Sarcomatoid variant of anaplastic large cell lymphoma with cytoplasmic ALK and alpha-smooth muscle actin expression: a mimic of inflammatory myofibroblastic tumor

Epithelioid inflammatory myofibroblastic sarcoma: a case report and brief literature review

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare variant of the inflammatory myofibroblastic tumor, characterized by more aggressive clinical course and nuclear membrane staining of anaplastic lymphoma kinase (ALK) with ALK rearrangement. An elderly male came to the clinic because of an accidental abdominal mass. Abdominal and pelvic enhanced CT revealed a tumor apparently orginated from mesenchymal tissue. Subsequently, the abdominal mass and multiple organ resection was performed, and the mass was pathologically confirmed as EIMS. The patient developed Clavien-Dindo Grade III postoperative complications and was discharged after his condition improved. He received doxorubicin monotherapy after operation, but only one cycle was administered due to severe vomiting. The follow-up of 5 months after operation showed no evidence of recurrence. Given the rarity of EIMS, and ALk inhibitors have a long and robust effect on patients with ALK gene tumors, it is very important for clinicians to be familiar with the clinicopathological features of EIMS, which will contribute to the accurate diagnosis of EIMS and reduce misdiagnosis.

Spindle-cell (Sarcomatoid) Variant of Cutaneous Anaplastic Large-cell Lymphoma (C-ALCL): An Unusual Mimicker of Cutaneous Malignant Mesenchymal Tumors-A Series of 11 Cases

Cutaneous anaplastic large-cell lymphoma (C-ALCL) represents one of the entities within the group of CD30-positive lymphoproliferative disorders of the skin. Most cases are ALK-negative, though isolated cases of ALK-positive C-ALCL have also been reported. By definition, the diagnosis of C-ALCL requires the expression of CD30 in >75% of the cells. Histopathologically, C-ALCL shows a dermal-based nodular and circumscribed proliferation of large pleomorphic cells with vesicular nuclei, prominent nucleoli, and eosinophilic cytoplasm, including hallmark cells. Since 1990, isolated case reports of a so-called "sarcomatoid" variant have been published in the literature. Herein, we present a series of 11 cases of spindle (sarcomatoid) C-ALCL, with comprehensive histopathologic, immunophenotypic, and molecular data. Spindle C-ALCL represents a potential mimicker of malignant mesenchymal or hematopoietic tumors in the skin and should always be considered in the differential diagnosis when assessing cutaneous pleomorphic spindle cell neoplasms.

Diagnostic Challenge of Sarcomatoid Variant of ALK-Positive Anaplastic Large Cell Lymphoma: Case Report and Updated Systematic Literature Review

The sarcomatoid variant of anaplastic large cell lymphoma is an extremely rare histologic pattern of anaplastic large cell lymphoma that consists of spindle-shaped neoplastic cells and is easily misdiagnosed as a soft tissue sarcoma. We report a case of the sarcomatoid variant of anaplastic large cell lymphoma that was initially diagnosed as an inflammatory myofibroblastic tumor in our hospital and as liposarcoma after consultation. This article analyzed the features of this entity by reviewing the literature. Only 15 cases have been reported, most of which were misdiagnosed as sarcoma, sarcomatoid carcinoma, or inflammatory myofibroblastic tumor. Most of the reported cases showed a myxoid stroma, with a variable number of inflammatory cells. The hallmark cells usually can be found by careful evaluation of the slides. Immunohistochemistry including CD30, EMA, and ALK are the most useful for diagnosis. Most are III or IV stage, and have a good prognosis after chemotherapy.

Epithelioid Inflammatory Myofibroblastic Sarcoma of the Ovary With RANB2-ALK Fusion: Report of a Case

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a recently described, clinically aggressive variant of inflammatory myofibroblastic tumor with a predilection for intraabdominal sites, tendency to arise in male patients and resistance to conventional chemotherapy and radiotherapy. We present a case of a 15-year-old girl with EIMS of the ovary with a RANBP2-ALK fusion. During 2 years of follow up, she experienced multiple recurrences. Following classification of the tumor as EIMS, the patient began treatment with an ALK inhibitor (crizotinib), which led to disease improvement within weeks of administration. To the best of our knowledge, this represents the first reported case of EIMS arising in the female genital tract.

