|Ahead of print publication
Primary diffuse large B-cell lymphoma masquerading as uterine fibroid: A pathologists' diagnosis
Aarti Tyagi, Andleeb Abrari, Urmi Mukherjee
Department of Lab Medicine, Max Super Speciality Hospital, New Delhi, India
|Date of Submission||29-Jul-2018|
|Date of Decision||11-Nov-2018|
|Date of Acceptance||16-Jan-2019|
|Date of Web Publication||09-May-2020|
Department of Pathology, Max Super Speciality Hospital, Saket, New Delhi - 110 017
Source of Support: None, Conflict of Interest: None
Lymphoma involving the uterus is rare, and the diagnosis is usually difficult due to the rarity and nonspecific presentation. The treatment is often delayed and difficult because there is no standard treatment. We report our experience with a case of diffuse large B-cell lymphoma (DLBCL) involving the uterus. A 40-year-old female presented to our hospital posthysterectomy for suspected fibroid. Computed tomography scan and the tissue biopsy along with the immunoprofile revealed uterine DLBCL. She was treated with chemotherapy followed by radiation therapy and showed the complete response to the treatment, and thus, the clinicians should be aware of this rare disease for prompt diagnosis.
Keywords: Diffuse large B-cell lymphoma, fibroid, uterus
| > Introduction|| |
Extranodal non-Hodgkin's lymphomas (NHLs) are about 25% of all cases of lymphomas. It can involve almost any organ in the body. The frequently involved system is gastrointestinal tract (stomach being the most common site), followed by Waldeyer's ring, lung, liver, spleen, bone, and skin. Commonly the primary site of origin for lymphomas is lymphoid tissue or the lymph nodes, and approximately 10%–35% of patients have primary extranodal lymphoma at the time of diagnosis. Of these cases, <1% originate in the female genital tract. Even among this extranodal region, uterus is a rare site of involvement. Because of the lack of any specific symptoms, it is not easy to distinguish it from more common neoplasms involving uterus, such as a uterine sarcoma. Diagnosis can be delayed and difficult if not suspected clinically or pathologically. Here, we report our experience with a case of diffuse large B-cell lymphoma (DLBCL) involving the uterus.
| > Case Report|| |
A 40-year-old female presented to our hospital posthysterectomy, operated elsewhere for suspected fibroid with pathology opinion, suggesting epithelioid leiomyosarcoma/leiomyoblastoma. No immunohistochemistry (IHC) had been done outside.
Paraffin blocks and slides were received for review. It was suboptimally processed material, which microscopically revealed benign secretory endometrium, myometrium, and fallopian tube. Some sections represented vascularized fibrous connective tissue with an infiltrate of round, polygonal cells with irregular nuclei and scattered polylobate forms [Figure 1]. Mitoses were frequent. There was no morphological evidence of epithelial/mesenchymal neoplasia.
|Figure 1: Photomicrograph showing an infiltrate of round, polygonal cells with irregular nuclei (H and E, ×400)|
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A rather inclusive panel of IHC was performed (please see below, under tru-cut biopsy). On IHC, these cells were marked diffusely and strongly with CD20 [Figure 2] and LCA. Ki-67 was noncontributory (repeated 3 times). Immunoprofile was consistent with diffuse B-cell NHL.
Bone marrow trephine aspiration and biopsy showed normal morphology with no lymphoma infiltration. Whole-body fluorodeoxyglucose (FDG) positron emission tomography scan showed postoperative changes in the uterus with FDG avid, heterogeneously enhancing soft-tissue mass measuring 3.8 cm × 2.9 cm × 2.7 cm in the operative bed showing indistinct fat planes with urinary bladder [Figure 3].
|Figure 3: Fluorodeoxyglucose positron emission tomography scan pelvis, showing nonfluorodeoxyglucose avid, heterogeneous, soft-tissue mass|
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Tru-cut biopsy of the described mass on microscopic examination showed diffuse stromal infiltration by atypical large lymphoid cells with angulated nuclei, indistinct nucleoli, and scant cytoplasm [Figure 4]. The atypical lymphoid cells expressed CD45, CD20, KI-67 labeling index −80% [Figure 5] and were negative for cyclin D1, Tdt, CD34, SMA, CK, CD10, caldesmon, CD3, CD30, and vimentin. Immunomorphology was compatible with DLBCL.
|Figure 4: Photomicrograph showing atypical large lymphoid cells with angulated nuclei, indistinct nucleoli, and scant cytoplasm with no necrosis, ×400|
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|Figure 5: Photomicrograph showing Ki 67 – immunoreactive in 80% cell population, ×400|
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The patient was treated with chemotherapy followed by radiation therapy and showed complete response to the treatment for over 4 years.
| > Discussion|| |
Even if the uterus is found to be the main clinical lesion site, it is usually difficult to determine whether the uterus is the primary site of involvement or an infiltrative site in an advanced stage of disease. To assess the primacy of a uterine DLBCL, the diagnosis is considered if the disease is confined to the organ and if there are no signs of DLBCL in other organs at diagnosis or during follow-up.
The diagnosis of extralymphatic NHL usually made postoperatively in the surgical specimen because preoperative diagnosis is sometimes difficult. The prognosis is relatively good, and the 5-year survival rate has been reported to be 73%.
The differential diagnosis of indifferent round to polygonal cells, especially at this site, included endometrial stromal sarcoma, undifferentiated carcinoma, neuroendocrine carcinoma, sex cord-stromal tumor, dominant sarcomatoid component of a carcinosarcoma, primitive neuroectodermal tumor, small-cell leiomyosarcoma, melanoma, and anaplastic large-cell lymphoma, monomorphic type. Morphologically, the distinctive infiltrating tongues with perivascular arrangements of stromal sarcoma were not seen; any telltale feature of epithelial differentiation/carcinoma, namely incipient lumens, secretions, syncytia, intercellular junctions, was absent, as was pathognomonic neuroendocrine chromatin. Histologic features typical of sex cord-stromal differentiation, subtle or overt polyphasic carcinosarcoma components, rosettes of primitive neuroectodermal tumor, leiomyoid cells, and melanin pigment were all absent.
In essence, finally, the diagnosis squarely rested on a comprehensive panel of IHC, rather than morphology.
| > Conclusion|| |
Primary uterine NHL being rare, this case of a uterine DLBCL is being reported. This reiterates that unusual morphologies at unusual sites are the more eligible instances, which require comprehensive immunomorphologic review for appropriate management and no diagnosis can be presumptive.
In the present case, tumor was classified as a DLBCL. Diagnosis necessitated diligent morphology review and exhaustive IHC. No other site of origin and no regional or systemic secondary involvement was detected on the imaging and hematologic workup.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]