Wednesday, February 13, 2013

osteoid osteoma

osteoid osteoma

Osteoid osteoma is a benign lesion that accounts for approximately 10% of benign bone tumors. It occurs predominantly in children and young adults between 10 and 25, affecting males twice as often as females. The clinical presentation typically consists of pain, which is often worst at night, increased skin temperature, sweating, and tenderness in the affected region. Pain is completely relieved by salicylates in many cases.
Predilection sites are proximal femur, and diaphysis of long bones, which account for more than half of all cases, and less often foot and the posterior elements of the spine (1). Osteoid osteomas are usually detected on radiographs, typically showing a radiolucent nidus surrounded by sclerosis in the cortex of the bone. If an osteoid osteoma is suspected and radiographs are negative, skeletal scintigraphy is especially useful with a sensitivity of 100% (2). Radionuclide angiography and tissue-phase imaging often, but not always, show prominent tracer delivery and early localization. On skeletal-phase images a well-localized, focal tracer uptake is typically noted (3). Characteristic is a cloud of diffuse increase of radiotracer around the prominent focus, which is better seen on images obtained with pinhole magnification technique (4). In complicated cases computed tomography might be helpful to visualize the nidus. Scintigraphy also is contributory for treatment of patients with osteoid osteoma by ensuring complete removal of the lesion. This can be achieved either by imaging the specimen that should demonstrate a normal margin of bone around the lesion or intraoperatively with a mobile gamma camera, demonstrating that no residual activity suggestive of osteoid osteoma tissue is left (5).


Authors: H.S.Das,P.Hatimota, P.Hazarika, C.D.Choudhury,
*S. K. Barua, **S.J.Baruah
Institution: Matrix, G.S.Road, Guwahati-5 and Guwahati Medical College & Hospital
Key Words: Adrenal cyst MRI
Conflict of interest: None


Cystic pathologies of the adrenal gland are rare with an incidence of 0.06% in 1400 autopsies. The cyst most commonly found in the adrenal gland are Endothelial cyst (45%), Pseudocyst (40%), Epithelial cyst ((9%) and Parasitic cyst (7%). Pseudocysts are consequences of haemorrhage and degeneration and are usually nonfunctional.
Pseudocysts consist of a hyalinized fibrous capsule containing nest of adrenal cortical cells and amorphous cystic contents composed of admixture of serum, blood and fibrin. Adrenal pseudo cyst vary greatly in size from microscopic to more than 50 cm with highest incidence in 5th and 6th decade with female preponderance.
Symptoms are usually associated with large cyst due to compression of surrounding viceras, pain & vague GI complaints. Imaging studies by CT scan & preferably by MRI Scan helps it to differentiate it from other adrenal pathologies. Surgical extirpation is indicated in presence of symptoms, endocrine abnormalities, complication, large size or suspicion of malignancy.
We report a case of symptomatic pseudo cyst of adrenal gland in an adult female without any hormonal abnormalities which was excised through thoraco-abdominal approach. Surgery was uneventful and patient is asymptomatic at 18 months of follow up.


A 35 years old female presented with a one year history of non specific abdominal discomfort & occasional pain in left upper abdomen. Routine laboratory tests were within normal range. USG showed a well defined approx. 10 cm cystic mass in relation to upper pole of left kidney. MRI showed a large cystic mass separated from upper pole of the kidney with a low signal intensity in T1 weighted images and high signal intensity in T2 weighted images. A complete endocrine workup failed to detect any hormonal hypersecretion. A prospective diagnosis of left adrenal cyst was made and the lesion was excised through thoraco-abdominal approach via 11th rib.
The cyst measured approx. 10 cm in its largest dimension which on cutting open revealed chocolate colored fluid. The wall thickness varied from 0.1 to 0.2 cm. and pathological section revealed fibrous wall without any epithelial lining. The patient had an uneventful post operative recovery. She is completely symptom free at 18 months of follow up visits.


Figures :

1- MRI :T@W coronal image showing well defined cystic lesion displacing the left kidney downwards suggesting suprarenal origin

2- Post operative specimen 
 3- Histopathology

Cysts of the adrenal gland are uncommon lesions and represent 80% of cystic adrenal masses. The etiology of pseudocyst is not well understood but is believed to arise from organization of prior haemorrhage or infectious process (1). Pseudocyst account for 40% of all cystic lesion of the adrenal gland and are consequences of haemorrhage and degeneration (2).
Most adrenal cyst are asymptomatic and less then 10 cm in diameter when discovered incidentally (3) or at autopsy (4). Symptoms appear when pseudo cyst enlarges sufficiently to cause pain and GI disturbances or become palpable (3) as in our patient. Large cyst has tendency to develop complications such as intractable haemorrhage and rupture which can manifest as a surgical emergency (5).

