese patients with CLL. We report here the simultaneous occurrence of rectal cancer and CLL in a 57-year-old man. Because the clinical stage of CLL was Rai system I, we decided, in accordance with the National Cancer Institute-Sponsored Working Group guidelines, to monitor him without therapy for CLL until evidence of disease progression, and we performed abdominoperineal resection of the rectum for the cancer. The small rectal tumor was associated with aggressive lymphangiosis carcinomatosa, and multiple nodal metastases were observed in the pool of CLL cells. He died of rectal cancer 7 months after the operation, and autopsy revealed extensive metastases of the cancer. Cellular and humoral immunity is often impaired in patients with CLL, and the defective immunity in this patient may have had an etiological role in the development and rapid progression of the cancer. In the follow-up of CLL patients, we must always be aware of the possible existence of a second malignant disease. Particular attention should be paid to those with defective immunity, and screening should be performed, especially for pulmonary and gastrointestinal malignancies.

Clinical implication of dermatopathic lymphadenopathy among Japanese: a report of 19 cases.

To clarify the clinicopathologic and immunohistochemical features of dermatopathic lymphadenopathy not associated with mycosis fungoides among Japanese, 19 patients were studied. Seventy-four percent of the patients were more than 50 years old (median; 63 years, mean 61 years). Systemic symptoms such as fever were recorded in 68% and multicentric lymphadenopathy was noted in 83% of patients. An association of autoimmune disease or positivity of autoantibodies was recorded in 6 patients. Five patients showed cutaneous hypersensitivity reactions to a drug. Histologically, in addition to the dermatopathic lymphadenopathy, numerous immunoblasts were observed in 2 cases and sheet-like proliferation of mature plasma cells in 3 cases. Various atypical or malignant lymphoproliferative disorders exhibiting immunologic abnormalities such as angioimmunoblastic T-cell lymphoma or autoimmune disease-associated lymphadenopathy frequently occur in middle-aged and elderly patients. At least some of the patients with dermatopathic lymphadenopathy should be clinicopathologically differentiated from these lymphoproliferative disorders.

Clinical implication of idiopathic plasmacytic lymphadenopathy with polyclonal hypergammaglobulinemia: a report of 16 cases.

Idiopathic plasmacytic lymphadenopathy (IPL) with polyclonal hyperimmunoglobulinemia is considered identical to multicentric Castleman's disease (MCD) reported in western countries. Clinically, both IPL and MCD are characterized by multicentric lymphadenopathy, prominent polyclonal hypergammaglobulinemia, elevated erythrocyte sedimentation rate, elevated serum interleukin-6 concentration, bone marrow plasmacytosis, and various abnormal laboratory data such as anemia and positive autoantibodies. However, IPL has a significantly better 5-year survival rate than that of MCD. Moreover, none of the present 16 cases developed Kaposi's sarcoma or B-cell lymphoma. Histologically, the interfollicular area contains a sheet of polytypic mature plasma cells in both IPL and MCD. In MCD, the majority of lymphoid follicles had hyaline-vascular germinal centers. However, lymphoid follicles of IPL usually exhibit a hyperplastic germinal center. Immunostaining also demonstrated a normal/reactive follicular dendritic cell network pattern in the germinal center of IPL. Moreover, there were no human herpes virus-8-positive cells detected by immunohistochemistry. The overall clinicopathologic and immunohistochemical findings of our 16 cases suggest that IPL is distinct from MCD reported in Western countries.

Hepatic angiomyolipoma resembling an inflammatory pseudotumor of the liver. A case report.

