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The Carotid Conundrum: Unraveling Splaying- A Comprehensive Guide To Carotid Space Lesions
Case Study
Thu Jan 02 2025
CLINICAL DETAILS
A 44-year-old female presents with a history of multiple episodes of giddiness. The patient reports noticing swelling within her oral cavity, specifically in the area posterior to the right tonsillar pillar for 6 months. On clinical examination, there is no palpable swelling in the neck. However, a significant parapharyngeal swelling, approximately 4x4 cm in size, is observed in the oral cavity posterior to the right tonsillar pillar. This swelling is associated with a deviation of the uvula to the left. The clinical findings suggest a possible mass or lesion in the parapharyngeal space, warranting further investigation to determine the underlying aetiology.

IMAGING FINDINGS:
MRI reveals a well-defined, oval-shaped lesion in the right carotid space, measuring 3x4x5 cm. The lesion causes splaying of the internal and external carotid arteries and extends medially into the right parapharyngeal space. The lesion is iso to hyperintense on T1/T2WI and shows homogeneous postcontrast enhancement.
CT angiography of neck and brain showed the above-mentioned lesion to be hypoenhancing in the arterial phase.
The differential diagnoses considered were carotid body tumour, cervical sympathetic chain schwannoma and vagal schwannoma. Vagal schschwannomas displace the carotid arteries anteriorly rather than splaying them. Cervical sympathetic chain schwannomas displace the carotid arteries anteriorly but occasionally splay the internal and external carotid arteries without encasement. Carotid body tumours are usually pulsatile in nature, show multiple internal flow voids, splay and encase the carotid arteries, and show intense early enhancement followed by rapid washout. However, in our case, the mass showed progressive enhancement. Hence, in the given clinical setting and after reviewing the radiological features, a probable diagnosis of schwannoma was made.
FOLLOW-UP
Patient underwent surgery and it was found to be arising from the hypoglossal nerve and the biopsy revealed schwannoma.
DISCUSSION
Here are the possible causes of Lyre sign and the imaging features:

CONCLUSION
The ‘Lyre’ sign describes the characteristic splaying of the carotid artery bifurcation due to a carotid body tumour on conventional carotid angiography. This sign, however, is not diagnostic of carotid body tumours. An accurate diagnosis is, therefore, essential before embarking on invasive procedures such as biopsy or aspiration to prevent potential catastrophe.
As this case exemplifies, the road to a definitive diagnosis demands a synthesis of clinical acumen, imaging finesse, and sometimes, surgical intervention.
Bottomline: “Not all that splays is carotid body tumor”!!
Dr Adarsh Ishwar Hegde
KH site, Manipal
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Case Study
An Indian Spring - Unrest in the Chest
A 57 year old lady presented with a left chest wall nodule with a 3 week history. There was no other contributory history. This was a referral from an interventional radiologist and a core biopsy was submitted for histopathologic analysis. The radiologist’ impression included a soft tissue tumour and a hemato-lymphoid malignancy. No whole body imaging was available at the time.
The biopsy indicated a high grade, poorly differentiated large cell malignancy (pending immunohistochemical characterisation). Lesional tumor cells were set in a syncytial growth pattern with a streaming pattern seen focally, and found infiltrating between muscle bundles of the chest wall. Significant tumor emperipolesis was recorded.
Basis the morphology, a hemato-lymphoid malignancy was favoured over a soft tissue tumor. We circled back to the radiologist inquiring about the presence of multiple lymph nodes and/or lymph nodal masses or hepatosplenomegaly, if any. Whole body imaging was then ordered and lo and behold there was multiple lymphadenopathy found including, in the mediastinum together with bilateral renal enlargement present.
Stop press: in light of new radiologic findings coming to the fore, and presence of significant tumor emperipolesis as morphologic finding, our thoughts also turned to ‘biphasic squamoid’ papillary renal cell carcinoma (BPRCC) where emperipolesis is now accepted as a constant feature. However, in the present clinical context of chest wall nodule with multiple nodes in mediastinum and bilateral renal involvement, this was mooted as a remote possibility.
Immunostains were ordered for lymphoma work up and tumor cells were found reactive for CD45, CD20, CD30 and negative for T cell marker, CD43 as well as for ALK1. Cut to the chase, we now had a diagnosis favouring CD30 + anaplastic variant of DLBCL rather than a lymphocyte depleted Hodgkin disease which is the closest differential on immunohistology; absent a mixed inflammatory infiltrate and diffuse CD30 reactivity in the given case.

