Discussion

Abdominal symptoms are most common complaint of HIV patients. Precise diagnosis based on symptoms alone is very difficult. Hence radiological investigations especially USG plays significant role in reaching diagnosis [3].

Hepatomegaly was most common finding in our study, As 33 patients out of 60 were having Hepatomegaly with or without fatty infiltration and were having other sonological findings also. 14 pts were having fatty infiltration and one was having hepatic abscess.

Fatty infiltration was observed as increased parenchymal echogenicity (Figure 1a and 1b).

Figure 1: a: Fatty infiltration with rt pleural effusion. b: Fatty infiltration with increased parenchymal echogenicity.

Also there was large association of deranged liver functions and altered echotexture in patients of hepatitis B and C [4]. Among the tumors, there are cases reported of Lymphoma and HCC involving Liver In patients of AIDS. Due to HAART therapy which has prolonged life span of HIV patients there is hepatomegaly with deranged liver function test. Liver echotexture may be coarse with granulomas.

Lymphadenopathy was second most common finding due to compromised immune status [5]. We have found 28 patients with enlarge lymph nodes. The criteria of enlarge node was short axis diameter 10mm or more. Enlarge nodes were round or oval. They were found at Peripancreatic region (Figure 2a), Porta (Figure 2b), Paraaortic region, Mesenteric or in right iliac fossa (Figure 2c). Sonologically enlarge nodes with central echogenic hilum with increased vascularity was seen in cases of adenitis.

Figure 2: a: Enlarged conglomerated peripancreatic nodes. b: Enlarged periportal nodes. c: Anechoic oval enlarged mesenteric lymph nodes.

In patients of tuberculosis nodes were hypoechoic or anechoic having central Caseation. Nodes were scanned with convex and high frequency probes both. Color Doppler was used to see vascularity of nodes.

Splenomegalies found in 18 cases with or without hepatomegaly with or without enlarge nodes. In 6 cases there were abscesses in splenic parenchyma (Figure 3a and b, 3c). In 5 cases abscesses were small 2-10 mm in size and they were multiple in most of cases, in one abscess was of size 18mm. Splenic parenchyma was homogenous. These microabscesses were mostly due to disseminated tuberculosis [6,7]. They were appreciated properly with high frequency probe as hypo/anechoic small nodules. The larger lesion was due to other opportunistic/fungal as correlated with lab reports.

Figure 3: a and b: Splenomegaly with multiple splenic abscesses. c: Multiple small anechoic splenic abscesses.

These lesions can be differentiated with from splenic infiltration by lymphoma in which appearance is more hetrogenous and sometimes cystic [1]. Splenomegaly was found associated with other abdominal findings like enlarge lymph nodes, ascites and hepatomegaly etc.

Ascites was found in 12 cases; in 6 cases it was associated with septations.

Ascitic fluid was having low level echoes. Ascites is commonly seen in patients of tuberculosis it can be septated ascites or non septated [8]. In our study were having pleural effusion also. Hypoproteinemia is another common cause of ascites as these patients are immunocompromised.

Bowel thickening the typical sonographic appearance of the normal bowel wall consists of five concentric, alternately echogenic and hypoechoic layers that we describe from the lumen outward [9]. A small echogenic layer is seen that reflects the superficial mucosal interface. The deep mucosa, including the muscularis mucosa, is seen as a second hyperechoic layer. A third hyperechoic layer is produced by the submucosa and the muscularis propria interface. The muscularis propria is seen as a fourth hypoechoic layer. Finally, the marginal interface to the serosa is seen as the fifth small hyperechoic layer. The average thickness of the normal gut wall i.e., 2 - 4 mm Bowel wall thickening can be tubercular Non tubercular [9]. There can be loss of haustration.

Most common cause of bowel involvement is tuberculosis. Risk of tuberculosis with CD₄ count is less than 100 and with WHO stage 3 is significantly high. Impaired TH 1-type immune response in HIV/AIDS patient makes them prone for tuberculosis.

Tubercular abdominal manifestations can be enlarging nodes/adenitis, Ascites, Splenic abscesses, hepatitis, hepatomegaly renal abscesses bowel thickening and bowel obstruction tubo-ovarian masses and salpingitis [10]. Ascites may be associated with incomplete and complete septations.

