A retrospective search was made in the records of the Department of Pathology for histopathologically confirmed cases of soft tissue and muscular cysticercosis between August 2011 and January 2015. Medical records of the cases were reviewed for their clinical, radiological data. A total of 27 cases of soft tissue and muscular cysticercosis were included in the study. Two cases with inadequate clinical/radiological information were excluded from the study. Fine needle aspiration was performed using a 22-g needle and 10 ml syringe. Smears were separately wet fixed and air dried and stained with conventional Papanicolaou and Giemsa stain respectively according to the amount of aspirate. Excisional biopsy specimens were collected in 10% Formalin for fixation, processed for 18 hours in tissue processor, paraffin embedded and blocks were prepared. Sections were stained by Hematoxylin and Eosin method and mounted using DPX.

Among the total of 27 cases, 19 cases were noted in females with eight cases in males. The age of presentation of patients ranged from 8 years to 65 years. The most common site of lesion was in the arm (9 cases), forearm (8 cases), the abdominal wall (4 cases) thigh (3 cases) followed by neck (3 cases). The size of the lesion ranged from 8 mm to 5 cm in diameter. The clinical presentation of the lesions varied depending on the site of the lesion. No any correlation was noted between the symptom and size of the lesion. Clinically, cysticercosis was misdiagnosed as lipoma in most cases (11 cases) [Table/Fig-1,2]. Ultrasonographically, 24 cases were suggestive of cysticercosis. Three cases were inconclusive for the diagnosis of cysticercosis.

Histopathologically, intact cyst wall was noted in 12 cases, scolex in 5 cases. Ten cases showed degenerating cyst wall surrounded by inflammatory cells, granulation tissue and fibrosis [Table/Fig-3,4,5 and 6].

[Table/Fig-3]:

A 12-year-old girl with neck swelling who was clinically suspected as having lymphadenopathy

[Table/Fig-4]:

Muscular cysticercosis showing a small cystic nodule at the periphery of the tissue.

[Table/Fig-5]:

Photomicrograph showing well defined host capsule surrounding a cyst containing a parasitic larva characterized by thick tegument with knobby projections (H&E X40)

[Table/Fig-6]:

Photomicrograph showing scolex with suckers (H&E ×100)

On cytology, bladder wall of cysticercus were noted in majority cases (11 cases) followed by presence of hooklets in 6 cases in a background of mixed inflammatory cells [Table/Fig-2, 7].

[Table/Fig-7]:

Photomicrograph demonstrating Scimitar shaped hooklet and a neutrophil in the center on cytology (Giemsa X40)

Cysticercosis cellulosae, the larval stage of tapeworm Taenia solium is the causative agent of cysticercosis. Cysticercosis is endemic in many countries of the developing world posing a major public health problem [1]. Cysticercosis involves various organs of the body however involvement of the soft tissues and muscle is a relatively uncommon presentation [2]. The clinical presentation depends on the site of the lesion, larval burden as well as the host reaction. Subcutaneous cysticercosis presents as painless or painful subcutaneous nodules. Muscular cysticercosis has varied clinical presentation with frequently being asymptomatic to either of the described clinical manifestion: the myalgic, myopathic type; the nodular or masslike type; and the rare pseudohypertrophy type. In our series of cases, no any pseudohypertrophy type of presentation was noted which is relatively common in disseminated cases. In our study, the majority of the lesions were in the upper extremity which is similar to studies by Kala et al., and Handa et al., [3,4]. The prevalence of cysticercosis in Nepal has been shown to vary with gender, ethnicity, behavioral, environmental factor as well as geographical region [5]. There has been wide variation in the prevalence of Taenia in various studied population in Nepal with the highest 50% noted in the Magar community in Nepal [6].

Imaging has been crucial in the diagnosis of soft tissue cysticercosis as well as muscular cysticercosis [7]. Among various imaging modalities, ultrasound is found to be widely performed due to its feasibility and characteristic features. The sonological spectrum of soft tissue cysticercosis includes intramuscular abscess with an eccentrically situated typical cyst with a scolex within, typical cysticercosis cyst with a scolex within and surrounding mild edema but no abscess as well as irregular cyst with no scolex within [7,8]. Imaging has been indispensable in the diagnosis of cysticercosis in atypical presentation where there is clinical diagnostic dilemma as in one of our patient who was diagnosed with suppurative lymphadenitis [Table/Fig-2].

Fine needle aspiration cytology is the preferred initial pathological examination in the evaluation of subcutaneous nodules which is usually performed image guided in atypical cases [9,10]. Various studies have demonstrated the implication of FNAC in diagnosis of cysticercosis in subcutaneous nodules. Although, the presence of eosinophils, neutrophils, palisading histiocytes and giant cells in the aspirate suggest a possibility of parasitic entity; the diagnosis of cysticercus requires demonstration of fragment of larval cuticle and parenchyma. In keeping with various studies, scolex was not present in the cytological smears [11]. In equivocal cases, histopathological examination of biopsy specimen is fruitful in the diagnosis of cysticercosis. Definite diagnosis of cysticercosis can be made by demonstration of parts of parasite teguments, hooklets, parenchymatous portion and calcareous corpuscles.

It is important to have high degree of suspicion in patients hailing from or having history of travel to endemic regions for cysticercosis who present with any soft tissue or muscular cysticercosis. A clinico-pathological and radiological correlation is integral in such cases thus avoiding unnecessary intervention and patient morbidity.