Epithelioid inflammatory myofibroblastic sarcoma: a clinicopathological, immunohistochemical and molecular cytogenetic analysis of five additional cases and review of the literature

Background

To explore the clinical characteristics and pathological features of epithelioid inflammatory myofibroblastic sarcoma (EIMS) with emphasis on the diagnostic spectrum.

Methods

The clinical data and histological features in 5 additional cases of EIMS were retrospectively reviewed. Immunohistochemical study and interphase fluorescence in situ hybridization (FISH) analysis were carried out.

Results

There were 2 males and 3 females with age at presentation ranging from 15 to 58 years (mean, 37 years). All 5 tumors were intra-abdominal with 2 arising in the mesentery and 1 each in the omentum, rectum and transverse colon. The tumor size ranged from 5 to 20 cm in maximum diameter (mean, 10.7 cm). Histologically, all 5 tumors were composed predominantly of large epithelioid cells possessing vesicular nuclei, prominent nucleoli, and amphophilic cytoplasm. Mitotic figures were easily identified (mean, 20/10HPF). Tumor cells were arranged in clusters or sheets embedded in a myxoid stroma containing prominent neutrophils. A minor component of spindle cells was present in focal areas. By immunohistochemistry, all 5 cases were positive for anaplastic lymphoma kinase (ALK) with a nuclear membrane pattern in 4 and cytoplasmic staining with perinuclear accentuation in 1. Besides ALK, tumor cells stained variably for desmin (4/5), alpha smooth muscle actin (2/5), muscle-specific actin (1/2) and pan-cytokeratin (1/4). FISH analysis demonstrated the presence of ALK rearrangement in all 5 cases. Of 5 patients, 3 developed local recurrence, 1 died of disease 8 months after surgery.

Conclusion

EIMS represents a highly aggressive variant of inflammatory myofibroblastic tumor characterized by epithelioid morphology, prominent neutrophilic infiltrate, and nuclear membrane staining of ALK with ALK rearrangement. As patients with ALK-rearrangement tumors may benefit from targeted therapy, accurate diagnosis of EIMS is very important. Familiar with the characteristic features of EIMS will help pathologists avoid misdiagnosing the tumor as other malignancies.

Pulmonary epithelioid inflammatory myofibroblastic sarcoma with multiple bone metastases: case report and review of literature

Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is a rare variant of inflammatory myofibroblastic tumor with distinctive morphological features and malignant clinical behavior. Only a few such cases have been described in the literature. We report here a case of unusual pulmonary EIMS with multiple bone metastases. A 21-year-old Chinese male patient presented with complaints of general fatigue and rapid weight loss, and a huge tumor arising in the left lower lobe of lung was detected by chest computed tomography. The mass of lung was totally resected. Microscopically, the tumor cells were rounded and epithelioid in shape. Myxoid stroma and inflammatory infiltration was also present. The tumor cells were immunopositive to anaplastic lymphoma kinase (ALK) in smooth cytoplasmic pattern. Fluorescence in situ hybridization (FISH) assay revealed the presence of rearrangement of ALK gene. Three months after lung surgery, there were multiple bone metastases and intraspinal mass found by positron emission tomography. The second surgical treatment was performed to remove the intraspinal lesion. The histological and immunohistochemical features of intraspinal mass were similar to those of pulmonary tumor. The diagnosis of pulmonary EIMS with multiple bone metastases was made. To the best of our knowledge, it may be the first case of an EIMS arising in lung. Awareness of EIMS in respiratory tract and its distinctive features is important for pathologists to avoid a diagnostic pitfall caused by histologic similarities to other ALK-positive tumors. ALK inhibitor is a promising treatment for this aggressive tumor regardless of its potential acquired resistance.

