Multiple enhancing lesions in frontal lobe, basal ganglia and posterior fossa

A 60 y o female, referred for further management with known multiple lesions in brain on previous CT and MRIs. 

MRI study of brain reveals multiple lesions with nodular and multi locular enhancement on post contrast, lesions clustered in right fronto parietal region along sulci and sub cortical white matter, marked peri lesional vasogenic odema, a similar right temporal white matter lesion. Similar right basal ganglia, bilateral thalamic and bilateral dentate nuclei lesions, with odema.
Few were new lesions compared to previous MRI.
On MR Spectroscopy there is raised choline and choline creatinine ratio.
Absent NAA peak.
Clinically : HIV negative. 

Imaging wise DDs given:
Granulomatous lesion_ Tuberculomas.
Toxoplasmosis. 
Lymphoma
Metastasis.

Histopathology report

Specimen         :  Biopsy -? Tumour tissue, frontal lobe (multicentric SOL’s in brain).
Gross Appearance    : The specimen was received in two containers – bearing patient’s name. Both the containers consists of soft-friable fragments of dull grey-tan tissue; each measuring 1.0X0.5X0.3 cm. and 1.0X0.5X0.5 cm. Both the tissues are submitted as entire specimen for processing.  Codes : A and B.
Microscopy        : Sections A and B both show fragmented bits of neoplastic tissue comprising sheets or rather cohesive aggregates of fairly monotonous appearing intermediate sized, round to oval neoplastic lymphoid cells with stippled – vesicular chromatin and scanty eosinophilic cytoplasm. In few foci the neoplastic lymphoid cells show angiotropism with perivascular clustering. Couple of foci show scattered mitosis. No evidence of glial differentiation seen. No granulomas seen.

Diagnosis         : 
Histo pathological features are consistent with “Primary Central Nervous System, Malignant Non-Hodgkin’s Lymphoma – of probable B lineage”

Advsed Immunohistochemical ancillary studies for confirmation and definite lineage typing.