Morphological spectrum of AIDS-related plasmablastic lymphomas.

We have had a recent spurt in cases of AIDS-related lymphoma (ARL) at our centre. Most of these cases are aggressive mature B cell lymphomas, mainly plasmablastic lymphoma (PBL) and diffuse large B-cell lymphoma (DLBCL). Most of the PBL are extranodal in location and are mucosa-based. We reviewed the morphological features of 34 cases of PBL. Diagnosis was based on morphology, immunohistochemistry, proliferation index, HIV positive status and its preference to extranodal sites (mostly mucosa based). We classified PBL into three morphological subtypes (immunoblastic - 25, Burkitt's - 7, plasmacytic - 2). Tumor cells expressed as leucocyte common antigen (LCA) in 60%, CD138 in 100%, EMA in 45% and light chain restriction in 86% cases. CD20 was negative in all cases. Pathologists need to be aware of PBL and its various morphological subtypes as the identification of this entity from its close differentials carries major therapeutic implications.

Solitary fibrous tumour: a diagnostic dilemma.

Solitary fibrous tumour (SFT) is a rare spindle cell neoplasm arising at pleural and extrapleural sites. Five cases of SFT diagnosed at our institution over a five year period were reviewed. Haematoxylin and eosin stained histological sections, immuno-histochemical markers including CD34 and electron microscopy were the different methods used to study these tumours. Three histological features were consistently observed in all the tumours: the tumours were composed of short spindle cells separated by dense collagen bands and arranged in alternate hypocellular and hypercellular areas. CD34 positivity was seen in all the cases. SFT's have been reported to behave in an unpredictable fashion and hence prolonged follow up is essential. Histology, CD34 positivity and electron microscopy are useful tools in diagnosing SFT. While the pleural tumours can be diagnosed based on histology, this must be substantiated by ancillary techniques in case of extrapleural tumours.

Laryngeal chondrometaplasia: a great mimic of chondrosarcoma.

Chondrometaplasia of larynx is a rare entity with an unknown etiopathogenesis. The lesion remains asymptomatic unless it reaches a large size and a history of trauma is usually elicited. It is a known pitfall in diagnostic evaluation and a clinically significant differential considered in evaluation of cartilaginous tumors of the larynx. A 66-year-old man presented with a nodular mass of right side of neck, progressive hoarseness of voice and pain, and a suspicious growth in the right glottic region. A CT followed by an MRI one month later revealed a slow growing ill defined thickening and enhancement of the supraglottic soft tissues, predominantly involving the submucosa, along the greater cornu on the left side of the thyroid cartilage, with extra-chondral enhancement and was suggested to be of infectious etiology. On neck exploration a lesion clinically suspected to be a chondrosarcoma was excised along with the right ala of the thyroid cartilage. The tissue processed entirely, revealed features consistent with chondrometaplasia of larynx. The importance of distinguishing this lesion from cartilaginous tumors is emphasized.

Follicular dendritic cell tumour of tonsil - is it an under-diagnosed entity?

Neoplasms of follicular dendritic cells are uncommon and while majority of them occur in lymph nodes, they are increasingly recognized at varied sites such as abdominal viscera. Tonsil is the most common extra nodal site for occurrence of FDCT in the head and neck region. We describe three cases of follicular dendritic cell tumour occurring in the tonsil.

Borderline epithelial tumours of the ovary--a retrospective analysis of 31 cases.

Thirty one cases of epithelial borderline tumours of the ovary recorded over a period of six years were reviewed. The incidence of borderline tumours was 6% in relation to ovarian epithelial malignancies, with serous and mucinous types comprising three fourth of the lesions. The serous tumours were bilateral in 39%, revealed surface growth in 17% and had peritoneal implants in 11% of cases. The mucinous tumours were bilateral in 11% and had associated pseudomyxoma peritonei in 22% of cases. Nuclear grade appeared to correlate with extraovarian spread and surface growth in the serous borderline tumours, but not in the mucinous borderline tumours. The endometrioid borderline tumours and mixed epithelial borderline tumours were rare lesions. Twenty one patients (68%) presented in Stage-la. Surface growth correlated with recurrences. The prognosis remained good in serous borderline tumours even in the presence of implants as these were non-invasive. The mean disease free survival was 43.03 months. There was no statistical difference in disease free survival of patients with and without implants.