Hepatic angiomyolipoma (AML) may demonstrate a marked histologic diversity and is frequently misdiagnosed. HMB45 is a promising marker for this tumor and is expected to facilitate the recognition of some AMLs with unusual morphology. We report on a case of hepatic AML exhibiting histologic features that were similar to inflammatory pseudotumor (IPT) or to IPT-like follicular dendritic cell (FDC) tumor of the liver. The patient was a 21-year-old Japanese woman with a mass in the left lobe of the liver (70 x 73 mm). There were no clinical features of tuberous sclerosis. Histologically, numerous inflammatory cells, including small lymphocytes, plasma cells, and histiocytes, showed diffuse infiltration throughout the lesion. However, the present case also shared some of the morphologic findings of hepatic AML, including clusters of smooth muscle cells with clear cytoplasm, a few scattered adipose cells, and thick-walled blood vessels. Moreover, the smooth muscle cells consisted of spindle-shaped cells or larger, more rounded cells with either clear cytoplasm or eosinophilic epithelioid cell features positive for vimentin, muscle-specific actin, and smooth muscle actin. HMB45 immunostaining confirmed the diagnosis of AML. The present case indicates that IPT or IPT-like FDC tumor should be added to the list of differential diagnoses for AML of the liver.

The role of radiotherapy for thymic carcinoma.

OBJECTIVE: The aim of this study is to evaluate retrospectively the role of radiotherapy for thymic carcinoma. METHODS: Between 1973 and 1998, 14 patients with thymic carcinoma were treated at Gunma Prefectural Cancer Center. Two patients who had hematogenous metastasis were excluded from this study, therefore 12 patients were analyzed. The Masaoka staging system was used; four patients were diagnosed with stage III disease and eight patients with stage IV disease. The pathological subtype according to the World Health Organization histological criteria for thymic tumors was squamous cell carcinoma (low-grade histology) in six cases and undifferentiated carcinoma (high-grade histology) in six. Ten patients underwent thoracotomy, and two patients underwent excisional biopsy without thoracotomy. Ten patients (83%) received radiotherapy as a curative intent, and the median dose was 60 Gy. Systemic chemotherapy was administered to four patients (33%), and the majority (75%) of the regimens contained cisplatin. RESULTS: The 3-year overall survival rate was 25%. Histological subtype (low-grade versus high-grade), surgical resection (complete versus incomplete), radiotherapy and chemotherapy were evaluated as prognostic factors in a univariate analysis. Low-grade histology and complete resection were good prognostic factors, although these were not statistically significant. Patients who received radiotherapy had a better outcome than those who did not. The major sites of recurrence were the pleura and pericardium. Recurrence within the radiation field was observed in one of seven patients in whom failure patterns could be evaluated. CONCLUSION: Complete resection is mandatory if possible. Radiotherapy plays an important role in treating thymic carcinoma in terms of reducing local recurrence and prolonging survival time. Establishment of an innovative treatment protocol that includes chemotherapy is necessary to control intrathoracic relapse and distant metastasis.

Epstein-Barr virus-related lymph node lesion resembling autoimmune disease-like clinicopathological findings in elderly patients. Report of three cases.

Three cases of Epstein-Barr virus (EBV)-related lymphoproliferative disorders in elderly patients showing autoimmune disease-associated lymphadenopathy-like clinicopathological findings have been reported. Clinically, they were characterized by systemic lymphadenopathy, "B" symptoms, polyclonal hypergammaglobulinemia, elevated serum LDH and transient presence of various autoantibodies, and absence of atypical lymphocytosis in peripheral blood. One case was associated with idiopathic thrombocytopenic purpura. The clinical course was self-limiting. Histologically, they exhibited numerous lymphoid follicles with hyperplastic germinal centers and atypical interfollicular widening with prominent vascular proliferation. In the paracortical area, there was a mixed infiltrate comprising small to medium-sized lymphocytes and plasma cells, and variable numbers of eosinophils and T- and B-immunoblasts. In situ hybridization demonstrated a varying number of EBV-infected lymphocytes in the germinal center as well as in the interfollicular area. Polymerase chain reaction demonstrated that neither clonal rearrangement of T-cell receptor gamma-gene nor immunoglobulin heavy-chain rearrangement was detected in two of the cases examined. Although acute EBV infection rarely occurs in older adults, EBV related to reactive lymphoproliferative disorder should be added to the differential diagnosis of autoimmune disease-associated lymphadenopathy and node-based peripheral T-cell lymphoma in elderly patients.

