Tuberculosis - The spoil sport

Dear Sir, 
 
This is in response to the article ‘Pictorial essay: PET/CT in tuberculosis’ by Harkirat et al. We could not agree more with the opinion of the authors. When PET/CT is drawing so much attention from the whole medical fraternity, particularly due to its very high sensitivity in cancer staging and re-staging, a very common and old disease called tuberculosis is spoiling the party, especially so in countries like India where the prevalence of tuberculosis is significantly higher than in the West. Tuberculosis frequently masquerades as malignancy and, when extensive, is often mistaken for the same. We wish to share with our colleagues our experience with two such cases, where the clinical suspicion of tuberculosis was not high although the patients were later found to have extensive disease throughout the body.

Tuberculosis -The spoil sport retrocrural lymph nodes.The delayed PET/CT images demonstrated a slight increase in the SUV.A probable diagnosis of lymphoma was considered.Biopsy from a metabolically active retroperitoneal lymph node ruled out lymphoma and conÞ rmed tuberculosis.

Case 2
A 24-year-old male presented with mild diff use skeletal pain.No other systemic symptoms were present.The patient was well built and nourished.An FDG PET/CT scan revealed [Figure 2] metabolically active, extensive skeletal osteolytic lesions in the calvarium, in the vertebral column at multiple levels, including the body and posterior Dear Sir, This is in response to the article 'Pictorial essay: PET/CT in tuberculosis' by Harkirat et al.We could not agree more with the opinion of the authors.When PET/CT is drawing so much attention from the whole medical fraternity, particularly due to its very high sensitivity in cancer staging and re-staging, a very common and old disease called tuberculosis is spoiling the party, especially so in countries like India where the prevalence of tuberculosis is significantly higher than in the West.Tuberculosis frequently masquerades as malignancy and, when extensive, is oft en mistaken for the same.We wish to share with our colleagues our experience with two such cases, where the clinical suspicion of tuberculosis was not high although the patients were later found to have extensive disease throughout the body.

Case 1
A 56-year-old woman presented with ascites and lymphadenopathy, which were suggestive of metastases.An FDG PET/CT scan revealed [Figure 1] metabolically active, extensive lymphadenopathy in the axilla, mediastinum, abdomen, pelvis, and in the inguinal regions; there was also diff use omental thickening with enhancement, a few faintly enhancing peritoneal soft tissues, right pleural eff usion, and ascites.There was a maximum Standard Uptake Value (SUV) of 3.2 in the periportal, perigastric, peripancreatic, retrocaval, and elements and in the sternum, scapulae, ribs, and pelvic bones.A few sclerotic foci were also noted in the T4 and T5 vertebral bodies.No metabolically active lymphadenopathy was identiÞ ed.A large metabolically active soft tissue mass was associated with the sternal lesion.A maximum SUV of 3.7 was seen in some of the skeletal lesions.Multiple metabolically active lung nodules were seen in both upper lobes and in the apical segment of the left lower lobe, with a maximum SUV of 1.5.On delayed images, there was signiÞ cant increase in the SUV value of the majority of the lesions.A working diagnosis of skeletal metastases was considered.Biopsy from the sternal lesion ruled out malignancy and was indicative of tuberculosis.Biopsy from another site (left ilium) conÞ rmed the diagnosis of tuberculosis.
Tuberculosis can have a varied presentation.There are reports of metabolically active breast masses with extensive axillary, cervical, and mediastinal lymphadenopathy that were initially mistaken for breast cancer with extensive lymph nodal metastasis but were later conÞ rmed to be of tuberculous etiology. [1]e above cases demonstrate the inadequacy of PET in the presence of tuberculosis.The associated diagnostic CT scan, though still not very speciÞ c, can be very useful in demonstrating the morphological details, particularly when used with intravenous contrast.Necrotic lymph nodes on contrast-enhanced CT scan (CECT), centrilobular lung nodules on high-resolution CT scan of the lungs, and soft tissue calciÞ cations etc., can help in arriving at a conÞ dent diagnosis of tuberculosis.In high-prevalence geographic regions like India, tuberculous etiology should always be considered in the diff erential diagnoses and must be ruled out before a diagnosis of malignancy is made.
Newer and more speciÞ c radiotracers like positron-emitt er labeled antituberculous drug molecules may help to diff erentiate tuberculosis from cancer and nontuberculous inß ammatory processes in the future. [2] Govindarajan, Nagaraj, Ravikumar, Arjun Kalyanpur, Kallur Bangalore Institute of Oncology-Health Care Global-Bangalore, Teleradiology Solutions, Bangalore, India.E-mail: revathigovind@gmail.comWe have read the article on high-resolution USG of the anterior abdominal wall by Sudheer Gokhale. [1]He has given clear descriptions of almost all the pathologies of the anterior abdominal wall as seen on high-resolution USG.We want to draw att ention to another very important pathology of the anterior abdominal wall that is endemic in our country, which is subcutaneous or intramuscular cysticercosis.High-resolution USG is diagnostic for subcutaneous and intramuscular cysticercosis. [2,3]We have come across two patients with anterior abdominal wall cysticercosis.
The first patient, a 28-year-old man, presented with a swelling on the left side of the anterior abdominal wall that had been present for 1 month.Clinically, it was diagnosed as a lipoma or neuroÞ broma.The patient was sent for a highresolution USG study, which revealed a well-deÞ ned cystic lesion with an echogenic nidus in the subcutaneous tissue in the area of the swelling [Figure 1].Based on these Þ ndings, the diagnosis of subcutaneous cysticercosis was made.