ALK-positive anaplastic large cell lymphoma with an unusual alveolar growth pattern

Anaplastic large cell lymphoma (ALCL) possesses a broad morphological spectrum. Currently, we present a case of ALK-positive ALCL presenting with an alveolar growth pattern in a 22-year-old Chinese female. This patient complained of a progressively enlarged mass in the right axillary region for 6 months. Excisional biopsy revealed a well-developed alveolar structure with nests of dyscohesive tumor cells separated by delicate fibrovascular septae. The large pleomorphic cells have irregular nuclei with prominent nucleoli and fine chromatin and abundant pale cytoplasm. The neoplasm stained positively for CD2, CD3ε, CD30, ALK1, EMA and cytotoxic molecules (TIA1 and Granzyme B). Cytogenetic study via interphase Fluorescence in-Situ Hybridization disclosed the rearrangement involving ALK gene. The patient received 6 cycles of CHOP chemotherapy and achieved complete remission. She is alive in good condition up to the present. Our case is biologically similar to the conventional ALK-positive ALCLs and may just represent an unusual morphological appearance.

Sarcomatoid variant of ALK- anaplastic large cell lymphoma involving multiple lymph nodes and both lungs with production of proinflammatory cytokines: report of a case and review of literature

Sarcomatoid variant of anaplastic large cell lymphoma (ALCL) is one of the rarest histologic variants of ALCL that consists of large, bizarre, often spindle-shaped, neoplastic cells resembling a soft tissue sarcoma. We report here such a case of ALCL with both pulmonary and multiple nodal involvement in a 47-year-old woman who initially presented with fever, cough, sputum, itching skin, and weight loss. The initial transbronchial lung biopsy showed discohesive pleomorphic malignant cells in a strong inflammatory milieu reminiscent of inflammatory malignant fibrous histiocytoma (MFH). Subsequent cervical lymph node biopsy revealed a spindle cell sarcoma predominantly composed of plump spindle and oval neoplastic cells in interweaving fascicles, with sparse inflammatory infiltrates, resembling pleomorphic-storiform type of MFH. However, these tumor cells in the lung and node lesions revealed essentially similar immunohistochemical features that were positive for CD30, EMA, TIA-1, granzyme B, and fascin, but negative for anaplastic lymphoma kinase (ALK), and T- or B-lineage-specific marker. The spindled cells stains diffuse strong positive for smooth muscle actin (SMA), along with vimentin. Further studies showed that the tumor produced large quantities of the proinflammatory cytokines interleukin-2 (IL-2), IL-6, and IL-8, which we believe may contribute to the pathogenesis of sarcomatoid transformation of this tumor, and was associated with the patient's inflammatory symptoms. To the best of our knowledge, this is the first reported case of sarcomatoid variant of ALK-negative ALCL with null cell phenotype and in situ production of proinflammatory cytokines presenting as multiple nodes and pulmonary involvement.

A spindle cell variant of diffuse large B-cell lymphoma is characterized by T-cell/myofibrohistio-rich stromal alterations: analysis of 10 cases and a review of the literature

Spindle-shaped diffuse large B-cell lymphoma (Sp-DLBCL) has been recognized as a rare morphologic variant of DLBCL. However, the biological processes that contribute to the specific features of Sp-DLBCL remain poorly understood. In this study, a combined immunophenotypic and genetic analysis was performed in 10 Sp-DLBCL. First, we investigated several unique markers for anaplasia (CD30, ALK, CD68, and EBER-ISH), mesenchyma (SMA, desmin, and vimentin), and B-cell differentiation (CD10, BCL6, and MUM1). We also performed conventional cytogenetic and fluorescence in situ hybridization studies to look for common chromosomal break points (BCL2, BCL6, and MYC). We found that most Sp-DLBCLs were germinal center B cell-like and that none had any other specific phenotypes or any karyotypic abnormalities. Instead, T cells, CD68-positive macrophages and SMA-positive myofibroblasts were significantly increased in Sp-DLBCL when compared with conventional GCB origin DLBCL cases (n = 10) (P = 0.012, P < 0.001, and P < 0.0001, respectively). To further characterize Sp-DLBCL, we next compared the expression of fibroblast growth factor 2 (FGF2) and transforming growth factor-β1 (TGFβ1) between the two types of DLBCL. Finally, we confirmed that the number of FGF2- and TGFβ1-positive stromal cells was markedly increased in Sp-DLBCL and that the difference between these and conventional GCB origin DLBCLs was significant (P < 0.0001 and P = 0.0017, respectively). Thus, T-cell/myofibrohistio-rich stromal alterations in Sp-DLBCL, especially those mediated by TGFβ1 and FGF2, may play a role in the transition of lymphoma cells into those with spindle-shaped features.

