PRIMARY RENAL LYMPHOMA: A RARE CASE REPORT

Primary renal non-hodgkin lymphoma: a rare case report

Mukesh Kumar, Paramjeet Kaur, Yashpal Verma, Anil Khurana, Nupur Bansal, Ashok K. Chauhan

Department of Radiotherapy, PGIMS (UHS) Rohtak, India

Abstract: Primary renal Non-hodgkin lymphoma is rare. Most of the cases are unilateral though bilateral cases have been reported. Extrarenal involvement is to be excluded by imaging/ staging laprotomy for definitive diagnosis. We are presenting a case of 40-year-old Indian female who was attended with history of right flank pain for 3 years, found to have right renal mass on CT scan, underwent right radical nephrectomy and six courses of chemotherapy with CHOP (Cyclophosphamide, Doxorubicin, Vincristine, Prednisolone) regimen subsequent to histo-pathological confirmation. Patient is asymptomatic on follow up of 18 months.

Keywords:

Chemotherapy, NHL, Lymphoma, PRL, Rare, Renal

Introduction

Malignant lymphoma, especially non-hodgkin lymphoma (NHL), may arise in tissues with no infiltration of the lymphnodes, spleen, Waldeyer’s ring, or thymus; such cases are referred to as primary extranodal NHL. This accounts for one third of all NHL cases.¹ Diffuse large B-cell lymphoma (DLBCL) is the predominant type of NHL, accounting for approximately 40% of all lymphomas.^2,3 It has also been reported that 30-50% of NHL cases have extranodal manifestations in various organs, such as the gastric tract, skin, bone, central nervous system, breast, heart, liver or adrenal glands.¹ Although renal involvement is a common finding in the patients with advanced stages of NHL (ranging from 37 to 47%), primary renal lymphoma (PRL) is quite rare (less than 1 percent of renal lesions) and it is often mistaken for renal cell carcinoma (RCC).⁴ PRL is thought to originate in the lymph node/s of the renal sinus or in the lymphatic network of the renal capsule and to manifest as focal mass/es (solitary or multiple), large infiltrative lesions engulfing the kidney, or diffuse bilateral enlarged kidneys.^5,6 Most patients additionally have adjacent retroperitoneal adenopathy. Currently, more than 50 cases have been reported in the literature.

Case Presentation

This 40-years-old female from Haryana (India) presented with history of pain in abdomen for 3 years which was episodic, vague, relieved by painkillers. She noticed weight loss of approximately 5 kg over past 2 months. On physical examination right flank mass approximately 7cm x 8 cm was palpable.

Blood counts, liver and kidney function tests were within normal limits, whereas urinary analysis showed microhaematuria and proteinuria. Ultrasonography (USG) of the abdomen and pelvis showed an irregular outlined hypoechoic mass lesion of size 8cm x 10cm at the upper pole of right kidney. The contralateral kidney appeared to be normal in size, shape and echotexture.

CECT abdomen and pelvis (Figure 1 A-C) revealed heterogeneously enhancing space occupying lesion on the antero-superior pole of right kidney, extending into suprarenal fossa and abutting inferior hepatic margin. Margin of lesion were poorly circumscribed exophytic. Adrenal gland was not separately visualized from mass. Soft tissue plane with hepatic margin were indistinct and lesion was reaching upto the hilum compressing IVC, encasing renal vascular pedicle, both renal artery and vein.

IVP showed bilateral normal functioning kidney. FNAC of renal mass was suggestive of malignant round cell tumor.

Nephrectomy was done for diagnosis of renal mass. Biopsy was suggestive of NHL, diffuse large B-cell type. Immunohistochemistry was done and showed LCA +, CD20+ and CK, Vimentin & CD5 negative (Figure 2A-D).

Figure 2 A. Photomicrograph showing atypical lymphoid cells diffusely infiltrating renal parenchyma (H & E, 10X)

Figure 2 B. Lymphoid cells positive for LCA (IHC, 20X)

Figure 2C. Lymphoid cells positive for CD20 (IHC, 20X)Figure 2 D. Lymphoid cells negative for CD5 (IHC, 20X)

Physical examination and imaging showed no disease elsewhere in the body. After radical nephrectomy patient was given six cycle of chemotherapy (CHOP) cycle being three weekly (Inj. Cyclophosphamide 750mg/m² D1, Inj. Doxorubicin 50mg/m² D1, Inj. Vincristine 1.4mg m² D1 and Tablet Prednisolone 100 mg PO D1-D4). Rituximab could not be offered due to economical constraints.