Next, a Hans algorithm was employed using CD10, bcl-6 and MUM1 to broadly stratify the DLBCL into two molecular prognostic groups: Germinal centre B cell (GCB) and activated B cell/ non GCB subtype. Note the GCB subtype has a better prognosis than the non GCB subtype. Our case yielded a CD10 — bcl 6 + and MUM1 + phenotype indicating a non GCB subtype and it follows therefore; a worse prognosis. Further and more, the International Prognostic index (IPI) lends itself handy as a clinical tool for predicting overall and progression free survival in DLBCL- something which is outside the scope of the current discussion.
No conversation on the DLBCL universe is ever complete without a refrain on ‘double hit’ and ‘triple hit status’ of the lymphoma. The double hit and triple hit status of DLBCL implies genetic rearrangement and/ or translocation of c- myc, bcl-2 or bcl-6 resulting in protein overexpression of these proteins (positive cut offs being defined at 70% of cells for c-myc and bcl-6 and 40% for bcl-2). Although protein expression by IHC is not a surrogate for cytogenetic testing, protein overexpression for c- myc, bcl-6 and bcl-2 can reliably indicate likely probability of double hit and triple hit status of lymphoma. Both double hit (DL) and triple hit lymphomas (TL) portend worse prognosis with poor response to chemotherapy and higher recurrence rates. In this instance, probability of a double hit lymphoma was considered less likely as c-myc and bcl2 proteins were not overexpressed in our case.
The final diagnosis offered was CD 30+ anaplastic variant of DLBCL, extranodal.
The received wisdom on testing for DL and TL status is that samples must be subjected for cytogenetic FISH based testing as it is more reliable and specific for these targets, and the same is incorporated into routine clinical practice.
As is wont to happen in non hospital based settings, the patient was referred to a tertiary care referral centre and lost to follow up.
To sum up, here we have an unusual extranodal presentation of a DLBCL (note extranodal DLBCLs are generally confined to gastrointestinal, skin, soft tissue, bone and genitourinary tract) wherein we are able to achieve prognostic stratification into two broad molecular subgroups on a targeted image assisted biopsy, enabling a ‘less is more’ approach to tumor diagnosis and prognosis with minimally invasive techniques of tissue sampling.

Case Study
The Fine Line: Pelvic Pitfalls: Deceptive Findings in Pelvic Ultrasound
Dr Praveen Shastry – Head of Technical and Clinical Academics, KH, Manipal.
Ultrasonography is undeniably one of the most powerful tools in modern diagnostic imaging, with its ability to provide real-time, dynamic views of soft tissues and organs. However, the effectiveness of an ultrasound scan hinges on more than just the technology—it’s the expertise and discernment of the radiologist that bring each image to life.
Achieving the right diagnosis with ultrasound depends on many factors: the quality of the equipment, patient cooperation, optimal bladder filling, minimal intestinal gas, and, of course, a vigilant and adaptable mindset from the operator.
Pelvic imaging is a realm where even the most seasoned radiologists can encounter surprising pitfalls, with structures that often imitate each other in unpredictable ways. This case series delves into common but deceptively tricky situations where a fleeting glance might lead to misinterpretation. Here, we aim to bring clarity to those subtle yet significant differences that distinguish one diagnosis from another.
Case 1:
Clinical History: A 32-year-old woman with a history of abdominal bloating and mild pelvic discomfort and menstrual irregularities presents for an ultrasound. The patient complains of intense urge to micturate and is also associated urinary frequency, denies any pain / burning sensation during urination.
Initial Ultrasound Appearance: Urinary bladder was completely distended showing no calculi within. Uterus visualized normal. One ovary visualized normal. Other ovary could not be distinctly visualized – The report was generated based on what was seen!
Twist in the tale: Follow up was requested by the referring clinician (Secondary to mild increase in discomfort) - Large midline structure was actually a pelvic cyst that initially masqueraded as a full bladder.
Conclusion: While this structure was mistaken for a bladder due to its midline location and symmetry, the absence of squarish margins, well-defined edges gave away the true identity. Absence of ureteric jet is another indicator in this instance.
Take-Home Punchline: "When in doubt, wait for the stream—it’s the bladder’s signature move!"
Case 2: The Gaslighted Ovary
Clinical History: A 32-year-old woman presents with lower abdominal pain and intermittent bloating. She’s had irregular cycles but no other significant symptoms.