The haemorrhage within these lesions often give atypical imaging features on CT. Ultrasonography which could be confused with an adrenal tumor (6) . MRI is useful in differential diagnosis of adrenal cyst (7) and can differentiate it from pheochromocytoma (8).
MRI shows homogenously low intensity on T1 weighted images and high intensity on T2 weighted images in case of adrenal pseudo cyst (9, 10).
Pseudocyst may be isolated or associated with primary adrenal neoplasm such as Pheochromocytoma, adrenal adenoma, adrenocortical carcinoma and neuroblastoma (11). Pseudocyst could be confused with adrenal tumors both clinically and radiographically (12) . The more complex pseudocyst should be distinguished from cystic degeneration in adrenal malignancy and from cystic renal cell carcinoma in upper pole (2) .

Surgical excision is indicated in presence of symptoms (13), endocrine abnormality (even when subclinical), complications, large size (>5 cm) or suspicion of malignancy (14). Laparoscopic drainage (15, 16) or open surgical extirpation with preservation of adrenal tissue remains the treatment of choice. Large size, increased wall thickness or calcification are features of malignant changes which should be excised and followed up for cystic recurrence, late metastasis or adrenal endocrine dysfunction.
Other lesions that should be considered in the differential diagnosis of cystic adrenal masses are endothelial cyst, lymphangioma, epithelial cyst and parasitic (hydatid) cysts (17, 18).


1. M.A.Habra , Barry W Feig , Steven G Waguespack. , Adrenal Pseudocyst
The Journal of Clinical Endocrinology and Metabolism, 2005; 90(5) : 3067-68

2. Guensens E , De Man R, Van Oost J, Vuylsteke P., Large Adrenal Pseudocyst
, J . Belge. Radiol. 1993 ; 76(5): 322-3

3. Tagge D U , Baron P L , Giant adrenal cyst : Management and review of literature
Am. Surg. 1997; 63(8) : 744-6

4. Luciano AFavorito, Felipe M. Lott, Andre G Cavalcante. Tarumatic
rupture of adrenal pseudocyst leading to massive haemorrhage in
retroperitoneum , Int. Braz. J Urol. 2004; 30 (1), Abstract from SciELo Brazil

5. Chew S P, Sim R , Teoh TA , Low CH. , Haemorrhage in to non functional adrenal
cyst- report of two cases and review of literature. Ann. Acad. Med. Singapore
1999;28: 863-6

6. Sakamoto I , Nakahara N. , Fukuda T. et. al . , Atypical appearance of Adrenal
Pseudocyst. J Urol, 1994;154(1): 150-2

7. Ito N., Fujimoto H, Arai Y, Nishimura K et. al. Two cases of adrenal cyst- the
meaning of imaging in diagnosing adrenal cyst. Hinyokika Kiyo, 1989;35(7): 1161-6

8. Hidetaka Suga et. al. , 14C, Jan 2003; 42(1) Crossed ref. Medline

9. Yashushi Tanuma , Makoto Kimura , Shigeru Sakai. Adrenal Cyst- A review of the
Japanese Literature and report of a case. International Journal of Urology, 2001;
8: 500

10. Chihangir Erem , Fatih Celik , Abdulkadir Reis et. al. Large adrenal pseudocyst
presenting with epigastric distress and abdominal distension ,
Medical Principle & Practice, 2005; 14: 284-87

11. Erickson L.A., Lloyd RV , Hrtman R , Thompson G. , Cystic Adrenal Neoplasm,
Cancer, 2004; 101: 1537-44

12. deBree E., Schoretsanitis G , Melissas J et. al. , Cyst of Adrenal Gland: Diagnosis and
management , Int. Urol. Nephrol., 1998; 30(4): 369-76

13. N. Sezhian, D. Rimal , G Suresh . Adrenal Pseudocyst- Diagnostic Dilema
,Scottish Medical Journal, 2005; 45(2): 81

14. Manuel Suarez, Sheldon Bastacky, Vascular adrenal cyst . Final Diag. Case- 182,
2005, Crossed ref. Medline

15. Koksoy Ferda N , Yucel Osman , Celik Atilla et. al. Laparoscopic management of giant
adrenal cyst : Case report , Surg. Lap. End. PCN Technique, 2001;11(6); 379-81

