Role of FDG-PET/CT in detecting lymphomatous bone marrow involvement
in patients with newly diagnosed diffuse large B-cell lymphoma.
It was also recorded whether bone marrow involvement
was present or not at time of diagnosis.
Bone marrow biopsy following lymph node diagnosis of HL confirmed involvement of the bone marrow in 72 patients (23.7%), while 168 patients (55.4%) did not have bone marrow involvement
(Table 1 and Fig.
A special stage, Neuroblastoma Stage 4s (NB4s) has a good prognosis despite disease dissemination, accounting for 7-10% of all NB cases and refers to small primary tumour with infiltration limilted to the skin, liver, and/or marrow.23 The International Neuroblastoma Staging System restricts this diagnosis to children under 1 year at the time of diagnosis and bone marrow involvement
less than 10%, despite the presence of large tumor burden, hallmark of this stage is the possibility of spontaneous regression.24-26 In this study there were two cases of NB4s aged 2 months and 4 months respectively, both had infiltration of skin, liver and bone marrow.
Chen, "Uveal melanoma with diffuse bone marrow involvement
," Blood, vol.
Data describing the frequency of bone marrow involvement
and various patterns of infiltration in Non-Hodgkin lymphoma patients in local population is scarce.
Conventional bone marrow biopsies indicate that about 26-40% of patients with metastatic breast cancer have bone marrow involvements
B-LBL has a much lower incidence (approximately 10% of all LBL), predominates in older age population, and is less likely to present with bone marrow involvement
compared with its T-cell counterpart [2, 3].
However, few authors have mentioned bone marrow involvement
as thymic carcinoma's initial clinical presentation like in the present case [13, 14], and others have identified it during the progression or late stages of the disease  while few speculated it to occur during the tumor recurrence after surgical intervention .
Thrombocytopenia is a frequent finding in patients with cancer and is usually caused by bone marrow involvement
of malignant cells or by toxicity from anticancer therapy.
Wong from Hong Kong reported a case of Sinonasal angiosarcoma with marrow involvement, mimicking malignant lymphoma.5 Chen Wang published another report from University of Toronto with a rare finding of bone marrow involvement
in angiosarcoma of the spleen.6
(7) Recurrent fever in addition to observed pallor, low growth rate, and relevant laboratory results raised the index of suspicion for a neoplastic process with bone marrow involvement