Initial Ultrasound Appearance: A suspicious hyperechoic focus found adjacent to the left ovary resulting in scattered bright echoes. The report was issued – stating that there is excessive bowel gas.
Final Diagnosis: Ovarian teratoma (dermoid), with mixed echogenic components, including fat and calcifications, that mimicked gas.
Conclusion: Teratomas or dermoids, often contain odd tissue components, including fat, hair, and even bone, which produce confusing echoes similar to gas. Recognizing these unusual reflections can avoid misdiagnosis.
Take-Home Punchline: "Not all bubbles pop! When shadowing lingers, think teratoma."
Case 3: The Sneaky Salpinx
Clinical History: A 41-year-old woman with chronic pelvic pain and recent worsening discomfort visits the clinic. She has a history of pelvic infections but no surgical history.
Initial Ultrasound Appearance: Multiloculated cystic structure alongside the uterus- showing incomplete internal septations. Resembling a cyst, yet doesn’t fully match the typical round ovarian cyst shape.
Final Diagnosis: Hydrosalpinx, a fluid-filled, dilated fallopian tube.
Conclusion: The “cogwheel” sign from mucosal folds in hydrosalpinx can be mistaken for cysts. Its tubular shape and the absence of typical ovarian structures confirmed its true identity. The buzz word is incomplete internal septations!!!!
Take-Home Punchline: "Don’t get twisted—if it’s tubular with incomplete septae- think hydrosalpinx, not a cyst!"
Case 4: The Cyst that Cried Wolf
Clinical History: A 28-year-old woman with acute onset of sharp pelvic pain arrives in the emergency department. Her last menstrual period was two weeks ago, and she’s had no recent health changes.
Initial Ultrasound Appearance: A complex, echogenic structure appears within the ovary. It’s difficult to discern whether it’s a solid mass or a hemorrhagic cyst, as it contains both solid-looking regions and some cystic fluid.
Differentials: Solid adnexal mass, hemorrhagic ovarian cyst, or endometrioma.
Final Diagnosis: Hemorrhagic cyst, verified through repeat imaging as the appearance slowly resolved.
Conclusion: While hemorrhagic cysts can initially appear complex and solid-like, they typically resolve on follow-up, unlike true solid masses. Let time and patient stability guide management.
Take-Home Punchline: "If it’s complex and confusing, give it time—a tumor won’t back down."
Case 5: The Torsion Illusion
Clinical History: A 23-year-old woman with severe, sudden-onset right-sided pelvic pain presents to the emergency room. She’s nauseous, and painkillers have offered minimal relief.
Initial Ultrasound Appearance: The right ovary appears enlarged with a slightly irregular outline, though some blood flow is still detected on Doppler, raising doubts about torsion.
Final Diagnosis: Ovarian torsion confirmed intraoperatively despite preserved Doppler flow.
Conclusion: Ovarian torsion can sometimes retain blood flow due to dual blood supplies. When clinical signs point toward torsion, follow through, as Doppler alone may mislead.
Take-Home Punchline: “Flow isn’t everything! Look deeper—torsion’s a twisty foe.”
This collection of cases highlights some of the most misleading situations in pelvic ultrasound and provides memorable takeaways that are both practical and engaging.
By staying receptive to different possibilities, they avoid jumping to conclusions and instead build a nuanced, patient-centered diagnosis. In the world of ultrasound, it’s not just about seeing—it’s about seeing beyond.

Case Study
A Case Report: Pulmonary Nocardiosis in an Immunocompetent Patient
Dr Shanta Shubhra Das – Head, Department of Microbiology, Manipal TRUtest
BACKGROUND:
Nocardia species are Gram-positive, aerobic, catalase-positive bacteria within the Nocardiaceae family. They are classified based on morphological, biochemical, physiological, and chemotaxonomic properties. Nocardiosis is often an opportunistic infection, commonly affecting immunocompromised hosts. However, immunocompetent patients can also be affected, though less frequently.
The global incidence of nocardiosis is likely underestimated. In the U.S., annual cases range from 500–1000, with literature suggesting higher actual rates due to underreporting. Nocardia infections primarily involve the lungs, followed by the skin and central nervous system. Pulmonary nocardiosis accounts for 60–70% of cases.
We present a case of pulmonary nocardiosis in a 57-year-old immunocompetent male with a history of chronic obstructive pulmonary disease (COPD).