16. Prashad R., Kumar M., Pseudocyst of adrenal gland,
Med. J, Malayasia, 2002; 57(1): 125-7

17. Satou T.,Uesugi T , Nakai Y et. al. , Case of adrenal lymphangioma with atypical
lymphocytes in aspirate cytology. Diag. Cytopathol., 2003; 29: 87-90

18. Ackay MN , Akcay G, Balik AA , Boyuk A , Hydatid cyst of the adrenal gland : review
of nine patients. World J Surg, 2004;28: 97-99

* Registrar Deptt of Urology, GMCH
** Prof Deptt of Urology, GMCH

Address for Correspondence:
Dr Himadri Sikhor Das,
Matrix,1st Byelane Tarun Nagar
Near Rajiv Bhawan, G.S.Road,

Differentials of G.I diseases

Metastatic squamous neck cancer with occult primary:

Metastatic squamous neck cancer with occult primary: 


The diagnosis of an occult primary tumor is made only if no primary tumor is detected after careful search, and it does not appear during therapy. Patients with cervical lymph node metastases histologically related to a previously treated primary tumor as well as patients with lymphomas and adenocarcinoma are excluded. If the 
biopsy is an undifferentiated carcinoma (in particular, a lymphoepithelioma), the most probable primary site is in Waldeyer's ring; for example, the nasopharynx, base of tongue, or tonsil. Most epidermoid carcinomas metastatic to lymph nodes of the upper half of the neck will originate from a head and neck primary site. Squamous carcinomas metastatic to the lower neck may represent a primary site in the head and neck, esophagus, lung, or genitourinary tract. A search for primaries in these areas must be undertaken before 
assuming that the primary is occult. Primary tumors cryptically arising in the nasopharynx may be secondary to Epstein-Barr Virus (EBV) infection, and EBV genomic material may be detectable in cervical nodal tissue after DNA amplification using the polymerase chain reaction. Such a finding should lead to an in-depth search for 
a primary in the nasopharynx.[1] The extent of investigation and type of treatment must be individualized depending on the age of the patient, site, and extent of the metastatic lymph node involvement, histology, and patient's wishes. When a patient qualifies as having squamous carcinoma of the neck with occult primary, check for other obvious metastatic disease, such as lung, liver, or bone, since this would affect the locoregional approach to therapy.[2] \Three-year disease-free survival rates following surgery and/or radiation therapy for unknown squamous primaries range from 40%-50% in N1 patients to 38% and 26% for N2 and N3 disease, respectively. Patients who later develop primary lesions have poor survival rates compared to those patients whose primaries remain occult, for example 30% versus 60%. A patient with neck metastases from an undetectable primary should not be abandoned but given the benefit of definitive treatment. significant number of patients do achieve cure by both surgical and radiotherapeutic approaches. In some patients, long-term repeat 
examinations will eventually disclose the primary tumor, and at a treatable stage. 


This section helps lead the clinician and pathologist through a differential diagnosis for an unknown primary presenting with cervical node metastases. The therapeutic section, however, relates only to squamous carcinoma and assumes that the primary physician has worked with the pathologist as described below to eliminate 
other possibilities that would require alternative therapies. The pathologist plays a central role in evaluating an occult primary tumor. A thorough evaluation of an adequate specimen through histologic or immunohistochemical techniques, and, when appropriate, electron microscopy (EM) provides guidance for the clinical evaluation that ensues. A critical interaction should exist between the pathologist, oncologist, and primary physician. 

The complexity of the pathologic evaluation tends to be inversely related to the degree of differentiation of the tumor. For instance, for well or moderately differentiated tumors, the pathologic diagnosis of an epithelial cancer is often readily apparent, in contrast to lymphoma, sarcoma, melanoma, or a germ cell tumor. 
Commonly used stains such as mucicarmine or diastase-sensitive Periodic Acid Schiff (PAS) can be important in confirming the diagnosis of certain tumors of gastrointestinal or renal origin. If the clinician is faced with a male patient less than 50 years of age with a poorly differentiated tumor, serum levels of bHCG and AFP 
should be obtained and specimens should be evaluated with immunohistochemical stains for bHCG and AFP. Certain of these tumors respond to platinum-based combination chemotherapy in a manner similar to extragonadal germ cell malignancies, and this group of patients should be so treated unless other alternative diagnoses are made.

Special studies can help in differentiating more poorly differentiated tumors. Often, a generic distinction is important between a poorly differentiated tumor of epithelial, hematopoietic, neuroendocrine, or neuroectodermal origin (i.e., melanoma). Immunohistochemical: Immunohistochemical studies can be important in making these broad distinctions, in particular, studies that evaluate staining for keratins, leukocyte common antigen (LCA), and 
S-100, a neuroectodermal antigen expressed in melanomas. Polymerase chain reaction: In patients with suspected nasopharyngeal carcinoma, DNA amplification of Epstein-Barr virus (EBV) genomes can be used for diagnosis with tissue provided by fine-needle aspiration biopsy. The presence of EBV in metastases from an occult primary tumor suggests the development of overt nasopharyngeal carcinoma.