Here we have found 4 cases of bowel thickening having tubercular etiology. Bowel thickening of terminal ileum, caecum and IC junction was found in 4 cases with fat stranding and enlarges lymph nodes (Figure 4a and 4b). It was long segment involvement of all the 5 layers of bowel with asymmetrical and circumferential thickening (Figure 1b). In the case of NHL it was short segment involvement of small bowelileum and IC junction with thickened all layers of bowel appearing hypoechoic. In this case there was thickening of ascending colon and transverse colon also as shown in Figure 4c. May be it was reactive thickening or due to some other opportunistic infection associated. As mentioned in literature in CMV infection bowel may be thickened in the region of ascending colon and caecum [9]. Other Associated findings were Hepatosplenomegaly and enlarge lymph nodes.

Figure 4: a): Thickened hypoechoic ileocaecal wall involving. b: Thickened bowel wall in transverse section all the layers of bowel wall. c: Thickenned ascending and transverse colon.

Reactive bowel thickening is also seen in HIV patients due to hypoproteinemia which is often remains underreported.

Non tubercular causes of bowel thickening are inflammatory response or could be due to HIV acquired neoplasia. There is large association with falling CD₄ count. Tumors affecting HIV pts can be classified ad AIDS Defining Cancers ADC and NON AIDS Defining Cancers. AIDS Defining cancers are NHL, Kaposi sarcoma, hepatocellular carcinoma and Cervical Cancers. Non AIDS defining cancers are Lung and Breast cancers [1].

NHL associated with AIDS bears poor prognosis. It may involve several organs in abdomen like spleen, liver, kidneys and retro and intraperitoneal nodes. In Liver and spleen NHL manifest as multiple hypo or hypoechoic masses. NHL has some male predominance.

CD₄ count can be correlated as [8] -

<350 cells /micron L -Kaposi Sarcoma,

<200 Cells /micron L-NHL

<100 cells /micron L -C M V Infection

Kaposi Sarcoma may involve small and large intestine, stomach, liver or genitourinary system. Though we could make out changes in bowel as described still CT can better delineate bowel pathologies.

There can be pancreaticobiliary manifestations in patients of HIV such as GB wall thickening, bulky pancreas dilated MPD [11]. Gall Bladder pathology like thickened GB wall was found in 4 cases. In two of them it was acalculous cholecystitis and in another two there were gall bladder calculi. Though GB calculus are not so common in HIV patients.

Bulky Pancreas found in Two cases in one there was dilated MPD as 5mm (Figure 5). In the second case of bulky pancreas, there was increased AP diameter of 4 and body 3.2cms. There were enlarged peri pancreatic nodes.

Figure 5: Bulky pancreas with dilated MPD 5mm.

There were two case of Cervicitis with fluid in POD. In one there were nabothian cysts also.

Two cases were of testicular abscess having other abdominal findings of enlarge retroperitoneal nodes also. Presented with hypoechoic area in testicular parenchyma with thickened wall of scrotal wall (Figure 6). There was hyperemia in surrounding parenchyma of testis. In one case there was thickened spermatic cord as well. Inguinal lymph nodes were enlarged in both cases along with abdominal nodes. One of them diagnosed as of tubercular etiology. Another was undetermined.

Figure 6: Hypoechoic Testicular abscess a and b with reactive hyperemia b with thickened scrotal wall.

Renal findings in HIV patients are diverse such as Medical renal disease, Pyelonephritis or focal renal masses [12,13]. We could find two cases with renal findings. In our study most common presentation was Renomegaly with increased echogenicity of both cortex and medulla consistent with renal parenchymal disease. There were increased creatinine and urea levels [14].

There can be focal masses in renal parenchyma in cases of abscess long with nephromegaly. Lymphoma may show diffuse bulky kidneys [9,10].

One patient showed pyelonephritis with reduced parenchymal echogenicity. Low level echoes were seen in pelvicalyceal system along with thickened urinary bladder wall > 6mm and moving echoes s/o cystitis.