ALK-positive anaplastic large-cell lymphoma: strong T and B anti-tumour responses may cause hypocellular aspects of lymph nodes mimicking inflammatory lesions

The anaplastic large cell lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) is a rare type of non-Hodgkin lymphoma which occurs in children mostly. The ALK protein is highly immunogenic and elicits both humoral and cellular immune responses. A 15-yr-old child presented with fever and adenopathy and did not respond to antibiotics. Biopsy of the enlarged lymph node contained almost no lymphoid element except for a few CD8-positive T cells, plasma cells and isolated CD30-positive blasts. The patient's condition improved following lymphadenectomy but relapse occurred 3 months later with multiple nodes, high fever and an abdominal mass. This time an ALK-positive ALCL was diagnosed and the retrospective analysis of the initial biopsy revealed rare, isolated ALK+ cells. Molecular analysis showed T-cell clones and oligoclonal B cells in both biopsies and peripheral blood of the patient. The tumour cells harbour a t(2;5) translocation, revealing a null phenotype by immunohistochemistry and no evidence for T-cell clonality by Southern blotting. The patient's serum contained anti-ALK antibodies. Our findings suggest that the T-cell clones and anti-ALK antibodies in this patient constitute an anti-tumour response that caused the hypocellularity of the initial lymph node. Hypocellular and oedematous lymph nodes occurring in a child with evocative symptoms should be tested for the presence of ALK.

p53 Mutation and MDM2 amplification in inflammatory myofibroblastic tumours

AIMS

The pathogenic mechanism and predictive indicators of biological behaviour of inflammatory myofibroblastic tumour are poorly understood. We investigated molecular abnormalities of p53 and MDM2 in order to assess whether these play an important role in pathogenesis, and whether they also contribute to clinicopathological aggressive phenotype in inflammatory myofibroblastic tumour.

METHODS AND RESULTS

We compared the immunohistochemical expression of calponin, h-caldesmon, ALK, and p53 gene mutation and MDM2 gene amplification with clinicopathological findings in 15 cases of inflammatory myofibroblastic tumour. Histologically, cellular atypia was observed in five (33.3%) out of 15 cases. Local recurrences were observed in two (14.3%) of 14 informative cases, but no distant metastasis was observed. The expression of calponin (9/14; 64%) but not h-caldesmon (0/14; 0%) was seen, which suggested myofibroblastic differentiation. ALK expression was seen in eight (53.3%) out of 15 cases, particularly in patients under 40 years old. Nuclear expression of p53 protein was recognized in only one (6.7%) of 15 cases, and polymerase chain reaction single-strand conformation polymorphism followed by direct sequencing revealed p53 gene missense mutations in two (13.3%) of 15 cases. Nuclear expression of MDM2 was seen in four (26.7%) of 15 cases, and the MDM2 gene amplification was observed in two of the four cases.

CONCLUSION

Inflammatory myofibroblastic tumour shows a wide spectrum of cellular atypia and biological behaviour with p53 and MDM2 expression. However, the alterations in the p53 pathway seem not to play a major role in the pathogenesis of inflammatory myofibroblastic tumour.

Sarcomatoid variant of anaplastic large cell lymphoma mimicking a primary breast cancer: a challenging diagnosis

The sarcomatoid variant of anaplastic large cell lymphoma is one of the rarest histologic variants of this neoplasm. Due to its sarcomatoid features, it is frequently misdiagnosed as a poorly differentiated sarcoma, anaplastic carcinoma, or melanoma. We report the case of a 92-year-old woman with a sarcomatoid anaplastic large cell lymphoma mimicking a primary breast neoplasm. The patient presented with a rapidly enlarging lump in the left breast and nodules in the right axilla. The immunohistochemical profile showed reactivity for leukocyte common antigen, UCHL-1, vimentin, and CD30, but immunoexpression of anaplastic lymphoma kinase was lacking. Anaplastic large cell lymphomas are lymphoid neoplasms of T-cell/null-cell lineage that consistently express the activation marker CD30 and usually carry a gene rearrangement of the anaplastic lymphoma kinase gene. To the best of our knowledge, this is the first reported case of sarcomatoid anaplastic large cell lymphoma presenting as a primary breast neoplasm in which anaplastic lymphoma kinase expression was assessed.