Sclerosing variant of follicular lymphoma arising from submandibular glands and resembling "Küttner tumor": a report of 3 patients.

We present 3 patients with a sclerosing variant of follicular lymphoma that arose from the submandibular gland and resembled "Küttner tumor." All 3 patients developed a painless unilateral tumor in the submandibular region. Histologically, all 3 lesions were categorized as follicular lymphoma grade 2. The neoplastic follicles were found to be separated by thick connective tissue, and periductal chronic inflammation with periductal fibrosis and duct ectasia was found in the residual atrophic gland. Immunohistochemistry revealed that all of the lesions contained a monoclonal tumor cell population. The immunophenotyopes of the lymphoma cells were CD 10+, CD 20+, CD 79a+, BCL-6+, CD 3-, CD 5-, CD 21-, CD 23-, CD 43-, CD 45RO-, BCL-2-, and Cyclin D1-. Two of the 3 patients exhibited clonal bands for the IgH gene by polymerase chain reaction assay. "Küttner tumor," which is a common fibrosing, chronic inflammatory lesion of the submandibular gland, is sometimes diagnosed as a malignant tumor. This study indicates that this sclerosing variant of follicular lymphoma should be added to the list of different diagnoses for "Küttner tumor."

Massive hyperplasia of marginal zone B-cells with clear cytoplasm in the lymph node: a case report.

An enlarged axillary lymph node from a 63-year-old woman showed proliferating marginal zone B-cells arranged in a vague nodular pattern or in band-forming aggregates throughout the cortex. Marginal zone B-cells, which also infiltrated the adjacent fatty tissue, had round or slightly indented nuclei of medium size and a moderate amount of clear cytoplasm. Immunohistochemically, these cells were CD20+, CD79a+, Bcl-2+, sIgD-, CD5-, CD10-, CD21-, CD23-, CD45RO-, Bcl-6-, and cyclin D-. A portion of the cells were sIgM- and CD43-positive. The polytypic nature of these cells was demonstrated by immunohistochemistry and polymerase chain reaction. Systemic bacterial infection appears to be the cause of marginal zone B-cell hyperplasia. This unusual marginal zone B-cell hyperplasia should be differentiated from low-grade B cell lymphomas, and particularly from nodal marginal zone B-cell lymphomas.

Classical Hodgkin lymphoma occurring in clusters of nodal marginal zone B-lymphocytes in association with progressive transformation of germinal center. A case report.

We present a case of a classical Hodgkin lymphoma occurring in clusters of marginal zone B-lymphocytes (MZBLs). Most lymphoid follicles possessed hyperplastic germinal centers, while a portion of the follicles exhibited a progressive transformation of the germinal center (PTGC). Clusters of MZBLs showed a perifollicular distribution. The classic Reed-Sternberg cells were found in clusters of MZBLs. A portion of the Reed-Sternberg cells were CD15+, CD20+, CD30+, CD79a+, fascin+, vimentin+, EMA-, and bcl-2-. Some Reed-Sternberg cells were surrounded by CD3+ CD45RO+ CD57-rosettes. In situ hybridization studies demonstrated strong expression of EBER in classic Reed-Sternberg cells and their variants. The overall morphological, immunohistological, and EBV findings confirmed that the present case is a classical Hodgkin lymphoma. The MZBLs were CD20+, CD79a+, sIgM+/-, sIgD-, CD5-, CD21-, CD43-, CD45RO-, and Bcl-2-. Some MZBLs had polytypic intracytoplasmic immunoglobulin. Problems arising in the differential diagnosis between lymphocyte-predominant Hodgkin lymphoma and PTGC have been described. An occasional association between MZBLs clusters and PTGC has been reported previously. This case suggests that classical Hodgkin lymphoma should be added to the differential diagnosis of PTGC.

