Malignant small round cell tumors [MSRTC] is a term used for tumors composed of malignant round cells that are slightly larger or double the size of red blood cells in air dried smears [1].They generally include Ewing's sarcoma [EWS], peripheral neuro-ectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, retinoblastoma, neuroblastoma, hepatoblastoma, and nephroblastoma [2]. These are difficult to diagnose due to their undifferentiated or primitive character [3]. Here the author presents a case of a child with malignant small round cells tumor who had a close contact with MDR tuberculosis and had taken ATT prophylaxis

A 3 years old male child was referred from a peripheral institute with history of contact to MDR TB 1.5 years back received ATT prophylaxis [Isoniazid and Rifampicin] for 6 months] with history of exposure to cattle presented to a tertiary care centre with prolonged febrile illness of one and half month with significant weight loss 4.7 kg during the illness. He had loss of appetite, painful oral ulcer on day 10-12 of illness. He had dryness and cracking of lips and a history of enlargement of the lymph nodes of the neck. He had pain in both lower limbs for the last 15-20 days which was relieved by massage and compression of limbs. He had no cough, headache, earache, ear discharge, pain abdomen, frequent and burning micturition, loose stool, vomiting, distension of abdomen, joint pain, swelling joint, paucity of limb movement, progressive pallor, bleeding from any site, skin rashes. On examination he had hypertension without any significant difference in the 4 limb blood pressure, wasting, pallor and cardiomegaly with palpable cervical, axillary and inguinal lymph nodes. Possibilities of disseminated TB/ malignancies/ vasculitis/ HIV infection were kept. Striking finding was persistent hypertension, so a possibility of vasculitis [infective/inflammatory] was also considered.  His investigations revealed microcytic hypochromic anemia, raised ESR and CRP. Biochemical profile was normal. USG abdomen showed multiple mesenteric lymph nodes, USG KUB Doppler was normal. Workup for infective causes like brucella/enteric/malaria came out negative. HIV serology was non-reactive. Considering a strong possibility of tuberculosis, multiple gastric lavage for AFB, Mantoux, Gene Xpert were done which were negative for tuberculosis. A thoraco-abdominal CT with angiography was done which showed multiple mediastinal and abdominal lymphadenopathy with central necrosis and calcification. Angiography showed compression of abdominal aorta and left renal artery due to adjacent lymph nodes[the possible cause for hypertension]. 

USG guided FNAC of abdominal lymph nodes was performed which showed features of malignant small blue round cell tumour.Parents were counseled regarding need for further testing for confirmation of diagnosis, TB workup, and need for therapy. However, they want to take a second opinion and want to continue treatment elsewhere. Hence, the patient was discharged on request. He remained hemodynamically stable throughout the hospital stay.

Malignant small round cells tumors [MSRTC] is a group of tumors composed of malignant round cells [1].These malignancies present with constitutional symptoms like fever, unexplained weight loss, loss of appetite. There can be enlarged lymph nodes and palpable lumps. The case discussed presented with similar constitutional symptoms. There was diagnostic challengeas the case was a contact of multidrug resistant tuberculosis in a low income country where clinicians are bound to think in the line of disseminated tuberculosis in such cases. But extensive workup ruled out the possibility of tuberculosis and further the diagnosis of the malignant small blue round cell tumor was established on USG guided FNAC. The exact categorization of these group of tumors require immune-histochemistry and immunophenotyping by flow cytometry, reverse transcriptase polymerase chain reaction [RT-PCR], fluorescence in situ hybridization [FISH], and electron microscopy [3, 4].Treatment is multimodal including surgical resection, chemotherapy and radiotherapy with rehabilitation depending upon the size of tumors, location and type of tumors, but prognosis is poor [5].

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee of Regional Hospital, Himachal Pradesh.

1. Kocjan, Gabrijela. "Diagnostic Dilemmas in FNAC Cytology: Small Round Cell Tumours." Fine Needle Aspiration Cytology: Diagnostic Principles and Dilemmas, 2006, pp. 133-150. SpringerLink, https://link.springer.com/chapter/10.1007/3-540-31412-1_7.

2. Akhtar, Mohammed, et al. "Fine‐Needle Aspiration Biopsy Diagnosis of Small Round Cell Tumors of Childhood: A Comprehensive Approach." Diagnostic Cytopathology, vol. 21, no. 2, 1999, pp. 81-91. Wiley Online Library, https://doi.org/10.1002/(SICI)1097-0339(199908)21:2%3C81::AID-DC2%3E3.0.CO;2-A.

3. Yamazaki, Takamasa, et al. "Peripheral Primitive Neuroectodermal Tumor of the Jugular Foramen: Case Report." Neurosurgery, vol. 51, no. 5, 2002, pp. 1286-1289. Lippincott Williams & Wilkins, https://journals.lww.com/neurosurgery/fulltext/2002/11000/Peripheral_Primitive_Neuroectodermal_Tumor_of_the.28.aspx.

4. Akhtar, Mohammed, et al. "Fine‐Needle Aspiration Biopsy Diagnosis of Round Cell Malignant Tumors of Childhood: A Combined Light and Electron Microscopic Approach." Cancer, vol. 55, no. 8, 1985, pp. 1805-1817. Wiley Online Library, https://doi.org/10.1002/1097-0142(19850415)55:8%3C1805::AID-CNCR2820550828%3E3.0.CO;2.

5. Eralp, Yesim, et al. "Prognostic Factors and Survival in Late Adolescent and Adult Patients with Small Round Cell Tumors." American Journal of Clinical Oncology, vol. 25, no. 4, 2002, pp. 418-424. Lippincott Williams & Wilkins, https://journals.lww.com/amjclinicaloncology/fulltext/2002/08000/prognostic_factors_and_survival_in_late_adolescent.20.aspx.