Acinar spaces and microacini are seen with adenocarcinomas. Electron dense secretory granules are seen in tumors of neuroectodermal origin. Premelanosomes can be found in most amelanotic melanomas. But these features are generally associated with differentiation along a particular line. Often poorly differentiated tumors do not display such characteristics, and EM evaluation would be of little value. Electron microscopy may aid in distinguishing a primary diagnosis not obtained by light microscopy approximately 10% of the time.[4-6] 



The American Joint Committee on Cancer (AJCC) has designated staging 
by TNM classification.[1] 

TNM definitions

There is no tumor classification (T) for occult primary cancer metastatic to neck lymph nodes. 
Regional lymph nodes (N) The following regional node classification is applicable to all squamous carcinomas of the upper aerodigestive tract: 

NODES: Regional lymph nodes cannot be assessed N0: No regional lymph node metastasis N1: Metastasis in a single ipsilateral lymph node, 3 cm or less in greatest dimension N2: Metastasis in a single ipsilateral lymph node, more than 3 cm but not more than 6 cm in greatest dimension, or in multiple ipsilateral lymph nodes, none 
more than 6 cm in greatest dimension, or in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension N2a: Metastasis in a single ipsilateral lymph node more than 3 cm but not more than 6 cm in greatest dimension N2b: Metastasis in multiple ipsilateral lymph nodes, none more than 6 cm in greatest 
dimension N2c: Metastasis in bilateral or contralateral lymph nodes, none more than 6 cm in greatest dimension N3: Metastasis in a lymph node more than 6 cm in greatest dimension 

In clinical evaluation, the actual size of the nodal mass should be measured and allowance should be made for intervening soft tissues. Most masses over 3 cm in diameter are not single nodes but are confluent nodes or tumor in soft tissues of the neck. There are 3 stages of clinically positive nodes: N1, N2, and N3. The use of 
subgroups a, b, and c is not required but recommended.Midline nodes are regarded as homolateral nodes. 

Distant metastasis (M) MX: Distant metastasis cannot be assessed M0: No distant metastasis M1: Distant metastasis There is no generally accepted Roman numeral staging system for this disease. 


Untreated metastatic squamous neck cancer with occult primary means that a patient is newly diagnosed and has had no prior treatment except supportive care. 



Patients with neck nodes from a presumed unknown primary tumor should be evaluated as follows: 1. Surgical biopsy or excision to establish a histologic diagnosis, but only after an aerodigestive tract primary has been carefully ruled out as in the following procedures: 

2. Direct nasopharyngoscopy, laryngoscopy, bronchoscopy, and esophagoscopy, with biopsy of any suspicious area.If no suspicious lesions are found, random biopsies of the nasopharynx, base of tongue, tonsil, and pyriform sinus on the side of the lesion should be performed. If the tonsil is not present, biopsy of the tonsillar fossa should be performed. Sinus x-rays are probably indicated; if abnormality is found, it should be biopsied as well. 

3. Selected other studies if indicated.In the detection of head and neck tumors and in the distinction of lymph nodes from blood vessels, magnetic resonance imaging (MRI) offers an advantage over CT scans and should be considered in the initial evaluation of the patient with metastatic squamous cell cancer in cervical lymph nodes.

Patients should be managed with either a full course of radiation therapy or adequate neck dissection, when possible. In cases of massive homolateral adenopathy that is fixed or bilateral nodes, radiation therapy should be administered first. The radiation fields should also include the nasopharynx, base of tongue, and pyriform sinuses. If radiation therapy is the primary mode of treatment and the neck mass persists upon completion of radiation therapy, cervical lymph node dissection should be performed. Patients with metastatic carcinoma in the supraclavicular region are best managed with a full course of radiation therapy followed by surgical dissection if palpable tumor persists. Careful continued follow-up of these patients is of utmost importance. Depending on the likely site of origin and histology, chemotherapy appropriate to the most treatable site may be indicated. 

Accumulating evidence has demonstrated a high incidence (>30%-40%) of hypothyroidism in patients who received external-beam irradiation to the entire thyroid gland or the pituitary gland. Thyroid function 
testing of patients should be considered prior to therapy and as part of post-treatment follow- up.