Post-chemotherapy ¹⁸F-FDG whole body PET-CT showed no definitive evidence of metabolically active disease anywhere in body (Figure 3). Patient remains symptom-free as of now (18 months after chemotherapy).

Figure 3 PET-CT showing no definite evidence of metabolically active disease

DISCUSSION

The term ‘Primary renal lymphoma’ (PRL) is attributed when the disease is localized to the kidney without any sign of other organ involvement or in which renal involvement is the presenting manifestation.⁷ PRL is a rare and uncertain entity because renal parenchyma lacks lymphatic tissue. Therefore, the status of PRL as a primary disease or the first manifestation of a rapidly progressive systemic disease is controversial.

PRL is often mistaken for a RCC and the diagnosis is performed after a radical nephrectomy. However, imaging studies may

provide evidence for suspected cases of PRL. Ultrasonographic images typically depict an unspecific homogeneous hypoechoic mass. Therefore a CT scan is preferred to differentiate PRL from RCC. PRL usually appears as hypervascularized mass with minimal and characteristic homogeneous contrast enhancement. Other indirect signs of PRL include- renal size enlargement, sinus or hilum direct infiltration by a bulky mass, or diffuse retroperitoneal infiltration. In contrast, indirect signs that may indicate RCC include- presence of calcifications, venous thrombosis, or an obstructive mass effect over the renal vessels or urinary tract. However, a percutaneous biopsy can confirm the diagnosis. Bone gammagraphy and a bone marrow biopsy should be performed to exclude extrarenal dissemination.

Systemic chemotherapy is currently the first treatment option for PRL. Though most authors believe that CHOP protocol should be an elective option (as it is in non-Hodgkin’s BCL), there is no agreed-upon standard treatment approach for PRL. Evidence supporting the efficacy of a combined CHOP + Rituximab protocol compared with CHOP alone in the treatment of DLBCL has been well documented. A recent retrospective study compared both regimens and demonstrated that PFS and OS rates at 2 years after diagnosis were significantly higher for patients in the chemotherapy + Rituximab group (PFS 56%; OS 66%) compared with patients in the chemotherapy alone group (PFS 27%; OS 46%).⁸

PRL has a poor prognosis with rapid dissemination and a 75% mortality rate one year after diagnosis. However, this patient is symptom-free with no evidence of metabolically active disease as of now (18 months follow up). Therefore, we hypothesize that early diagnosis and intervention (excision combined with chemotherapy + rituximab) could improve survival. For its known aggressive nature, close follow up is essential to determine recurrence.

REFERENCES

1. Airaghi L, Greco I, Carrabba M. Unusual presentation of large B cell lymphoma: a case report and review of literature. Clin and Lab Haematol. 2006; 28:338-42.
2. Economopoulos T, Papageorgiou S, Dimopoulos MA. Non-Hodgkin’s lymphomas in Greece according to the WHO classification of lymphoid neoplasms. A retrospective analysis of 810 cases. Acta Haematol. 2005; 113:97-103.
3. Krol AD, le Cessie S, Snijder S, Kluin-Nelemans JC, Kluin PM, Noordijk EM. Non-Hodgkin’s lymphoma in the Netherlands: results from a population-based registry. Leuke Lymphoma. 2003; 44:451-8.
4. Okuno SH, Hoyer JD, Ristow K, Witzig TE. Primary renal non-Hodgkin’s lymphoma. An unusual extranodal site. Cancer. 1995; 75:2258-61.
5. Torrecilla Garcia-Ripoll JR, Pascual Samaniego M, Martin Blanco S, Rivera Ferro J, Peral Martinez JI, Fernandez del Busto E. Primary renal lymphoma. Actas Urol Esp. 2003; 27:555-8.
6. Ganeshan D, Iyer R, Devine C, Bhosale P, Paulson E. Imaging of primary and secondary renal lymphoma. Am J Roentgenol. 2013; 201:712-9.
7. Okuno SH, Hoyer JD, Ristow K, Witzig TE. Primary renal non-Hodgkin's lymphoma. An unusual extranodal site. Cancer. 1995; 75:2258-61.
8. Shimada K, Matsue K, Yamamoto K. Retrospective analysis of intravascular large B-cell lymphoma treated with rituximab-containing chemotherapy as reported by the IVL Study Group in Japan. J Clin Oncol. 2008; 26: 3189-95.