CASE PRESENTATION
A 57-year-old male patient was admitted to a private hospital with H/O fever, mild cough for 1 month and was evaluated in a community clinic but not cured. He was a smoker for last 32 years with no childhood history of respiratory disease. A chest x-ray showed consolidation on his left lung field. A clinical diagnosis of left pneumonitis was made. Enterococcus faecalis was isolated from his sputum. He was treated with Teicoplanin but his symptoms relapsed a few days later. He was re-treated with Linezolid for 7 days, his symptoms did not show improvement. The patient was referred to a tertiary care hospital for management of refractory pneumonitis.
On physical examination, his consciousness level was normal, pulse was 88 beats per minute, respiratory rate was 20 breaths per minute, blood pressure was 130/90 mmHg, temperature was 36.7 °C (98.1 °F), and oxygen saturation was 97%. Auscultation of his lungs revealed that there was decreasing lung sound in his left middle lung field. Laboratory evaluation showed an elevated WBC count of 17,500 /μL with 79.8% neutrophils, and a C-reactive protein level of 78 mg/dL. No pathogenic bacteria were isolated from a sputum culture this time. Patient was put on Levofloxacin for one more week, however his temperature increased to 39.3 °C with left sided chest pain, bloody sputum, and generalised weakness. The condition worsened in next 3-4 days. A chest x-ray showed consolidation on his left lung field. A chest computed tomography (CT) scan showed consolidation and atelectasis in his left middle lobe. He was diagnosed with Left sided pulmonary.
Administration of piperacillin/tazobactam improved the symptoms. On day 10 from admission, his right pleural effusion disappeared on chest x-ray, and CRP was decreased, and the patient was clinically improved. The patient was discharged on amoxicillin/clavulanate and asked for follow up visit after 1 week. After 2 weeks, the patient became febrile, and CRP was elevated to 56 mg/dL again. His lung abscess relapsed despite of intaking amoxicillin/clavulanate and he was admitted again. The patient was put on piperacillin/tazobactam and bronchoscopy was performed to find out the cause of relapse. Bronchial washing was send for aerobic culture and it showed Gram-positive, filamentous, branching filamentous bacteria in Gram stain. The culture grew Nocardia species from samples of the bronchial wash. Then the patient was switched to Cotrimoxazole. Susceptibility testing was performed according to Clinical and Laboratory Standards Institute (CLSI) document; the MIC value of Cotrimoxazole for Nocardia species was 0.25/4.75 and it was susceptible. Hence, Cotrimoxazole was continued. Treatment response was good, but renal dysfunction occurred 3 months later. We switched to minocycline 100 mg po BID for 1 month. After 1 month Chest X-ray showed no signs of consolidation, patient was clinically improved, and he has not relapsed.
DISCUSSION AND CONCLUSION
Pulmonary nocardiosis mainly occurs as an opportunistic infection in immunocompromised patients, such as patients with human immunodeficiency virus (HIV) infection and those receiving long-term systemic steroids or immunosuppressive agents. Pulmonary nocardiosis often occurs with chronic obstructive pulmonary disease (COPD) and bronchiectasis. We cannot point out any underlying disease that cause an immunocompromised state and no malignant disease has developed in the follow up period.
Susceptibility differs among the species. Cotrimoxazole is active against most Nocardia species; however, N. otitidiscaviarum is commonly resistant and N. nova and N. farcinica are occasionally resistant to Cotrimoxazole. So, it is important to identify of Nocardia species and determine antimicrobial susceptibility. However, we do not have enough resources to identify the exact species of this isolate. Still, from antibiotic susceptibility reporting Cotrimoxazole was susceptible to this Nocardia species and the patient responded and cured completely.
Only 7 cases of pulmonary nocardiosis were reported including our case. Most of the case reports were in immunocompromised patients. In the outcomes of all these cases, death by nocardiosis or poor response to treatment for Nocardia infection was evident.
In general, long-term treatment is recommended for patients with CNS lesions (ex. Brain abscess) or severe immunodeficiency, we considered the disappearance of the abscess as a goal of treatment.
In this case, the diagnosis was delayed. The patient initially was clinically improved following treatment with piperacillin/tazobactam on 1st admission. We could determine causative microorganism and antimicrobial susceptibility performing bronchoscopy on follow up. Although the symptoms improved with the initial treatment, the abscess remained even after the inflammation improved, so it is probable that he was infected with Nocardia at the time of initial hospitalization.
In conclusion, we reported a case of pulmonary nocardiosis caused by Nocardia species in an immunocompetent patient. The patient was treated with Cotrimoxazole and cured completely.