Truncated product of the bifunctional DLST gene involved in biogenesis of the respiratory chain.

Dihydrolipoamide succinyltransferase (DLST) is a subunit enzyme of the alpha-ketoglutarate dehydrogenase complex of the Krebs cycle. While studying how the DLST genotype contributes to the pathogenesis of Alzheimer's disease (AD), we found a novel mRNA that is transcribed starting from intron 7 in the DLST gene. The novel mRNA level in the brain of AD patients was significantly lower than that of controls. The truncated gene product (designated MIRTD) localized to the intermembrane space of mitochondria. To investigate the function of MIRTD, we established human neuroblastoma SH-SY5Y cells expressing a maxizyme, a kind of ribozyme, that specifically digests the MIRTD mRNA. The expression of the maxizyme specifically eliminated the MIRTD protein and the resultant MIRTD-deficient cells exhibited a marked decrease in the amounts of subunits of complexes I and IV of the mitochondrial respiratory chain, resulting in a decline of activity. A pulse-label experiment revealed that the loss of the subunits is a post-translational event. Thus, the DLST gene is bifunctional and MIRTD transcribed from the gene contributes to the biogenesis of the mitochondrial respiratory complexes.

Progressive transformation of germinal centers: a clinicopathological study of 42 Japanese patients.

To clarify the clinicopathological features of progressive transformation of germinal center (PTGC) unrelated to nodular lymphocyte predominant Hodgkin's lymphoma in Japanese patients, we reviewed 42 cases and compared the results with those of the United States and Germany. Our results were similar to theirs, with male predominance (M/F ratio, 3:1) and the presentation of a solitary asymptomatic enlarged lymph node in the head and neck area as the common features. However, in Japan, PTGC occurs more frequently in elderly patients. In this study, 12 (29%) of the patients with PTGC were aged 60 years or more. Thirteen patients (31%) with lymphadenopathy in the neck and head area had developed localized chronic inflammation (chronic sialoadenitis=4, chronic tonsillitis=3, infectious epidermal cyst=2) or an autoimmune disorder (hyperthyroidism=2 and bronchial asthma=2). None of the patients developed a malignant lymphoma during the follow-up period of 5 to 238 months (median 27 months). Histologically, in a single longitudinal section of the lymph node, the PTGC occupied up to 5% of the total follicles in 22 patients, 5-10% in 10, 10-20% in 7, and more than 20% in 3. In 5 (12%) patients, an association with prominent marginal zone hyperplasia was also noted. This study also indicates that nodal involvement by various low-grade B-cell lymphomas exhibiting marginal zone distribution patterns should be considered as a differential diagnosis of PTGC. Moreover, in Japan, PTGC is thought to be involved in the etiology of florid reactive follicular hyperplasia in elderly patients.

Primary pulmonary low-grade marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type with prominent hyalinosis. A case report.

We report a case of primary pulmonary low-grade marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT)-type with prominent sclerosis, which morphologically resembled pulmonary hyalinizing granuloma (PHG) or inflammatory pseudotumor (IPT) of the lung. The patient, a 66-year-old Japanese female with a history of Sjögren's syndrome and primary biliary cirrhosis, presented with a lower left lobe mass 6.8 cm in diameter. Histologically, the lesion is characterized by dense bundles of collagen with scattered plasma cells, mature small lymphocytes, and histiocytes among the collagen bundles. Only the peripheral area of the nodule contained dense lymphoplasmacytoid and histiocytoid infiltrates. A few centrocyte-like cells were obscured by the numerous plasma cells and plasmacytoid cells. In addition, lymphoepithelial lesions and colonalized lymphoid follicles were identified by immunohistochemistry alone. Although PHG and IPT are unlikely to be confused with pulmonary MALT-type lymphomas, the present case suggests that MALT-type lymphoma should be added to the list of differential diagnoses for PHG and IPT.