Treatment options: 
1. Radical neck dissection. 
2. Radiation therapy.[5,6] 
3. Combined surgery and radiation therapy.

Under clinical evaluation: 
1. Chemotherapy followed by radiation therapy. 
2. Simultaneous chemotherapy and hyperfractionated radiation 
3. Clinical trials for advanced tumors should be considered.

Differential diagnoses of Adrenal Masses :

Differential diagnoses of Adrenal Masses :


· Smooth contour and well marginated, diameter less than 5 cm.
· May appear heterogeneous due to cystic degeneration or hemorrhage.
· If a functioning adenoma, may have report of hypersecretion of cortisol (Cushing’s syndrome), aldosterone (Conn’s syndrome), or androgens (adrenal virilization). Correlate clinically.

Cushing’s syndrome

· Unilateral mass with decrease in size of contralateral gland.
· Usually 2-4 cm diameter lesion.

Conn’s syndrome

Hypoattenuating lesion in gland with average diameter less than 2 cm (need thinner cuts to visualize). 

· Hyperplasia 
o Have diffuse enlargement bilaterally.
o A variant called macronodular hyperplasia shows not only thickened adrenals but multiple nodules.
o Clinically will have hyperfunctioning gland.

· Carcinoma
o Very rare.
o Size is often greater than 5 cm with central areas of necrosis, may have tumor calcification.
o Tumor may demonstrate spread into the lever, nodal system or venous system.

· Metastasis
o The adrenals are the fourth most common location for metastatic disease. In most cases, patients are asymptomatic.
o Appearance on CT is widely variable, but there are five patterns commonly seen :
o Mass less than 5 cm in diameter.
o Mass greater than 5 cm in diameter.
o Multiple masses.
o Diffuse enlargement.
o Normal appearing glands.
o It is frequently difficult to distinguish a nonhyperfunctioning adenoma from a metastasis in cancer patients. 
o In non-cancer patients, an adrenal mass less than 5 cm in size with no features consistent with malignancy should be followed with serial CT scans. If after 18 months the lesion is stable, it can be considered benign.


· Typically greater than 3 cm, and if large, may be cystic due to necrosis.
· Because of hypervascular nature, will enhance brightly with contrast.
· May contain calcification.
· Clinically will have hyperfunction, with increased urinary levels of catecholamines.
· If associated with MEN syndrome or von Hippel-Lindau disease, may have lesions in pancreas, kidney and spinal cord.
· If difficult to differentiate from adenoma, perform T2-weighted MR. Pheochromocytoma will have significantly higher signal intensity.


· Round to oval adrenal mass.
· In adults, is typically related to blunt abdominal trauma, and if so is usually right sided.
· Acute to subacute hematomas have attenuation values between 50 and 90 HU. Follow up studies will demonstrate decrease in size and attenuation.


· Unilateral and solitary hypoattenuating mass.
· Usually round or ovoid with thin, smooth wall.
· Inferior wall may be flat or even concave.
· May see peripheral, curvilinear calcification.


· Granulomatous infection
o The most common infectious cause of Addison disease is tuberculosis.
o Early adrenal findings include bilateral enlargement with a hypoattenuated center & an enhancing rim. Later the adrenal atrophies with calcification
o With disseminated histoplasmosis, CT demonstrates bilateral enlargement again with central hypoattenuation and a peripheral rim. Diagnosis can be made with FNA biopsy and special staining.

· Pneumocysitis carinii infection
o Consider in immunocompromised patient population.
o On unenhanced CT will see either punctate or coarse calcifications in multiple abdominal structures including the adrenals, liver, spleen, kidneys and lymph nodes.

· Abscess
o Most adrenal abscesses are found in neonates who have had a prior adrenal hemorrhage.
o On contrast-enhanced CT will see thick-walled cystic mass.


· Usually asymptomatic unless hemorrhage within the mass causes symptoms. 
· Consist of mature fat and bone marrow. Appearance ranges from nonfatty soft tissue mass to a fat predominated mass. Typically unilateral, may be calcified, especially if had previous hemorrhage.
· Most commonly has a well-defined capsule surrounding fat. Attenuation ranges especially if had previous hemorrhage.
· With contrast, the soft-tissue areas will enhance, potentially masking the areas of fat.


· Rare benign tumor that is a well-defined hypoattenuating or heterogeneously attenuating mass, often containing calcifications.
· A characteristic finding is phleboliths within the haemangioma.


· Homogeneous hypoattenuating lesions in comparison to muscle on both enhanced and unenhanced CT, may have calcification.
· CT-guided biopsy or surgical resection necessary to confirm diagnosis.